Tag Archives: influenza

Here’s what you need to know about the new flu vaccines for over-65s

The Conversation

File 20180219 75964 fij0f6.jpg?ixlib=rb 1.1
Older people’s immune systems don’t respond to flu vaccines as well as younger people’s. Shutterstock

Allen Cheng, Monash University

In an attempt to avoid a repeat of last year’s horror flu season, Health Minister Greg Hunt yesterday announced the government would fund two new flu vaccines in 2018 to try to better protect the elderly.

While influenza affects people of all ages, infections among the elderly are more likely to require hospitalisation or cause serious complications such as pneumonia and heart attacks. Of the 1,100 Australians who died last year from flu-related causes, 90% were aged 65 and over.

The two free vaccines for over-65s work in different ways: FluZone High Dose is a high-dose version; Fluad adds an additional ingredient to boost its effectiveness. Both are recommended for use only in people aged 65 and over. But neither is perfect. And it’s important to remember flu vaccines are, at best, only partially protective.

Why do we need new vaccines for flu?

Australia’s National Immunisation Program provides free influenza vaccine for the elderly, as well as other high-risk groups including pregnant women, those with chronic diseases and Indigenous Australians.


Read more:
Flu vaccine won’t definitely stop you from getting the flu, but it’s more important than you think


Older people’s immune systems don’t respond to flu vaccines as well as younger people’s. Recent studies have also shown that flu vaccines don’t appear to be as effective in the elderly at protecting against flu and its complications.

Compounding this problem is that the flu subtype that tends to affect older people (A/H3N2) is different to that which affects younger people (A/H1N1).

Although the seasonal flu vaccine now contains four strains to cover all the relevant subtypes present, the protection against H3N2 infection appears to be poorer than against other strains.

Two strategies are attempting to improve the effectiveness of flu vaccines. One is to increase the dose of the flu strains in the vaccine. This is the basis for Sanofi’s High Dose FluZone vaccine, which contains four times the amount of flu antigen than the standard dose.

Another way is to add a substance that improves the immune response, known as an adjuvant, in combination with the flu strains. This is the basis for Seqirus’ (CSL) Fluad vaccine, which contains the adjuvant MF59. This vaccine has been used overseas for many years, but has only been become available in Australia this year.

How much better are these vaccines than the current vaccine?

Compared to the standard flu vaccine, the high-dose version has been shown to better stimulate the immune system of older users to make protective antibodies.

It has been shown to better reduce rates of flu infection in over-65s than the standard vaccine. And, interestingly, it also seems to protect against pneumonia.

One common criticism of clinical trials is that they don’t include the types of people who are found in the “real world”. But population based observational studies suggest that the high-dose vaccine is more protective than the standard-dose vaccine where H3N2 is the predominant circulating strain – as it was last year.


Read more:
Here’s why the 2017 flu season was so bad


What about the Fluad (adjuvanated) vaccine?

Compared to the standard vaccine, adjuvanted flu vaccine has been shown to better stimulate the immune system of older users to make protective antibodies.

Unlike the high-dose vaccine, there have not been clinical trials that show a difference in infection rates compared with the standard vaccine. But observational data suggests the adjuvanted vaccine is more protective against hospitalisation with influenza or pneumonia – to a similar degree as the high-dose vaccine.

One problem with both these vaccines is that they only contain three strains, rather than the four strains in the current vaccine. The strain missing from the new vaccines is an influenza B type.

But the benefits of better protection against the most common three strains in the new vaccine appear to outweigh the potential loss of protection against the missing B strain.

The newly available vaccines provide addition protection for over-65s. Sladic/Shutterstock

Are the new vaccines safe?

Both vaccines are safe, but commonly cause mild side effects, and very rarely can cause serious side effects. However, these risks from the vaccine are less than from getting influenza infection.

The main side effect of vaccines relates to their effect in stimulating the immune system. In many people they cause a sore arm and, less commonly, a fever. The side effects of these new flu vaccines are slightly more common than with standard vaccines. Generally, these side effects are mild and don’t last long.

None of the flu vaccines used in Australia contains live virus and therefore can’t cause flu infection. However, the vaccination season (April to June) usually occurs around the same time as when another respiratory virus (RSV) circulates, so this respiratory infection is commonly misattributed to vaccination.


Read more:
Health Check: when is ‘the flu’ really a cold?


Rare but serious side effects, such as Guillain Barre Syndrome (where the immune system attacks nerves), have been described after flu vaccination. Studies suggest that the risk of these side effects are less common after the flu vaccine than after flu infection.

People with allergies should discuss flu vaccines with their doctor. In the past, there has been concern that the flu vaccines, which are manufactured in eggs, may elicit allergic reactions in people with egg allergy. However, it is now thought that people with egg allergies can receive flu vaccines safely under appropriate supervision.

In 2009, an adjuvanted vaccine (Pandemrix) was thought to be implicated in cases of narcolepsy (a disease associated with excessive sleepiness) in Europe. However, this primarily occurred in children (rather than the elderly), and with a different adjuvant (ASO3) than is being used in Fluad (MF59)

Which vaccine should I get?

The two vaccines have not been compared head to head, so it isn’t known which one is better. The available data suggest they are similar to each other.

In practice, what vaccine you’ll receive will depend on what’s available at your GP or pharmacy.

