Tag Archives: immunisation

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

The Conversation

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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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Please don’t do your own research on immunisation; you’ll get it wrong

The Conversation

Michael Vagg, Deakin University

Pauline Hanson has become the latest politician to flirt with the fringe view of immunisation denial. Of course, like all thoroughly modern anti-vaxxers, she claims to be about choice and empowerment rather than denial of the overwhelming scientific consensus. The Conversation

Of all the weasel words immunisation deniers use, I get most infuriated by the “do your own research” trope.

You don’t need to. Unless you’re a senior research scientist with your own lab, a posse of postdocs and serious wad of cash, we don’t need your help.

What Senator Hanson appears to mean is that she wants average people who find misinformation on the internet to be allowed to disagree with decades of rigorous, serious scientific effort. Unlike so many of my medical colleagues, I make an effort to keep up with goings-on in the anti-vax movement so I am grimly aware of the depths of hubris and folly that inform the “research” you so easily find when you innocently Google for vaccine information. The average person with high-school science knowledge and healthy faith in human decency has no chance.

Someone who has limited time and attention would not possibly bother to wade through the byzantine details of how Andrew Wakefield’s fraud was uncovered and the scurrilous ongoing attempts to smear Brian Deer, the investigative journalist who brought it to light.

Only a dogged student of human nature would have the stomach to watch videos featuring the pseudoscientific ramblings of the supposed intellectual leaders of this wretched movement. Yet many of us have done this for you. Trust me, there is no wisdom or learning in these cranks.

Only the real enthusiasts would have watched with bemusement last month as the Chiropractors’ Association of Australia (CAA) had a public spat on their own Facebook page with the AV-sN, Australia’s leading anti-vax organisation. CAA finally got around to demanding the removal of a link from AV-sN website endorsing their chiropractic philosophy of opposing immunisation. Their public statement read in part:

It has come to our attention that the Australian Vaccination-sceptics Network contains a link to the CAA National website. We have requested that they remove this link to our website as a matter of urgency.

The Chiropractors’ Association of Australia (CAA) does not support the views promoted by the Australian Vaccination-sceptics Network.

The former president of the anti-vaxxers then further embarrassed CAA by turning up in the comment section and lamenting:

More and more chiropractors are speaking out against their governing body trying to tell them that they must ignore basic chiropractic philosophy of the power that made the body heals the body in order to gain acceptance from mainstream medicine. When will the CAA understand that mainstream medicine’s only concern is to maintain their own authoritarian monopoly and destroy any and all competitors?

I’ve previously documented how CAA has been providing anti-vax speakers at official learning activities approved for professional development by their regulator, but you won’t find this information on the front page of your Google search. As recently as 2015, the CAA National Conference featured several speakers with links to the antivax movement. But again, the background briefing needed to appreciate the importance of this is not available to any but the most hardcore anti-vax-watchers.

I could go on and on in this vein, but I’ll spare you. Suffice to say that everywhere you get suspicion and hostility about immunisation you also get shoddy thinking and misrepresentation of plain facts. You get routine denial of reality and genuinely unhinged discourse. Science becomes The Enemy. Ideology trumps evidence.

There is no worthwhile political debate to be had here. Giving such deformed pseudoscience any media oxygen at all is reckless. It is unworthy of a serious aspirant to political power. By parroting the coded messages of the anti-vax movement, and encouraging hesitant parents to “do their own research” Senator Hanson is enabling an unspeakable industry to thrive. Make no mistake, there are hucksters both big and small raking in money by manufacturing hostility towards one of the greatest gifts our benighted species has managed to give itself.

All these cretins want is the chance to get unwary, perhaps vulnerable parents in front of their finely tuned propaganda.

What Senator Hanson has just done is give them a flood of fresh eyeballs to sell to.

Michael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Deakin University

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

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Are vaccines making viruses more dangerous?

The Conversation

Dave Hawkes, University of Melbourne

Despite the near-universal acceptance of the benefits of vaccination, some people still worry about risks associated with their use. Luckily, scientists are vigilant about identifying possible risks, so they can be addressed before problems emerge.

Still, people sometimes forget that science is the process by which we arrive at solutions. And they worry about incremental scientific steps that often expose weakness in these solutions.

A recent study published in the journal PLOS Biology, for instance, was presented by some media as claiming that certain vaccines make viruses more dangerous. The research showed chickens treated with its vaccine are more likely to spread a highly virulent strain of Marek’s disease virus, a condition that affects poultry.

The reason was simple: the vaccine used in the study targets Marek’s disease, not the virus that causes it. These types of vaccines are known as “leaky vaccines” because they don’t affect the ability of the virus to reproduce and spread to others; they simply prevent the virus from causing disease.

Marek’s disease vaccines use a non-disease-causing virus to infect cells. This preventive infection stops tumour formation and death when those cells are infected by the Marek’s disease virus.

