November 12, 2020 - 2:43pm

Earlier this week I wrote about whether we should be excited about the apparent success of the Pfizer-BioNTech vaccine, as seen in preliminary data. (The answer is yes, by the way.) But something I didn’t talk about was whether people would be willing to take it or not.

Ever since 1998 and the benighted, fraudulent Andrew Wakefield paper which purported to link autism to measles virus in the gut — and therefore to the MMR vaccine — we’ve been worried about the problem of anti-vax conspiracy theories and a public afraid of vaccine injury.

For the record, the MMR scare has almost certainly cost lives. While the WHO estimates that while measles vaccinations probably saved 23 million lives between 2000 and 2018, there were still more than 82,000 cases and 72 deaths in 2018 in Europe alone, and the UK All-Party Parliamentary Group (APPG) on vaccines say that “vaccine hesitancy” is on the rise in various places and among various groups.

The question is whether this hesitancy will significantly affect take-up of the various Covid vaccines. I think that, in the UK at least, it probably won’t be the limiting factor. I may be wrong, but here are my reasons.

First, a study from last year found that vaccine uptake in England, which went down after Wakefield, actually rose again and peaked in 2012-13; it has declined somewhat again since then, but by much less, and does not seem to be associated with “anti-vaccination sentiment”.

Second, a paper out today from the London School of Hygiene and Tropical Medicine finds that about 90% of parents either definitely would or lean towards taking a Covid vaccine, and a similar but slightly lower number would give them to their children.

(Another paper from the LSHTM did something really interesting: a randomised controlled trial exposing some people to misinformation and seeing whether it changed their willingness to take a vaccine. It did; I’m somewhat unsure about how seriously to take it, because people’s susceptibility to misinformation given to them by a scientist in laboratory settings might be different to their susceptibility when exposed in the wild. Regardless, it’s reassuring to see RCTs on this stuff.)

Third, the threshold for herd immunity with Covid seems much lower than with measles: you need to get about 95% of the population vaccinated to stop measles spreading, but that figure may be as low as 60% for Covid. So if vaccine hesitancy knocks that 90% figure down to 80%, that’s bad, but not fatal.

Finally, the limiting factor in the short term at least is unlikely to be how many people are willing to take it but how many doses you actually have. There will be enough to vaccinate about 20 million people by the spring. There won’t be enough to go around, so the problem will not be forcing unwilling people to have it, at least until the end of the year.

None of this is to say we should be complacent. Vaccine hesitancy is greatest among some at-risk groups — non-white people and lower-income people. And I am only talking about the UK; the problem will likely be greater in parts of the developing world where there is much greater concern around vaccines. Covid isn’t dealt with anywhere until it’s dealt with everywhere, so that’s not something we can ignore. And idiotic nonsense is definitely being shared by people who should know better.

But I don’t think UK antivaxxers spreading misinformation online will be the difference between success and failure, or even a major contributing factor. For one thing, the mainstream media seems quite capable of spreading the misinformation all by itself, and I really wish they’d stop.


Tom Chivers is a science writer. His second book, How to Read Numbers, is out now.

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