It is important to note that these vaccines are only recommended for use in people 65 years of age or older, and are not recommended for use in people under this age.

The standard vaccine will still be available for younger people. There are no data to support the use of multiple doses of vaccines of the same or different types.


Read more:
Flu is a tragic illness. How can we get more people to vaccinate?


Neither of the new vaccines is perfect – they simply reduce your risk of getting flu to a slightly greater effect than the standard vaccine. Like other flu vaccines, there is still the chance that the vaccine strains don’t match what’s circulating.

The ConversationDespite the common perception that the flu is mild illness, it causes a significant number of deaths worldwide. To make an impact on this, we need better vaccines, better access to vaccines worldwide and new strategies, such as increasing the rate of vaccination in childhood.

Allen Cheng, Professor in Infectious Diseases Epidemiology, Monash University

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Flu is a tragic illness. How can we get more people to vaccinate?

The Conversation

File 20170921 16560 1nqeo0y
Most people don’t take flu seriously enough. from http://www.shutterstock.com.au

Julie Leask, University of Sydney and Samantha Carlson, University of Sydney

Flu (influenza) has traditionally been the underdog of vaccine-preventable diseases. People tend not to worry about the flu too much, and there are various myths about its prevention and the vaccine. It’s true most people experience flu as a mild disease, but many don’t recognise it can be more severe.

Each year flu is estimated to kill at least 3,000 Australians aged over 50 years alone. It took more children’s lives than any other vaccine preventable disease in Australia between 2005-2014, and is the most common vaccine preventable disease that sends Australian children to hospital.

The tragic death of eight-year-old Rosie Andersen from flu this week has followed the recent outbreaks in aged care facilities and subsequent deaths of residents in South Australia, Tasmania and Victoria. A 30-year-old father died earlier this month due to complications from the flu, and now Sarah Hawthorn, who was infected late in her pregnancy, remains in a coma, unaware her baby was safely delivered six weeks ago.

This year’s flu season has been a bad one. And it’s not over yet.

Australian studies have shown the flu vaccine can usually reduce the risk of flu in those who are vaccinated by 40-50%, and by 50-60% for children. Early indications are showing the effectiveness of this year’s flu vaccine may be lower.

Experts are calling for a better vaccine, which is needed. But even a more effective vaccine won’t address all the barriers to uptake.


Read more: Flu vaccine won’t definitely stop you from getting the flu, but it’s more important than you think


Who’s most at-risk?

Annual flu vaccination is recommended for any person six months of age or older who wishes to reduce the likelihood of becoming ill with flu. It’s free for certain groups at higher risk of the severe effects of the disease including:

• people over 65 (80% of whom are vaccinated)

• Aboriginal and Torres Strait Islander people from six months to five years (12% of whom are vaccinated)

• Aboriginal and Torres Strait Islander people over 15 (34% of whom are vaccinated)

• pregnant women (45% of whom are vaccinated)

• people aged six months and over with medical conditions such as severe asthma, lung or heart disease, low immunity or diabetes (58% of these adults are vaccinated, and 27% of these children).

Why don’t they vaccinate?

Researchers have looked at why many people in these groups don’t have their yearly flu vaccine. A common theme emerges – health professionals are not recommending it enough, people aren’t aware they need it, they’re not sufficiently motivated, or they don’t have easy access.

These themes come out in studies with parents of young children, pregnant women, Aboriginal and Torres Strait Islander children, adults with other disease, and people over 65.

The flu vaccine isn’t free for all kids. from http://www.shutterstock.com

Our research is now looking at the children who end up in hospital with severe flu. We’re trying to better understand the barriers to flu vaccination, along with vaccine efficacy issues.

We’ve heard that not only are health care workers not recommending it enough, some doctors are even recommending against it, as they don’t believe the child is at risk. This is even though over half of children hospitalised from the flu are those without medical risk factors. Other times it’s simple awareness – parents didn’t know their child can receive a flu vaccine if they’re over the age of six months.

Busy lives can mean making time to go to the clinic for a vaccine falls down the list of priorities. A four-year-old in our study was hospitalised only three days before a visit to the clinic had been booked.

Some of the children in our study were not theoretically at high risk of flu and so not in the group where the vaccine is free. This was a major barrier, as it has been in other studies in children and adults. Parents report to us that their child is up-to-date with their scheduled vaccines, but annual flu vaccination is not being ticked off as it’s not on the schedule.

The challenge with flu vaccine is it’s given yearly. In the UK it’s recommended and funded for all children of primary school age using a school-based delivery program and currently between 53-58% of children have it. When this many children are vaccinated there can be indirect protection of others who are not vaccinated because the virus is not able to spread from person to person as easily.


Read more: I’ve always wondered: why is the flu virus so much worse than the common cold virus?


Misconceptions about the flu vaccine

Misconceptions about flu vaccine are also a barrier: that it causes flu, that it’s not effective, that it’s not needed. People might say they never get the flu, not realising symptoms can be mild or not noticed and they can pass it on to the vulnerable. Others reported their belief was that the flu was not a serious disease. Some believed contracting flu “naturally” was likely to provide greater immunity.

Some parents also have concerns about the safety of the flu vaccine. Australians were spooked by a 2010 incident when there was a temporary suspension of flu vaccine for children under five after reports of an increase in the rate of convulsions in children.

