The European Union wants member countries to require boosters for entry proposing that vaccination be considered valid for 9 months from last shot. Each country sets its own rules but bloc-wide guidance is influential.
Does that mean we’ll need to keep getting vaccinated in order to travel? No, it actually doesn’t mean that.
First of all, though, boosters work. They’re working very well.
Here we focus only on the two mini-waves — first half of Oct, and middle of Nov. Spot the difference…
In Oct rates rose in the elderly just like everyone else. In recent weeks, there is a stark divergence.
But what makes me say that this is boosters and not behaviour? Well… pic.twitter.com/IB9Qhlhqhe
— John Burn-Murdoch (@jburnmurdoch) November 24, 2021
We should think of boosters as third doses. Maybe the first two doses of mRNA vaccines would have worked better spread farther apart (3 weeks between Pfizer doses is insane, this wasn’t an ideal dosing regiment based on science but a design to get through trials quickly in a pandemic and get shots in arms).
Numerous vaccines require three shots. This isn’t unusual. A third shot may suffice for two reasons,
- Our bodies may develop greater immune memory after the third shot
- By the time a fourth shot might be needed, if it indeed is, prevalence of the virus could be low enough that it’s no longer required.
Remember that flu shots are annual but they do not actually last a year. They’re protective for around six months, and of course the effectiveness of flu shots is much lower than that of Covid-19 vaccines developed in the U.S. and Europe. Flu viruses mutate far more quickly than SARS-CoV-2. But antibodies wane quickly so even when the shot is well-matched to circulating viruses it doesn’t last. We don’t get it every six months though, just in advance of flu season.
Fourth doses may be needed in Israel and other places that vaccinated early, and that are taking a conservative approach to the virus and travel. But they probably won’t be required everywhere. And we could see an end to the requirement at some point, probably later than makes sense based on any science, because no political decision-maker wants to be blamed for outbreaks from lifting restrictions on foreigners ‘too early’.