But the virus can replicate and still produce more virus particle, which can infect other chickens. All Marek’s disease vaccines, since their introduction in the 1970s, have been leaky; they allow chickens to carry and spread the virus without getting the disease.

‘Imperfect-vaccine hypothesis’

The effect of leaky vaccines on how disease spreads is explained by the “imperfect-vaccine hypothesis”. It holds that, without vaccination, a very virulent virus can get into a population and kill infected hosts (people or animals) very quickly – before they have a chance to spread it. This means that the virus will die out very quickly too, as all potential hosts will be dead or immune to it.

A leaky vaccine can prevent the very virulent virus from killing the host, but doesn’t stop that host from spreading the virus to others. This means that a very virulent virus can survive for long periods in the vaccinated hosts. And it can continue to spread in this time, making it less likely to die out.

The PLOS Biology study showed chickens vaccinated against Marek’s disease were more likely to spread the disease to other chickens, than unvaccinated chickens were. The unvaccinated chickens all died in less than ten days – before they could spread the virus.

The vaccinated chickens, on the other hand, were protected from the disease so were able to spread the virus to other (unvaccinated) chickens for weeks and weeks. And they made those chickens immune to the virus in the process.

Marek’s disease, which affects poultry, has a ‘leaky’ vaccine’. David Goehring/Flickr, CC BY-SA

One of the reasons the researchers looked at Marek’s disease in chickens is because it has been getting progressively deadlier. Originally, the disease occurred mainly in older chickens and caused paralysis. But an acute form of the disease emerged in the 1950s and has since become the dominant form. This rather virulent version can kill up to 100% of unvaccinated birds.

Leaky but not sinking

But what does all this mean for the future of vaccination?

Well, the first thing to note is that in this study the vaccinated chickens always had the best outcome. In one experiment, only three out of 50 unvaccinated chickens survived the disease, while vaccination protected the majority of chickens (46 out of 50 survived).

The authors also noted that vaccination has been very effective in preventing deaths in chickens due to Marek’s disease. They said their study didn’t indicate whether vaccination played any role in the development of the serious form of Marek’s disease.

Vaccines prevent disease, even if they’re leaky. But it’s important to note there are currently no vaccines against viruses that infect humans that are leaky. Current human vaccines mimic the body’s own response to viruses.

But yet-to-be-developed vaccines for diseases such as HIV, Ebola or malaria, where humans have been unable to mount an effective natural defence, are likely to be leaky. And even imperfect vaccines for these illnesses would be an enormous step forward.

The possible effect of “leaky vaccines” on how viruses spread is an interesting new observation. But there are a number of other ways by which viruses can change in response to vaccination.

An arms race

One response of viruses to vaccines involves the evolution of viral proteins that allow them to escape the vaccine. This is known as “epitope evolution” and it’s the reason flu vaccines change each year.

Even if a vaccine is effective in preventing a particular strain of virus, other strains may take its place. This was a concern when the human papillomavirus (HPV) vaccine was introduced nearly ten years ago. But researchers have investigated whether any HPV types not in the vaccine have become more common since the vaccine was introduced and there’s no evidence this is happening.

The interaction between viruses and their targets can change over time. In the case of Marek’s disease, the infection has become progressively deadlier. Increased use of broiler chickens, lack of genetic diversity in flocks and high-density rearing may all have played a role in the changes seen in the disease.

The benefits of vaccination far outweigh its risks. And it is research like this that helps medical researchers actively identify possible dangers so we can safely continue to avoid the diseases that terrified our parents’ generation.

The ConversationDave Hawkes is Honorary Fellow at Department of Pharmacology and Therapeutics at University of Melbourne

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

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Immunisation, the media and the amplification of irrational anxiety

The Conversation

Brian McNair, Queensland University of Technology

The government’s ‘no jab, no pay’ policy, which will restrict childcare benefits for those parents who refuse to have their kids immunised, may seem harsh to some. Most parents, however, will see the wisdom of a policy which puts the collective welfare of all children above the conscientious objections of a few parents.

The rate of non-immunisation of children has risen from 1% to 2% in a decade, noted Tony Abbott at a Sunday morning press conference announcing the new policy. 40,000 children are not immunised in Australia, he added, and rates of some very avoidable but potentially lethal children’s diseases such as measles and whooping cough have gone up.

That 2% put at risk the other 98%, and using the tax and benefits system to send that message is tough, but justified.

In the United States and the UK, too, immunisation rates have fallen over recent years, and diseases which once plagued our children, and were then all but wiped out by immunisation programs, have returned in significant numbers. So what has been going on? Why are so many parents refusing to take advantage of a preventive medical technology which has saved literally millions of children’s lives across the world?

One answer, if not the only one – some have deep religious objections, for example – is the news media, and their role in what we might call the amplification of irrational anxiety.

A small but significant minority of parents have come to believe, in all sincerity (and no-one doubts that they have the best interests of their children at heart) that immunisation is dangerous, and certainly riskier than the risks associated with not having their kids vaccinated.