The one vaccine found to be the cause (BioCSL/Sequiris Fluvax™) is no longer approved for use in children younger than five, but there are other seasonal flu vaccines children can have. But public and professional confidence is yet to fully recover, despite having reassuring safety data.

People may say they never get the flu so they don’t need the vaccine, but you can pass on the virus without knowing you have it. from http://www.shutterstock.com

Western Australia has had a free child vaccine program for years which was achieving relatively good coverage, but this dramatically declined after 2010, and coverage languishes at around 15% today. In other words, mud sticks.

How to improve uptake

To improve uptake we first need timely and accurate coverage figures. We now have the capacity to get coverage estimates from the expanded Australian Immunisation Register but these are not yet available.

The vaccine needs to be recommended more often, available more readily, free and recommended as part of the schedule, and myths addressed more effectively.

We need to motivate and support health care workers to implement the recommendations, such as with automated reminders, incentives and performance indicators. Systems need to ensure people can get the vaccine easily – from the GP or other health clinic, the specialist clinic, the antenatal care clinic, or from an Aboriginal or Torres Strait Islander health worker.

The ConversationPromoting flu vaccine to everyone is important, as is providing ease of access, awareness and opportunity. Although the flu vaccine isn’t perfect, it’s far better than no protection at all.

Julie Leask, Associate Professor, University of Sydney and Samantha Carlson, Research Officer for the National Centre for Immunisation Research and Surveillance, University of Sydney

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Health Check: which vaccinations should I get as an adult?

The Conversation

File 20170810 4244 1cw5cph
Vaccines are one of the greatest public health achievements in history. from shutterstock.com

C Raina MacIntyre, UNSW and Rob Menzies, UNSW

Before vaccines were developed, infectious diseases such as diphtheria, tetanus and meningitis were the leading cause of death and illness in the world. Vaccines are one of the greatest public health achievements in history, having drastically reduced deaths and illness from infectious causes.

There is a large gap between vaccination rates for funded vaccines for adults in Australia and those for infants. More than 93% of infants are vaccinated in Australia, while in adults the rates are between 53-75%. Much more needs to be done to prevent infections in adults, particularly those at risk.

If you are an adult in Australia, the kinds of vaccines you need to get will depend on several factors, including whether you missed out on childhood vaccines, if you are Aboriginal or Torres Strait Islander, your occupation, how old you are and whether you intend to go travelling.

For those born in Australia

Children up to four years and aged 10-15 receive vaccines under the National Immunisation Schedule. These are for hepatitis B, whooping cough, diphtheria, tetanus, measles, mumps, rubella, polio, haemophilus influenzae B, rotavirus, pneumococcal and meningococcal disease, chickenpox and the human papillomavirus (HPV).

Immunity following vaccination varies depending on the vaccine. For example, the measles vaccine protects for a long duration, possibly a lifetime, whereas immunity wanes for pertussis (whooping cough). Boosters are given for many vaccines to improve immunity.

Measles, mumps, rubella, chickenpox, diphtheria and tetanus

People born in Australia before 1966 likely have natural immunity to measles as the viruses were circulating widely prior to the vaccination program. People born after 1965 should have received two doses of a measles vaccine. Those who haven’t, or aren’t sure, can safely receive a vaccine to avoid infection and prevent transmission to babies too young to be vaccinated.

Measles vaccine can be given as MMR (measles-mumps-rubella) or MMRV, which includes varicella (chickenpox). The varicella vaccine on its own (not combined in MMRV) is advised for people aged 14 and over who have not had chickenpox, especially women of childbearing age.

Booster doses of diphtheria, tetanus and whooping cough vaccines, are available free at age 10-15, and recommended at 50 years old and also at 65 years and over if not received in the previous ten years. Anyone unsure of their tetanus vaccination status who sustains a tetanus-prone wound (generally a deep puncture or wound) should get vaccinated. While tetanus is rare in Australia, most cases we see are in older adults.


In July 2017, the government announced free catch-up vaccinations for all newly arrived refugees. This covers any childhood vaccine on the National Immunisation Schedule which has been missed.
Information sourced from betterhealth.vic.gov.au and healthdirect.gov.au/The Conversation, CC BY-ND

Whooping cough

Pregnant women are recommended to get the diphtheria-tetanus-acellular pertussis vaccine in the third trimester to protect the vulnerable infant after it is born, and influenza vaccine at any stage of the pregnancy (see below under influenza).

Pertussis (whooping cough) is a contagious respiratory infection dangerous for babies. One in every 200 babies who contract whooping cough will die.

It is particularly important for women from 28 weeks gestation to ensure they are vaccinated, as well as the partners of these women and anyone else who is taking care of a child younger than six months old. Deaths from pertussis are also documented in elderly Australians.


Read more: ‘No Vax, No Visit’? If mum was vaccinated baby is already protected against whooping cough


Pneumococcal disease and influenza

The pneumococcal vaccine is funded for everyone aged 65 and over, and recommended for anyone under 65 with risk factors such as chronic lung disease.

Anyone from the age of six months can get the flu (influenza) vaccine. The vaccine can be given to any adult who requests it, but is only funded if they fall into defined risk groups such as pregnant women, Indigenous Australians, peopled aged 65 and over, or those with a medical condition such as chronic lung, cardiac or kidney disease.

