Britain and EU May Both Be Wrong on Astra's Vaccine
The U.K. and Europe are recommending different age cutoffs for inoculations using Astra’s shot to limit blood-clot risks. Neither of them is right.
Younger people may be more at risk of blood clots from Astra’s shot. Setting appropriate age restrictions requires weighing risks and benefits.
Photogrpaher: Russell Cheyne - WPA Pool/Getty Images
When it comes to Covid-19 vaccinations, Britain has been a bit of a renegade. At the outset of the global rollout, the U.K. — in an effort to inoculate as many people as possible as quickly as possible — started its campaign by lengthening the time interval between the first and second shots beyond what was indicated from trials.
Instead of a recommended gap of as little as three weeks for the Pfizer Inc.-BioNTech shot or six to 12 for the one developed by AstraZeneca Plc and the University of Oxford, the government stretched the interval to 12 weeks for all cases. It was a risky gamble that invited criticism from health experts and analysts (myself included) who worried the untested move might lead to subpar protection and enable the generation of virus variants.