Covid vaccine rush could make pandemic worse, say scientists

The rush to immunise populations against Covid-19 could lead to the rollout of a vaccine that is not very effective and risk worsening the pandemic, leading scientists have said. Politicians and commercial companies are competing to be the first to license a vaccine, but experts say the world would be better served by waiting until comprehensive results showed at least 30-50% effectiveness.

Ministers announced on Friday that the UK would take emergency powers to push any vaccine through the regulatory processes with unprecedented speed before the end of the year. Donald Trump wants to be able to announce the US has a vaccine before tthe presidential election on 3 November.A vaccine is vital to stopping the pandemic, but Prof Sir Richard Peto of Oxford University and an adviser to the World Health Organization, said the first vaccine would be bought and used all over the world even if it had low efficacy.

Even if it protected only a minority of the population, it would be regarded as the standard by which later vaccines would be measured. That could even lead to inferior vaccines being approved, because they would not have to show that they were any better. There is huge political and commercial momentum in the UK behind the Oxford/AstraZeneca vaccine, which is ahead of most other contenders in the world. Trials are taking place in a number of countries, including those with high levels of infection, such as South Africa and Brazil, where how well it works will become clear more quickly .

Peto is a member of the WHO’s Solidarity Vaccines Trial Expert Group, which is made up of leading scientists around the world who are advising on the establishment of the WHO’s trial to compare different vaccine candidates. The group said in the Lancet medical journal last week that a poor vaccine would be worse than no vaccine, not least because people who had it would assume they were no longer at risk and stop social distancing. Good results on safety and effectiveness do not guarantee there will be no long-term problems, they add. The vaccine’s protection may wane, for instance.

Source: The Guardian