How some vaccines are helping nations to exit Covid faster than others

Messenger RNA shots developed by Moderna or Pfizer and BioNTech are better at stopping people from becoming contagious, shows evidence.

With hundreds of millions of people now vaccinated against Covid-19, the coronavirus outbreak should begin to die down in places where a large chunk of the population has been inoculated. But that isn’t happening everywhere.

Instead, two paths are emerging: In countries such as Israel, new Covid cases are declining as vaccinations spread, while in other places like the Seychelles -- which has fully inoculated more of its population than any other nation -- infections continue to increase or even reach new highs.

One reason for that may be the different types of vaccine being used. Evidence derived from the