Omicron subvariant better at escaping vaccine protection than original - study

In most countries, the Omicron BA.1 variant is prevalent, but in Denmark the more contagious BA.2 subvariant has clearly become dominant in Denmark. It is no coincidence, then, that Danish researchers have investigated this subvariant perhaps the most thoroughly. Their key findings, according to a CNBC summary, are as follows:

• the Omicron BA.2 subvariant is inherently more contagious and better at evading vaccines than any other Covid strain;
• it spreads more easily across all groups regardless of sex, age, household size and vaccination status;
• at the same time, vaccinated people do not transmit it as easily as the unvaccinated;
• transmission rates among unvaccinated people were higher with BA.2 compared to BA.1, indicating unvaccinated people were carrying a higher viral load with BA.2;
• although fully vaccinated people are more likely to catch BA.2 than the previous strain, they are less likely to spread it to others
• the probability for spreading within a household was 39% for BA.2 versus 29% for BA.1;

• people who received a booster were even less likely to transmit the virus than people who were fully vaccinated. “This indicates that after a breakthrough infection, vaccination protects against further transmission, and more so for BA.2 than BA.1," the scientists found;

• the higher susceptibility to infection and greater transmissibility of BA.2 will likely result in more extensive spread of the virus among unvaccinated kids in schools and day care;
• Covid BA.2 infections are generally milder than delta variant infections, and vaccines help protect against severe illness and hospitalizations.

The study, led by a team of scientists affiliated with the University of Copenhagen and the Danish Health Ministry among other institutions, has not yet been submitted for peer review.  

Cover photo: Getty Images