Flu vaccine is matched every year to the anticipated circulating flu viruses and is quite effective. The vaccine covers four strains of influenza. Pregnant women are at increased risk of the flu and recommended for influenza vaccine any time during pregnancy.


Read more: Millions of Australian adults are unvaccinated and it’s increasing disease risk for all of us


Health workers, childcare workers and aged-care workers are a priority for vaccination because they care for sick or vulnerable people in institutions at risk of outbreaks. Influenza is the most important vaccine for these occupational groups, and some organisations provide free staff vaccinations. Otherwise, you can ask your doctor for a vaccination.

Any person whose immune system is weakened through medication or illness (such as HIV) is at increased risk of infections. However, live viral or bacterial vaccines must not be given to immunosuppressed people. They must seek medical advice on which vaccines can be safely given.


In July 2017, the government announced free catch-up vaccinations for all newly arrived refugees. This covers any childhood vaccine on the National Immunisation Schedule which has been missed.
Information sourced from betterhealth.vic.gov.au and healthdirect.gov.au/The Conversation, CC BY-ND

Hepatitis

Australian-born children receive four shots of the hepatitis B vaccine, but some adults are advised to get vaccinations for hepatitis A or B. Those recommended to receive the hepatitis A vaccine are: travellers to hepatitis A endemic areas; people whose jobs put them at risk of acquiring hepatitis A including childcare workers and plumbers; men who have sex with men; injecting drug users; people with developmental disabilities; those with chronic liver disease, liver organ transplant recipients or those chronically infected with hepatitis B or hepatitis C.

Those recommended to get the hepatitis B vaccine are: people who live in a household with someone infected with hepatitis B; those having sexual contact with someone infected with hepatitis B; sex workers; men who have sex with men; injecting drug users; migrants from hepatitis B endemic countries; healthcare workers; Aboriginal and Torres Strait Islanders; and some others at high risk at their workplace or due to a medical condition.


Read more – Explainer: the A, B, C, D and E of hepatitis


Human papillomavirus

The human papillomavirus (HPV) vaccine protects against cervical, anal, head and neck cancers, as well as some others. It is available for boys and girls and delivered in high school, usually in year seven. There is benefit for older girls and women to be vaccinated, at least up to their mid-to-late 20s.

The elderly

With ageing comes a progressive decline in the immune system and a corresponding increase in risk of infections. Vaccination is the low-hanging fruit for healthy ageing. The elderly are advised to receive the influenza, pneumococcal and shingles vaccines.

Influenza and pneumonia are major preventable causes of illness and death in older people. The flu causes deaths in children and the elderly during severe seasons.

The most common cause of pneumonia is streptococcus pneumonia, which can be prevented with the pneumococcal vaccine. There are two types of pneumococcal vaccines: pneumococcal conjugate vaccine (PCV) and pneumococcal polysaccharide vaccine (PPV). Both protect against invasive pneumococcal disease (such as meningitis and the blood infection referred to as septicemia), and the conjugate vaccine is proven to reduce the risk of pneumonia.

The government funds influenza (annually) and pneumococcal vaccines for people aged 65 and over.

Vaccination is the low-hanging fruit for healthy ageing.
from shutterstock.com

Shingles is a reactivation of the chickenpox virus. It causes a high burden of disease in older people (who have had chickenpox before) and can lead to debilitating and chronic pain. The shingles vaccine is recommended for people aged 60 and over. The government funds it for people aged 70 to 79.


Read more – Explainer: how do you get shingles and who should be vaccinated against it?


Australian travellers

Travel is a major vector for transmission of infections around the world, and travellers are at high risk of preventable infections. Most epidemics of measles, for example, are imported through travel. People may be under-vaccinated for measles if they missed a dose in childhood.

Anyone travelling should discuss vaccines with their doctor. If unsure of measles vaccination status, vaccination is recommended. This will depend on where people are travelling, and may include vaccination for yellow fever, Japanese encephalitis, cholera, typhoid, hepatitis A or influenza.

Travellers who are visiting friends and relatives overseas often fail to take precautions such as vaccination and do not perceive themselves as being at risk. In fact, they are at higher risk of preventable infections because they may be staying in traditional communities rather than hotels, and can be exposed to risks such as contaminated water, food or mosquitoes.

Aboriginal Australians and Torres Strait Islanders

Indigenous Australians are at increased risk of infections and have access to funded vaccines against influenza (anyone over six months old) and pneumococcal disease (for infants, everyone over 50 years and those aged 15-49 with chronic diseases).

They are also advised to get hepatitis B vaccine if they haven’t already received it. Unfortunately, overall vaccine coverage for these groups is low – between 13% and 50%, representing a real lost opportunity.


Read more – Dr G. Yunupingu’s legacy: it’s time to get rid of chronic hepatitis B in Indigenous Australia


Migrants and refugees

Migrants and refugees are at risk of vaccine-preventable infections because they may be under-vaccinated and come from countries with a high incidence of infection. There is no systematic means for GPs to identify people at risk of under-vaccination, but the new Australian Immunisation Register will help if GPs can check the immunisation status of their patients.

The funding of catch-up vaccination has also been a major obstacle until now. In July 2017 the government announced free catch-up vaccinations for children aged 10-19 and for all newly arrived refugees. This covers any childhood vaccine on the National Immunisation Schedule that has been missed.

