Pascal Soriot knows how to make a headline. The AstraZeneca PLC chief executive officer gave a rare interview to the BBC to mark the opening of a £1 billion ($1.3 billion) research facility in Cambridge. But he couldn’t resist a little plug for his vaccine, too.

"If you look at the U.K., there was a big peak of infections but not so many hospitalizations relative to Europe,” he said. His suggestion — made in dulcet tones and bracketed with the caveat that more research needs to be done — is that the AstraZeneca vaccine offers more longer-term effectiveness against serious illness than rival jabs produced by Pfizer Inc. and Moderna Inc. In other words, Britain’s home-grown jab is the reason the country is faring better with the latest COVID-19 wave than Europe.

Only it’s not that simple.