Denialism should not be confused with modern scientific skepticism, which is the challenging of beliefs that are unscientific, irrational or based on insufficient evidence. Instead of denying facts, modern skeptics test claims by analysing whether they are supported by adequate empirical evidence. Denialism is the a priorirejection of ideas without objective consideration.
The philosophical skepticism of the Academic Skeptics and Pyrrhonists in Classical Greece (which was quite different to modern skepticism) consisted of doubting whether there can be any knowledge or facts at all, rather than denying particular facts.
Science denialism is the rejection of basic facts and concepts that are undisputed, well-supported parts of the scientific consensus on a subject, in favour of radical and controversial opinions of an unscientific nature. For example, the term climate change denialist is applied to people who argue against the scientific consensus that the global warming of planet Earth is a real and occurring event primarily caused by human activity.
The term evolution denialist or ‘creationist’ is applied to people who argue against the fact that life on Earth has evolved from earlier forms, instead of having been created by a supernatural being in its current form.
The motivations and causes of denialism include irrationality, religion and self-interest (political, economic or financial), beliefs in conspiracy theories or even defence mechanisms meant to protect the psyche of the denialist against mentally disturbing facts and ideas.
Researchers have found a promising way of kicking the AIDS virus out of its hiding place in infected cells, potentially removing the main obstacle to curing HIV.
While antiretroviral treatment successfully suppresses HIV replication in an infected person, it can’t completely remove the virus. This is due to the virus’ ability to integrate itself into the DNA of cells, where it can lie dormant and invisible to the body’s immune system for years.
These so-called “reservoirs” of what is known as “latent virus” are the primary barrier to an HIV cure. Recent research has focused on a “shock and kill” method, to shock the dormant virus out of its comfortable place in the reservoir. When the virus is active, it becomes a visible target to kill.
Previous attempts with agents called histone deacetylase (HDAC) inhibitors have shown inconsistent results. HDACs, that enable a virus to coil tightly around a cell’s DNA, are the primary reason for its successful ability to hide undetected.
If an HDAC inhibitor is potent enough, it could stimulate the unravelling and activation of the virus. Research published today in PLOS Pathogens shows the HDAC inhibitor, romidepsin – a drug currently being used to treat cancer – to be the most potent, and thus successful, inhibitor trialled so far.
Six patients, who had been on antiretroviral treatment for around 10 years, each received three transfusions of romidepsin. The dormant HIV was activated in five of the participants, making it a detectable target for elimination.
University of Melbourne Professor and Director of the Doherty Institute, Sharon Lewin, said the results were promising.
“It is an interesting study because it shows the effects of a more potent drug, which can activate or kick the virus out of hiding,” she said.
Researchers also found romidepsin coaxed the virus out of its reservoir without suppressing the body’s broader immune response.
“There’s been some concern that these drugs will suppress an immune response to the virus, and they looked pretty comprehensively to show that there was no suppression of immune function, so that was encouraging as well,” said Professor Lewin, who was not involved in the study.
Dr Kersten Koelsch, who was involved in the study, explained there had been concerns the HDAC inhibitors might negatively affect T cell responses, which play an important part in fighting infection.
“We know that the HIV reservoir needs to be controlled to some extent by T cell responses,” said Dr Koelsch, who is a senior lecturer at UNSW Australia’s Kirby Institute. “So if you had a weak T cell response after an intervention, that would be counterproductive. But it appears that this is not the case with these HDAC inhibitors.”
But Dr Koelsch also stressed that although the results were positive, researchers were by no means close to a HIV cure.
“Unless a miracle happens, there’s not going to be a cure for HIV for at least 10 or even 20 years,” he said.
“Small studies like this can be very informative for the next study which can then build upon it, and the next study will then be another piece in the puzzle that will be important to design the study afterwards.”
He said romidepsin was a “promising agent to check in future studies in combination with immunotherapies or vaccines.”
This will indeed be the next phase of the two-part trial, which will use a combined therapy of romidepsin with a HIV vaccine to kill the infected cells.
“Combination studies are of highest interest now. We need to know whether the combination of activation of the virus with boosting the immune system will actually clear the infected cell. That’s really what we’re after now,“ said Professor Lewin.
Senior Research Officer at the Burnet Institute, Lachlan Gray said the latest research was extremely promising. But he added there were limitations to current HIV research as it focused only on eliminatig the viral reservoir in the blood.
“Tackling the blood reservoir has been the major focus of cure research to this point, predominantly because it is the major HIV reservoir. Importantly, this research sets the scene for efforts focused on non-blood reservoirs such as the gut, and brain” said Dr Gray, who researches HIV replication in brain cells.
“To completely eradicate HIV from the infected individual, that is, where there’s a complete elimination of every HIV infected cell in the body, we need to target all reservoirs, not just the predominant blood reservoir.”
“I think we’re making inroads, and the more research, the more information gathered from important studies such as this, the closer we get to the end goal, which is curing HIV,” he said.
