Many people are now protected from current variants of covid. But that immunity has been acquired at a terrible cost
die—they fade away. And that is what covid-19 is likely to do in 2022. True, there will be local and seasonal flare-ups, especially in chronically undervaccinated countries. Epidemiologists will also need to watch out for new variants that might be capable of outflanking the immunity provided by vaccines.
The polio vaccine took 20 years to go from early trials to its first American licence. By the end of 2021, just two years after-2 was first identified, the world was turning out roughly 1.5bn doses of covid vaccine each month. Airfinity, a life-sciences data firm, predicts that by the end of June 2022 a total of 25bn doses could have been produced. At a summit in September President Joe Biden called for 70% of the world to be fully vaccinated within a year. Supply need not be a constraint.
However, alongside this success is that failure. One further reason why covid will do less harm in the future is that it has already done so much in the past. Very large numbers of people are protected from current variants of covid only because they have already been infected. And many more, particularly in the developing world, will remain unprotected by vaccines or medicines long into 2022.
The combination of infection and vaccination explains why in, say, Britain in the autumn, you could detect antibodies to covid in 93% of adults. People are liable to re-infection, as Britain shows, but with each exposure to the virus the immune system becomes better trained to repel it. Along with new treatments and the fact that more young people are being infected, that explains why the fatality rate in Britain is now only a tenth of what it was at the start of 2021.