Even though there is no solid evidence to support that belief, and plenty of evidence to support the benefits of immunisation, some parents are so anxious that they will put their own children, and more importantly, other people’s children, at heightened risk of exposure to a preventable disease which could cause disability and even death.

So where have these anxieties come from?

Back in 2004, an English doctor by the name of Andrew Wakefield published research claiming to demonstrate a link between the MMR triple vaccine (to immunise children against mumps, measles and rubella) and the onset of autism. As followers of the story will know, Wakefield’s work was subsequently discredited, and he himself struck off the medical register in the UK for his unethical research methods.

Before that happened, however, the alleged risks of MMR became a major news story in the UK and all over the world. At that time, a decade ago, the global incidence of autism had risen dramatically. Between 1996 and 2007 in the United States, for example, the reported incidence of autism rose from 0.8 per 1,000 to 5.2 – an increase of some 600%.

Similar increases were recorded in many other countries. In Australia, the first survey of the prevalence of autism did not take place until 2006 so historical data are lacking. In 2014, however, the Australian Bureau of Statistics found a 79% increase in diagnoses between 2009 and 2012. A NSW parliament report of 2013 noted that:

… the growing number of children diagnosed with Autism Spectrum Disorder (ASD) is an issue of concern both in Australia and overseas.

This does not mean that the actual prevalence of autism has risen, though. Rather, the public awareness of autism has risen, through movies such as Rain Man and the explosion of media visibility around the condition seen since the 1990s. Documentaries were made about autistic ‘savants’, and families where parents struggled to cope with autistic children. The Curious Incident of the Dog in the Night Time became a global publishing phenomenon, and an entire sub-genre of ‘autism lit’ emerged.

Many people, children and adults, who might hitherto have been described as ‘different’ or ‘eccentric’, or even just ‘shy’, were labelled with Asperger’s Syndrome, or some other condition on the autistic spectrum.

Through a heightened media visibility, parents, medical professionals, teachers and others involved with children were sensitised to a condition which until recently was little known and poorly understood. In other words, autism has always existed, but only recently has it been recognised and given a name. As a result, its recorded incidence has risen dramatically, not because more children are acquiring autism from one cause or another, but because more of those born with it – and autism is often a genetic condition that runs in families and mainly affects males – are being identified.

This is a positive development, because autism is very real, and heightened public awareness has led to support services being put in place for people with autism where there had been none.

Notwithstanding this context, one cannot blame parents for becoming more anxious about the causes of autism, and many quite plausible, if never substantiated, theories have circulated. Wakefield’s research, when it was published in 2004, spoke directly to that anxiety, and his hypothesis – that autism was ‘caused’ by immunisation – seemed credible to many.

In the UK, where the scare was centred, and Wakefield’s work taken very seriously by most of the media, hundreds of thousands of parents withdrew their children from the MMR program. Then-prime minister Tony Blair was asked by journalists to reveal if his baby son Leo had been vaccinated or not. He refused to answer on privacy grounds, while making clear his own absolute confidence in the safety of the vaccine.

Despite such reassurances, and the widespread scepticism which greeted Wakefield’s research amongst his medical peers from the outset, the impact of the scare was very real. Rates of immunisation fell, while the incidence of measles and other preventable diseases began to rise. Ill-founded anxiety about the dangers of immunisation ended up having very real consequences on public health.

Years after Wakefield’s work had been discredited by his peers, his theories on MMR and autism have continued to influence parents all over the world. And where he has had influence, so the incidence of the diseases targeted by the MMR vaccine have risen.

In February this year, the Sunday Times reported on the anti-immunisation advocacy of US group Generation Rescue, who were reported to “seek inspiration” from Wakefield, who now lives and works in that country. The result of this campaign:

… say experts, has been to plunge America into the first national debate since the 1970s about the safety and necessity of vaccines — and led to the return of measles, a highly contagious childhood disease judged extinct by the US government’s Centers for Disease Control (CDC) 15 years ago.

In the US, vaccination rates had fallen by 3%, amid what the article called “a mounting sense of panic”. As in the UK a decade previously, erroneous health information spread through a variety of media channels had provoked a health crisis with strong political reverberations.

Politicians faced with anxious parents were encouraged to comment and pronounce on the vaccination ‘issue’, even when ignorant of the science. Republican contenders for the 2016 presidential race – Chris Christie and Rand Paul – both declared their approval of parental exemptions from MMR vaccination.

Rigorous research into media coverage of autism and its causes has not been done in Australia, and we cannot assume that all of those ‘conscientious objectors’ to immunisation are directly influenced by the Wakefield hypothesis. But his work, and the way it was reported a decade ago and since, undoubtedly contributed to a climate of fear around the risks of vaccination, irrational in so far as it lacks foundation in scientifically validated evidence.

The government is therefore right to take strong action against parents whose irrational fears knowingly put other children at risk. It is an example of firm government in the face of myth and unreason, and should be supported by all who care about the health of our kids.

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


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