The ConversationWhile this does not cover all under-vaccinated refugees, it is a welcome development. If you are not newly arrived but a migrant or refugee, check with your doctor about catch-up vaccination.

C Raina MacIntyre, Professor of Infectious Diseases Epidemiology, Head of the School of Public Health and Community Medicine, UNSW and Rob Menzies, Senior Lecturer, UNSW

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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This may not be the ‘biggest flu season on record’, but it is a big one – here are some possible reasons

The Conversation

File 20170818 28163 14sfags
When the H3N2 strain dominates, we see bigger flu seasons and cases affecting the elderly more than the young. from shutterstock.com

Ian M. Mackay, The University of Queensland and Katherine Arden, The University of Queensland

This year, the number of laboratory-confirmed influenza (flu) virus infections began rising earlier than usual and hit historic highs in some Australian states. If you have been part of any gathering this winter, this is probably not news.

States in the south-east (central and southern Queensland, New South Wales, Victoria, Tasmania and South Australia) are more inflamed by flu than those in the north and west. For example, Queensland has seen more hospital admissions than in the last five years, mostly among an older population, while younger demographics more often test positive without needing hospitalisation.

https://datawrapper.dwcdn.net/WJNDI/2/

Meanwhile, flu numbers in New Zealand and elsewhere in the Pacific have not matched the same elevated levels. But is Australia really experiencing the biggest flu season on record in 2017, or are we just testing more and using better tools?

This is hard to answer for certain because the information we need is not usually reported until later and public databases only show the past five years. We can say for sure that 2017 is on track to be a historically big flu year.


Read more: Have you noticed Australia’s flu seasons seem to be getting worse? Here’s why


Really, a big flu season

Flu can be a nasty illness. Sometimes it’s deadly. Other times it can be mild. But even for cases that fall in the middle you may not be able to work for days, or you’ll have to look after ill children home from school, or visit the very sick who have been hospitalised.

Years ago, detection of influenza viruses mostly relied on slow, finicky methods such as testing for virus in artificial cell cultures. But, in Australia today, most laboratories use either sensitive tools to detect viral gene sequences in samples from the patient’s airway, or less sensitive but rapid dipstick methods, where a special strip is placed in a sample to detect viral proteins.

These tools have been in use since 2007 in the larger Australian laboratories, so it’s unlikely we are just seeing more positives in 2017. While newer versions of these tests are being rolled out this year, they are unlikely to detect more cases. Equally, it’s unlikely more people with suspected flu decided to change their behaviour in 2017 and get tested, compared to 2016, or the year before.

Flu can be a nasty illness and you may be off work for days. from shutterstock.com

As in all years, there are many people in the community with flu who don’t get tested. The proportion of people with flu who are tested likely remains roughly the same year to year.

State-wide flu reports provide reliable, laboratory-confirmed results. By looking at them, we can also be confident that “man flu” and severe common colds aren’t contributing to this specific and large increase in flu. We’re very likely seeing a truly huge flu season.

Why so bad this year?

Flu, caused by infection with an influenza virus, is mostly a disease with an epidemic peak during July and August in non-tropical countries. Flu viruses are broadly grouped into two types: Influenza-A and Influenza-B. Influenza-B viruses have two main sub-types while the Influenza-A viruses are more variable.

The Influenza-As you get each year are usually A/H3N2 (the main player so far this season) or A/H1N1, which lingers on from its 2009 “swine flu” pandemic. Multiple flu viruses circulate each year and serial infections with different strains in the same person in a single season are possible.

https://datawrapper.dwcdn.net/nglY2/3/

H3N2 has played a big role in the past five flu seasons. When it clearly dominates we tend to have bigger flu seasons and see cases affecting the elderly more than the young.

H3N2 is a more changeable beast than the other flu viruses. New variants can even emerge within a season, possibly replacing older variants as the season progresses. This may be happening this winter, driving the bigger-than-normal season, but we won’t know for certain until many more viruses are analysed.

Outside winter, flu viruses still spread among us. This year, in particular, we’re being encouraged to get vaccinated even during the peak of flu season. Vaccines are a safe way to decrease the risk that we or loved ones will get a full-blown case of the flu.

Yet Australian flu vaccination rates are low. Data are scant but vaccination rates have increased in adults and some at-risk groups, but remain lower than for childhood vaccines.


Read more: Disease risk increasing with unvaccinated Australian adults


The flu vaccine

Each season new flu vaccines are designed based on detailed characterisation of the flu viruses circulating in the previous season. But the viruses that end up dominating the next season may change in the meantime.

It is not clear whether that was a factor for this year’s high numbers in Australia this year or precisely what the vaccine uptake has been in 2017. Much of this detail will not be reported until after the epidemic ends. Some testing suggests this year’s vaccine is well matched to the circulating viruses.

The flu vaccine is not the most effective of vaccines, but it is safe and the only preventive option we have for now. Of those vaccinated, 10-60% become immune to flu virus.


Read more: Flu vaccine won’t definitely stop you from getting the flu, but it’s more important than you think


Future flu vaccines promise to account for the ever-changing nature of flu virus, reducing the current need for yearly vaccination. Until they are available, though, it remains really important to book an appointment with your vaccine provider and get a quick, safe vaccination, because we are unarguably in the midst of the biggest flu season Australia has seen in years.

