US study suggests vaccines up to 89% effective at preventing infection

A new US study says that vaccines may prevent transmission of the coronavirus, which has been a central question about the inoculations.

The Mayo Clinic, in a study of 31,000 people in four US states who received at least one vaccine shot, found the inoculations were around 83% effective at preventing infections 36 days after the first shot.

For people who got both doses, the figure climbed to 89%.

Fifteen days after the first shot, protection against infection was 75%, said the study, which has not been peer-reviewed.

The study covered people who had received the Moderna or Pfizer vaccines.

Vaccines have been found to be highly effective at reducing symptomatic COVID-19 and mortality, but there is a dearth of data on whether they prevent transmission and can stop the virus from circulating within a population.

The question is crucial because most of the population in the US and worldwide remains unvaccinated and other groups, mainly children, are ineligible for the shots.