The news on the current measles outbreak contains plenty of reminders that measles causes brain damage, pneumonia, hearing loss and death. A few lone voices have spoken up to say measles isn’t that serious, including an Arizona doctor who said it’s “really just a fever and a rash” – and soon found himself under investigation by his state’s medical board.
Back in the 1960s, it wasn’t controversial to call measles benign. Though the disease killed about 400-500 Americans a year, it was considered a normal part of childhood. It was so common, in fact, that to this day, people born in the pre-measles vaccine era are considered immune. But the introduction of the measles vaccine, and efforts to promote it, fundamentally changed things. In the five decades since we’ve been immunizing against it, measles has become increasingly known as a deadly killer.
This transformation in perception, from relatively benign to a serious disease, isn’t unique to measles. As I have discovered in my research, it’s a pattern that’s been repeated over and over again in the modern history of immunization. This is not to say that measles is now considered a mild infection, or to suggest that risk from the virus, or other vaccine-preventable diseases, is overestimated. The point I want to argue is that the introduction of a vaccine reframes our perception of the disease it prevents.
Vaccines change our perception of risk
How does this happen? New vaccines simultaneously drive down the number of people getting the disease and increase our awareness of the risks of the disease.
Vaccines shine a spotlight on their target infections and, in time, those infections — no matter how “common” or relatively unimportant they may have seemed before — become known for their rare and serious complications and defined by the urgency of their prevention.
This certainly happened to measles, whose first vaccine was uneventfully released in 1963.
At the time, many parents saw measles as a common and relatively harmless part of childhood – even though it infected three to four million people a year and caused roughly 48,000 hospitalizations annually. Many doctors felt as parents did, especially when comparing measles to such worrisome disease threats as smallpox and polio. Even the head of the Centers for Disease Control described measles as a disease “of only mild severity” which caused “infrequent complications.”
But the very development of the vaccine focused new scientific attention on the disease. Within a few years, scientists had compared measles to polio — the previous decade’s public health priority — and found it a much more serious threat to children’s health. Inspired by this finding, and frustrated by the public’s lack of enthusiasm for the vaccine, federal health officials launched a national campaign to publicize measles’ dangers.
The campaign officially spread the word, for the first time, that measles was “a serious disease that sometimes causes pneumonia, deafness, encephalitis and even death.” Public figures ranging from the Surgeon General to Ann Landers announced that measles could leave children blind, deaf and mentally impaired. And the campaign employed a poster child — disabled ten-year-old Kim Fisher — to illustrate the idea that measles immunization was necessary because “one death, one brain-damaged child, or even one child who needs hospitalization is one too many,” as one campaign supporter put it.
A new picture of measles emerges
As the campaign wore on, scientists continued to study the disease more closely than ever. Doctors began to report measles cases to health departments at unprecedented rates. And together, doctors and scientists began to pay more attention to the disease’s risks than even before. As a result, a new picture of the disease began to form: it appeared to cause more deaths than previously thought, brain damage in even mild cases, even harm to fetuses.
As the public continued to respond to the national campaign with “general apathy,” however, health officials redoubled their efforts to publicize measles’ “dramatic aspects,” and states began passing laws requiring the vaccine for schoolchildren. Within just over a decade, the country saw an all-time low of measles cases — and the disease had solidly acquired its new reputation as a deadly infection worthy of prevention at any cost.
We used to think mumps and chickenpox were ‘mild’ too
In the decades that followed the introduction of the measles vaccine, vaccine makers and health officials duplicated this approach with one new vaccine after another.
Mumps, often the butt of jokes in its pre-vaccine days, was no laughing matter within a decade of its vaccine’s introduction in 1967. Hepatitis B was considered an obscure infection of little import to most Americans when its vaccine first came out in 1981, but soon after it evolved into a “cousin” of AIDS known for lurking in nail salons, piercing parlors and playgrounds.
Since the development of the chickenpox vaccine in the 1990s, the virus has been transformed in the public imagination from an innocuous if uncomfortable rite of childhood to a highly contagious infection that can cause pneumonia, sepsis and sometimes death. And in just the last decade, human papillomavirus (HPV) has morphed from a little-known sexually transmitted infection to a widely known cause of multiple forms of cancer. Each of these transformations in perception was triggered by a new vaccine.
Each new vaccine invited deliberation on how it should be used. That, in turn, focused increased scientific attention on the disease. Often, as federal health officials and other scientists accumulated new information about the disease’s risks and complications, the vaccine maker did its part to market its vaccine. As talk of each disease and its more dramatic aspects spread, public and scientific perception of the disease gradually transformed.
In this country, high vaccination rates rest on a consensus about the diseases prevented by vaccines. When doctors, health officials and, in particular, parents view a disease as serious, they view its vaccine as one worth getting.
The recent increase in the number of philosophical objectors to measles vaccine shows that historical consensus about the disease itself has eroded in recent years. But history also shows that one surefire route to consensus about a disease is fear of that disease. And fear often spreads like wildfire during disease outbreaks, much like what is happening once again now with measles.