From squandering global vaccine supplies to the possibility of undermining immunity from the first two doses, booster programmers are a surprisingly complicated business.
The turning point came just after 6:30 on a Tuesday morning.
It was the 9 December 2020 and 91-year-old Margaret Keenan and 81-year-old William Shakespeare – who delighted the world by hailing from Warwickshire, like the poet – had just become the first people to ever receive an initial dose of a Covid-19 vaccine outside clinical trials.
The entire room burst into applause. The day was named “V-day”, and the atmosphere was giddy. One British newspaper celebrated with the whimsical headline “The taming of the flu” – while footage of a particularly charismatic early vaccine recipient, who was more concerned about his “rather nasty lunch” than the needle went viral on Twitter. The pandemic was far from over, but this was the first step on the way out.
Nine months later, around 5.7 billion doses of various vaccines have now been administered worldwide – with 41.8% of the global population at least partially protected. But the list of unknowns is growing by the day.
“One ghastly thing about this pandemic is that people get cross with us [scientists],” says Danny Altmann, professor of immunology at University College London, “because we change our minds, because it’s such a moving target.”
Now that it’s clear the world is likely to be riddled with Covid-19 – and its many variant successors – for years to come, the next big question is whether two doses of each vaccine is enough.
Altmann explains that not that long ago – in April and May – he was writing articles and giving interviews saying that most vaccinated people had immunity that was so stupendous, there was no need to worry about booster doses.
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