‘HIV vaccine in the works, but hard to predict timeline’
Research on Acquired Immune Deficiency Syndrome, or AIDS, has advanced tremendously since the disease was first reported in 1981. Anti-retroviral drugs have allowed people living with AIDS enjoy longer and healthier lives. However, the development of an HIV vaccine continues to be a formidable challenge for scientists. MARK FEINBERG, president and CEO of the International AIDS Vaccine Initiative (IAVI), who was in India recently, spoke to Ankur Paliwal about challenges in developing a vaccine, recent breakthroughs, and a rising anti-vaccine movement. Edited excerpts:
Why is it so challenging to make an AIDS vaccine?
Most of the available vaccines against diseases such as polio, measles and yellow fever have one thing in common: they fight diseases against which you have natural immunity. That means your body’s immune system naturally produces antibodies against a pathogen, say polio virus, to destroy it. But what is different about HIV (human immunodeficiency virus) is that most of us do not have natural immunity against it. So, our bodies cannot launch an antibody attack against HIV. There is something about HIV that allows it to escape our immune system. Only a few individuals are able to generate broadly neutralising antibodies, or bnAbs, which can neutralise a large percentage of multiple strains of HIV. Scientists are researching those individuals to study if these bnABs can be developed synthetically. Another challenge is the genetic diversity of the virus. It constantly changes and mutates. HIV attacks the very immune system that is supposed to protect us. Ideally one vaccine should work around the world. But we do not know whether that will be possible.
At what stage is AIDS vaccine research?
A lot is going on. Among other projects, two large studies in Africa are testing two different AIDS vaccines. One is to improve upon the vaccine trial done in Thailand in 2009, which for the first time showed that the vaccine provided 30 per cent protection against HIV. Another study is testing a global HIV vaccine to check whether or not it is effective against most HIV strains. Africa has all the strains of the virus, including Clade C, which is prevalent in India. But it is hard to say when the vaccine will be available. However, significant progress has been made on other interventions, which are likely to be available in the next five years. These include regimen advancement of pre-exposure prophylaxis, or PrEP drugs, from one pill a day to a pill once a week or once a month. PrEP is generally prescribed to people who are at high risk of getting infected. Similarly, researchers are testing whether broadly neutralising antibodies can be used as a PrEP injectable once every three months or so. We are going to keep improving the interventions as we work towards developing a vaccine.
What role is robotics playing in vaccine research?
Robotics is transforming the vaccine development process. Scientists have used robotics to shorten the time required to produce stable cell lines, which are needed to produce antibodies for a vaccine.
In a recent interview, you said the world was going to be in a much riskier place if the public-private partnerships continued to fail in developing vaccines...
We do not have effective tools against a lot of infectious diseases, including ebola, zika and AIDS. Traditional vaccine manufacturers are used to developing vaccines against infections that many people would get. For diseases like ebola and zika, you do not know what the outbreak trajectory will look like. But we cannot wait for outbreaks to occur. So, we have to develop vaccines for pathogens we know about, and make vaccines faster for pathogens we do not know about. The government has a public health responsibility but that does not mean that it needs to do all the work by itself. Different elements come from different places. So, the best scientific ideas tend to come from academic groups, development of vaccines is the expertise of industry, and the government knows what public health needs are, and can fund the project. If the governments were to take that on all of it, they would not have the expertise or capabilities to deliver the results, especially when it comes to infections that are unpredictable.
Recently, people protested in the US, Italy and other countries against making vaccines mandatory in national programmes. Do you think scientists are a part of the problem because they do not engage with the public to address their fears?
The anti-vaccine movement falls into the category of well-meaning people who do not have access to accurate information. That well-tested vaccines are safe is proven. Scientists might not know what is the best way to reach out to the public and deal with the skepticism around vaccines. Sometimes, the problem is that when scientists engage with people, they speak a different language. With the increase in inaccurate and unscientific information floating around, the job of scientists is getting harder. So yes, they need to engage better.
Should people be given a choice to deny taking the vaccine?
People do not have a choice to put fellow citizens at a risk that could kill them.