The ConversationWe have both vaccines and drugs to help us prevent and minimise disease and the extra load on hospitals caused by flu. The young, elderly, those with underlying disease and Indigenous Australian people are most at risk of the worst outcomes and this is reflected by government-funded vaccination for these groups.

Ian M. Mackay, Adjunct assistant professor, The University of Queensland and Katherine Arden, Virologist, The University of Queensland

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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The number of new flu viruses is increasing, and could lead to a pandemic

The Conversation

C Raina MacIntyre, UNSW; Abrar Ahmad Chughtai, UNSW, and Chau Bui, UNSW

Influenza has affected humans for over 6,000 years, causing pandemics at regular intervals. During the 1918 Spanish flu, it was thought to be a bacteria, until an American physician Richard Shope identified the virus in 1931. The Conversation

So how is it this pathogen has managed to stay around for so long, and why haven’t we beaten it yet? The answer is that influenza is a virus that changes rapidly and regularly.

New flu vaccines are required every year due to these changes and mutations of the virus. While all flu viruses which infect humans are similar, a pandemic virus (which is easily transmitted between humans) is significant because humans have no immunity to it, and so are vulnerable to severe infection and death. Seasonal viruses which we see year after year were once pandemic strains, but humans have now been exposed to these viruses and have some background immunity to them.

We have found that the last decade has seen an acceleration in the number of flu strains infecting humans.

Why are there so many flu strains today?

Around 100 years ago the world experienced the Spanish flu pandemic, and it took another 39 years for a novel influenza virus to emerge. It took a decade after that for the next one. Since 2011, however, we have seen seven novel and variant strains emerge. This is a very large increase compared to the past.

The reasons for this increase are unknown, but there could be many. One reason could be better diagnostics and testing; another could be changes in poultry farming and animal management practices, since influenza is a virus that affects humans, birds and many animal species; as well as changes in climate, urbanisation and other ecological influences.

But none of these factors have changed at the same rate as the emergence of new viruses has escalated. This warrants new research to unpack the relative contributions of all the different possible factors.

Another change is advances in genetic engineering tools, which make it possible to edit the genome of any living organism, including viruses. The possibility of a lab accident or deliberate release of engineered flu viruses is real. Experiments to engineer influenza viruses have been published since 2011, and remain controversial for the possible risk, compared to the relative possible benefit.

With so many more novel influenza viruses emerging and circulating, the probability of genetic mutation and emergence of a new pandemic strain is higher today than any time in the past. It’s a matter of when, not if.

What can we do to prevent a pandemic?

There’s actually already a lot being done to plan for and prevent another flu pandemic. This is both in terms of pharmaceutical drugs and vaccines, and non-pharmaceutical interventions like personal protective equipment, quarantine, border control and banning of mass gatherings in the event of an outbreak.

National pandemic plans outline interventions and the best sequence of different interventions, as well as prioritisation of these interventions. Most countries also conduct pandemic hypotheticals to test their systems and responses. But the best laid plans do not account for every possibility, and we usually encounter the unexpected.

For example, during the 2009 swine flu pandemic, the pandemic phases outlined in the Australian pandemic plan were revised to better fit the emerging situation. This highlights the need to be able to rapidly respond to changing circumstances and change strategies when required.

What about vaccines?

Vaccination is the most talked about strategy but producing a matched vaccine takes three to six months at a minimum. The pandemic would be expected to peak within about two months, so vaccines can’t be relied on until after the peak of the pandemic. Instead, we need to use antiviral medications, social distancing measures, personal protective equipment such as masks and gloves, isolation and quarantine to contain the pandemic.

Influenza vaccines are specific to strains of flu, and can be used for humans, birds or animals. However, they will only work against the specific strains the vaccine was designed for. There are no vaccines for many of the novel strains emerging all over the world.

It’s almost impossible to anticipate which specific virus will cause the next pandemic. At best we can prepare pre-pandemic vaccines which require an educated guess as to which virus may mutate into a pandemic strain, and make a vaccine against that.

A strain-specific pandemic planning strategy like this is not the best approach, as illustrated by the swine flu pandemic in 2009. From 2005 until 2009, the avian flu virus H5N1 (flu viruses are defined and named by proteins on their surface, haemagglutinin – H, and neuraminidase – N) was the major cause of bird flu, so the world focused heavily on preparing for a H5N1 pandemic and developing a H5 pre-pandemic vaccine.

However, the virus that caused the 2009 pandemic was H1N1, a completely different virus, so the pre-pandemic vaccines were no use.

A better approach is to try to prevent the emergence of new virus strains in birds and animals, and mitigate the risks once they emerge. This involves control strategies in both animal and human health sectors, surveillance and prevention efforts.

A targeted approach in global hotspots such as China, the source of the H7N9 influenza virus, and Egypt, which is experiencing a surge in H5N1 influenza, will also help.

Hotspots are generally where humans and livestock mix in close proximity, such as backyard poultry farms and live bird markets. Asia has historically been such a site. However, we sometimes see unusual outbreaks such as the bird flu outbreak in turkey farms in the USA in 2015.

Culling of birds is a commonly used method to control the risk once infection is detected. As are measures such as regulation of live bird markets and of the poultry and livestock industries. Excellent surveillance, rapid intelligence and picking up potential pandemics as they arise can make all the difference. We probably had a near miss pandemic strain arising in Indonesia in 2006, but the remote location and early detection mitigated the risk.

