Issue #61: Vaccines, HIV, harm reduction and COVID-19

Written by Nobel Laureate Professor Peter Doherty

Writing about vaccines for the past four months (#43 to #60), my focus has been on the ‘hard sciences’ of molecular biology, virology, epidemiology, numbers, statistical analysis and so forth that allow us both to make these products and to evaluate them in various contexts. But when it comes to public health strategies (including vaccination), there are also very different, yet equally important, areas of professional expertise based in communications and the behavioural sciences.

As a laboratory-based scientist who trained initially in veterinary (not human) medicine, I first became conscious of the enormous importance of the social sciences during the earlier phase of the HIV/AIDS pandemic that marked the last two decades of the 20th century. The HIV pandemic is, in fact, continuing, though it is suppressed in those countries with the resources to supply the very specific drugs (small molecules) that hold the virus in check and allow people who are infected to live relatively normal lives. If only we had a vaccine against HIV but, despite enormous effort and expenditure, that just hasn’t happened. I’ll discuss the HIV vaccine challenge next week.

Before we had drugs, though, what did work with HIV/AIDS was enlightened political leadership that listened to the relevant medical professionals and embraced the open dissemination of good information. That led to the elimination of any ‘blame game’ or punitive component from the public heath response and provided readily accessed health care clinics for those at risk. Australia’s evidence-based, bipartisan approach during the Hawke administration proved extremely effective, while the US under Ronald Reagan kowtowed to ‘conservatives’ and was a disaster. We saw repeat performances from Prime Minister Scott Morrison and President Trump with COVID-19, though the situation in the US has now changed dramatically under the leadership of Joe Biden.

Apart from embracing evidence rather than prejudice, what worked in (particularly) the poorer nations was the implementation of communications strategies that had politicians, the military and other people of influence – especially the leaders of the various religious communities – singing from the same hymn sheet. This was my introduction to the whole field of evidence-based ‘harm reduction’. Teams led by social scientists from Melbourne’s Burnet Institute, for example, provided some of the most effective programs in this area as, contracted by various national governments, they helped develop locally effective approaches that encouraged the necessary changes in human behaviour.

Once it was clear that the blood supply (including blood products) was clean, people could choose to embrace behaviours that did not put them at risk of HIV infection. But it can be immensely difficult to change sexual practices and vulnerable people can be abused, especially when alcohol is involved. With COVID-19, we can’t decide not to breathe, but we can comply with mandates to social distance, restrict our movement and wear face masks when required to do so. Even so, we’ve seen how that plays out when we have prominent communicators who, for various reasons, spread disinformation or are simply unable to grasp the basic concepts of infection and immunity. We’ve experienced relatively little of that in Australia and the claim that mandating face masks in at-risk situations is an abuse of basic freedoms, a message that has resonated with elements of the US community, does not readily translate to the Australian way of thinking.

When it comes to COVID-19, the harm reduction strategy that is vitally important for this country to open up to the rest of the world is to achieve a sufficiently high level of vaccine coverage. Unlike the situation for HIV, we have great vaccines that (even with the emergence of mutant SARS-CoV-2 strains) are protecting against the development of severe disease and death. Still, no matter how effective a vaccine may be in preventing symptoms, overall efficacy is clearly dependent on achieving a sufficiently high level of community coverage. With COVID-19, we should see clear evidence of ‘herd immunity’ once 70-80% of the population is vaccinated.

Among relatively informed people, the clotting issue with the AstraZeneca vaccine plus the lack of availability of the PfizerBioNTech alternative has clearly impacted negatively on vaccine uptake. In Victoria at least, that negative trend has been substantially reversed since the virus outbreaks related to the Kappa, then Delta SARS-CoV-2 variants have led to a further lockdown. With virus active in the community, people who are generally aware think in terms of relative risk and come to the obvious conclusion that the equation is clearly weighted in the direction of being vaccinated as soon as possible with whatever is available.

Very much in the harm reduction ballpark, there can be specific issues when it comes to reversing COVID-19 vaccine hesitancy for relatively recent immigrants, particularly those who fled violence and repression and regard authority figures with suspicion. Part of the solution here is to involve prominent individuals from within those communities, both as ‘influencers’ and providers of general support. And it is massively important that public health communications teams include people who have appropriate cultural backgrounds and language skills, both to answer questions and to understand where particular concerns are coming from. As with any communication all interactions should, so far as that’s possible, be based in understanding, trust and mutual respect. In general, that’s also a good message for civil society.