But these handful of countries have followed two different strategies. The U.S. and most others have tried to make sure that anybody who gets a first vaccine shot gets the second shot within a few weeks (except in the case of the Johnson & Johnson vaccine, which requires only one shot). Britain has instead maximized the number of people who receive one “jab,” as the British call it — and has delayed the second jab, often for about three months.
Kate Bingham, a venture capitalist who led the committee that advised the British government on vaccination, has described the strategy this way: “I think it’s the right public health response, which is to show that you try and vaccinate as many people as possible, as soon as possible. Better to protect everybody a bit rather than to vaccinate fewer people to give them an extra 10 percent protection.”
So far, the data suggest that Britain’s approach is working — because even a single shot provides strong protection against the virus.
A delay seems OK
As Dr. Robert Wachter of the University of California, San Francisco, has written, “According to most vaccine experts, delaying shot #2 by a few months is unlikely to materially diminish the ultimate effectiveness of two shots.”
In Britain, the daily number of new Covid cases has fallen by more than 90 percent since peaking in early January. The decline is larger than in virtually any other country. (In the U.S., new cases have fallen 79 percent since January.) Given that the contagious B.1.1.7 variant was first discovered in Britain and is now the country’s dominant virus form, “Britain’s free-fall in cases is all the more impressive,” Wachter told me. “Clearly their vaccination strategy has been highly effective.”
British deaths have also plummeted in recent weeks:
Britain’s approach not only brings immediate benefits, in terms of lives saved; it also reduces the chances of future outbreaks: The fewer people who have Covid, the fewer who can infect somebody else.
All of this comes with the usual caveat: If the data changes, the lessons should change, too. Based on the current evidence, though, Britain appears to have landed on the most effective vaccination strategy — which is yet another sign of how powerful the vaccines are.