C Raina MacIntyre, Professor of Infectious Diseases Epidemiology, Head of the School of Public Health and Community Medicine, UNSW; Abrar Ahmad Chughtai, Epidemiologist, UNSW, and Chau Bui, PhD candidate, UNSW

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Thinking about getting the 2016 flu vaccine? Here’s what you need to know

The Conversation

C Raina MacIntyre, UNSW Australia and Aye Moa, UNSW Australia

Up to one in ten adults and three in ten children are infected with influenza each year.

The vaccine we have used for decades, the trivalent vaccine (TIV), protects against three strains of flu. But in 2016, for the first time, the publicly funded vaccine program will offer the quadrivalent flu vaccine (QIV), which protects against four instead of three strains of flu.

The seasonal influenza vaccination is now available at GP clinics and pharmacies. For those not eligible for the free vaccine, it will cost around A$9$15 for the TIV and A$12$25 for the QIV, plus the cost of the consultation if your GP doesn’t bulk bill.

So, what strains do these vaccines protect against? Who should be vaccinated? And, if you’re paying, what additional benefit does the new QIV have?

What is influenza?

Influenza virus is a serious infection, which causes 1,500 to 3,500 deaths in Australia each year. Death occurs from direct viral effects (such as viral pneumonia) or from complications such as bacterial pneumonia and other secondary bacterial infections.

In people with underlying coronary artery disease, influenza may also precipitate heart attacks, which flu vaccine may prevent.

The two major types of influenza infection are influenza A and B; the A strain causes more severe disease than B. Influenza B, however, may be under-reported and causes more severe illness in children and young adults.

The Influenza A virus has much greater genetic diversity than B, probably because it has several non-human animal hosts such as birds, pigs and horses. This sets the scene for genetic mixing between human and animal strains, which accounts for the diversity of the virus, along with constant changes each year as it tries to evade its hosts’ immune responses.

The flu vax may also protect against heart attacks in those with underlying disease. Government of Alberta/Flickr, CC BY-NC-ND

Minor changes (drift) account for new viruses circulating each season, whereas major changes (shift) result in new pandemic strains, to which humans have little or no pre-existing immunity. Influenza B, in contrast, has only two major lineages and much less genetic diversity; seals are the only animal host.

Pandemic strains of the past, once established in human populations, become seasonal strains and tend to cycle over the years, with different strains dominating each year.

Seasonal vaccination

The influenza vaccine is formulated annually because seasonal flu viruses undergo continuous genetic mutation and the vaccine needs to match the major circulating strains. A vaccine from a previous year will generally not confer much protection the following year.

The holy grail of influenza vaccines is a universal vaccine, a one-off shot that would give lifelong protection. Such vaccines are being developed and may not be far off.

Until that time, every year The World Health Organisation studies the circulating viruses and decides which strains will be covered in that year’s flu vaccine. This process occurs separately for the southern and northern hemispheres. It’s usually successful, but a mismatch between the circulating flu virus and the vaccine may sometimes occur.

While live flu vaccines are available in other countries, only the inactivated vaccine is available in Australia. This cannot cause influenza, as it does not contain live virus.

The trivalent vaccine (TIV) contains protection against three strains: two of influenza A and one of influenza B. But there are two major circulating lineages of influenza B, and recent research shows that a TIV B vaccine mismatch occurs approximately 25% of the time.

The quadrivalent (QIV) strain protects against the second B lineage.

Different flu strains dominate each year. Claus Rebler/Flickr, CC BY-SA

Several different companies manufacture TIV and QIV. The vaccines are safe and effective, although one brand, Fluvax, is not approved for children under the age of five years because of an increased risk of febrile seizures.

The 2016 Australian trivalent inactivated influenza vaccine protects against:

  • A (H1N1): an A/California/7/2009 (H1N1)-like virus
  • A (H3N2): an A/Hong Kong/4801/2014 (H3N2)-like virus (H3N2 is generally the most severe form of influenza A)
  • B: a B/Brisbane/60/2008-like virus.

The quadrivalent inactivated influenza vaccine (QIV) protects against the three strains about and an additional B lineage:

  • B/Phuket/3073/2013-like virus.

Should I get vaccinated?

Australia’s national immunisation program recommends and funds free flu vaccinations for:

  • people aged 65 years and older
  • Aboriginal and Torres Strait Islander people aged 15 years or older
  • pregnant women
  • anyone over six months of age with a medical condition such as heart disease, respiratory disease, diabetes, kidney disease, asthma, immunosuppression and chronic neurological conditions
  • children on long-term aspirin therapy.

Pneumonia is a common complication of influenza, so people with risk factors are also recommended for pneumococcal vaccine.

Those at risk of complications from the flu are eligible for the free vaccine. Direct Relief/Flickr, CC BY-NC-ND

About 70% of people over 65 are vaccinated, but only 30-50% of people aged under 65 years with risk factors get vaccinated each year.

Australians who don’t fall within one of these at-risk groups may choose to get vaccinated to protect themselves, family members, colleagues/patients or friends.

The 2016 flu season

Flu seasons typically cycle between mild and severe epidemic years.

The 2015 Australian flu season was dominated by two lineages of influenza B (62% of cases), the highest influenza B season since 2008. Children five to nine years old, adults aged 35 to 44 and the elderly aged over 85 were most affected.

