In 1981, a virus that had jumped the species barrier some decades earlier to infect humans began to wreak havoc among the gay community in San Francisco and New York. A taskforce was set up to study the cause of this disease, and it took a few years to identify HIV as the definitive cause of Aids and its genome to be sequenced, and nearly 15 years before a cocktail of drugs meant that having an HIV infection was no longer a certain death sentence.
Forty years later, the cause of the Covid-19 outbreak in Wuhan was identified as a new coronavirus Sars-CoV-2, and its sequence determined in a matter of weeks. That, in turn, paved the way for a sensitive test for infection and, now, antibody tests for people who may have had the disease. That we know so much in such record time is due to sustained international investment in science.
However, there is much that we don’t know. We do not know why this virus is so much more transmissible than some others. Whether being infected will make us immune and, if so, for how long. Why it sometimes sets off a severe inflammatory reaction that can lead to death, and why some individuals are more vulnerable to it than others.
Science is also helping to drive the unprecedented worldwide search for a vaccine, but it is the stark reality that, even after 40 years, there is no vaccine for Aids or many other viral diseases. So it is important to put strong efforts into new and repurposed drugs to combat infection.
Such uncertainty is intrinsic to science. Normally, a gradual accumulation of evidence and scrutiny by the community means that mistakes get weeded out and a consensus emerges. That system works well normally, but science is now under the full glare of the public spotlight and under pressure to provide quick answers. In these circumstances, scientists must make clear the uncertainties in their evidence. They must acknowledge that, when faced with such uncertainties, different scientists may reach different conclusions about the likelihood of various possibilities, which will affect their advice. As new evidence emerges, they must be frank about admitting the inevitable mistakes, and be willing to learn from them. They must try to avoid the groupthink that is common to all enterprises and make sure that internal debate is robust. And they must be open about their evidence and conclusions, so that they can be scrutinised. However, it is not possible for scientists to give frank advice if they feel that they will be made the scapegoats for difficult policy decisions.
Moreover, translating science advice into policy can lead to very different paths, as can be seen from the divergent responses to Covid-19 across the world. This is because the science advice is only one factor in policymaking. Governments not only have to contend with the uncertainty of the science but a host of other practical considerations, including feasibility. In all this, they may want certainty from scientists – and feel or claim that they are “following the science” – but wishing something does not make it so.
The most important thing in the middle of a crisis is to constantly review what we are doing against the evidence. If we find we have followed a wrong path, we cannot waste precious time squabbling and apportioning blame. In particular, blaming scientists for their advice in an uncertain situation betrays a fundamental misunderstanding of how science works. It was therefore reassuring to see, last week, No 10 distancing itself from an effort by a minister to blame scientists for their advice.
Instead, when new evidence suggests that we should do something differently or better, both the government and scientists need to acknowledge this, explain why we need to change policy, and change tack accordingly. I think the public will understand that what may, in retrospect, appear to have been poor decisions were made with the best intentions based on what was known at the time – as long as they are recognised and corrected as soon as possible.
Although a viral pandemic was known to be our top threat and the UK thought it was well prepared for one, clearly we were not. We must learn from our successes and failures in this pandemic to be better prepared for the next one that will inevitably strike. That would be a way to honour the tens of thousands of deaths – each one a tragedy.
Venkatraman Ramakrishnan is president of the Royal Society.