The major influenza A viruses in circulation last year were influenza A (H1N1) pdm09 and, to a lesser degree, influenza A (H3N2).

The effectiveness of the flu vaccine varies each year. Both TIV and QIV can protect well if the circulating strains are similar to the vaccine strains.

In the United States, the Centers for Disease Control and Prevention (CDC) reported that vaccine effectiveness for the 2015-2016 flu season was about 60%, and the vaccine strains a good match for the season.

Any person recommended for vaccination on the National Immunisation Program schedule should get vaccinated as early as possible. They will be able to benefit from the QIV, which confers greater protection by eliminating the possibility of B lineage mismatch.

But if paying for the vaccine privately and cost is an issue, the TIV is more affordable and will still confer good protection.


Further reading: Health Check: when is ‘the flu’ really a cold?

The ConversationC Raina MacIntyre, Professor of Infectious Diseases Epidemiology, Head of the School of Public Health and Community Medicine, UNSW Australia and Aye Moa, PhD candidate, UNSW Australia

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

 

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Explainer: how viruses can fool the immune system

The Conversation

Kim Jacobson, Monash University

The immune system protects us from the constant onslaught of viruses, bacteria and other types of pathogens we encounter throughout life. It also remembers past infections so it can fight them off more easily the next time we encounter them.

But the immune system can sometimes misbehave. It can start attacking its own proteins, rather than the infection, causing autoimmunity. Or, it can effectively respond to one variant of a virus, but then is unable to stop another variant of the virus. This is termed the original antigenic sin (OAS).

OAS occurs when the initial successful immune response blocks an effective response when the person is next exposed to the virus. This can have potentially devastating consequences for illnesses such as the mosquito-borne dengue.

There are around 400 million dengue infections worldwide each year and no vaccine is available. Reinfection of someone who has been exposed to dengue previously can result in life-threatening hemorrhagic fever.

OAS is also thought to limit our immune responses to the highly variable influenza virus, increasing the chance of pandemics.

To understand why OAS occurs, we need to go back to basics about how immunity is formed.

The race begins

When a virus enters the body, a race begins between responding immune cells and the infecting pathogen. The pathogen replicates and finds a target cell or organ that will allow it to thrive.

So, the effectiveness of a response depends on the immune system winning the race to clear the pathogen before it causes irreversible damage to the body.

Immune cells called “B cells” make antibodies. A pathogen such as a virus is a large molecule with different components, called antigens. When a B cell recognises an antigen, it is activated and interacts with other immune cells to receive directions.

Quality control

B cells then set out on two main paths. Some of the cells begin to make an antibody early in the response. But this antibody is often not of sufficient quality to rid the body of the infection.

The B cells that choose the alternate pathway go through a process that improves the quality of the antibody. This strengthens the binding between antibody and antigen. Antibodies are also grouped depending on the way they help eliminate the pathogen.

Some groups are better at clearing viruses and other pathogens. So, the antibody group that is tailored to be most effective at clearing the type of infection comes to dominate the response over this period.

Although the increase in quality of antibody can take weeks, there are two critical benefits. It means the pathogen is cleared. And high-quality “memory” cells remain to provide us with immunity to future infections.

Memory cells

Immune memory cells consist of long-lived plasma cells and memory B cells. Long-lived plasma cells live in the bone marrow and can continuously pump out high-quality antibody, providing a first wave of protection when we’re reinfected with a virus.

This is the same type of antibody that is transferred from mother to a breastfed baby, providing passive immunity against pathogens the mother has previously been infected with. But this level of antibody may not be enough to clear the infection.

This is where memory cells step in. Because memory cells have already undergone quality improvement, they can respond quickly after reinfection to produce a large number of plasma cells secreting high-quality antibody.

Therefore, memory cells can clear the infection much more rapidly than the initial infection. This means the pathogen doesn’t have time to damage the body.

When the quality improvement process fails

The quality improvement process that allows B cells to bind and clear the pathogen more effectively is highly selective to the dominating antigen.

In most responses to infection, this is critical to clear the infection. But in the case of some pathogens, such as dengue, the virus may have variant strains that can fool the immune memory response.

Dengue virus has four major variant serotypes. Within each major variant, one antigen dominates and is targeted by the immune system.

Infection by variant A results in extremely selective targeting towards antigen A. If the body is reinfected with the same variant (A), it can effectively clear the virus.

However, after reinfection by a second variant (in which antigen B dominates), immune memory cells recognise the virus, but they make antibody specific for antigen A, rather than the second variant, in which antigen B is now dominating.

So, antibody is being made but is unable to bind and eliminate the virus. To make matter worse, it appears that any new immune response to antigen B is inhibited by the memory response, although the reasons why this occurs are unclear.

Influenza is a highly variable virus, and these variations each season are why we require yearly vaccinations.

But the role of OAS in limiting our ability to respond to different variants of influenza is still highly controversial. Almost 60 years after OAS was proposed to describe the response to influenza infections, it is still a source of much current research.

How can we avoid OAS?

We need to train our immune system to be more flexible and produce antibodies that can adapt when viruses try to evade the immune system.

To this end, researchers are designing vaccines to respond to multiple variants of pathogens. This has shown promising results and may be the way forward to overcome OAS for potentially life-threatening viruses such as dengue.

The ConversationKim Jacobson is Senior Research Fellow at Monash University.

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.


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