Omicron sub variant BA.2 more contagious, evades vaccine protection: Study

The BA.2 Omicron subvariant is inherently more contagious than the original BA.1 strain among both vaccinated and unvaccinated people, according to a Danish study.

The yet to be peer-reviewed study revealed fully vaccinated people are more likely to catch BA.2 than the previous strain, but they are less likely to spread it to others, CNBC reported.

That also indicates the subvariant is even better at escaping vaccine protection than BA.1, which was already significantly more contagious than any other Covid variant, said researchers affiliated with the University of Copenhagen and the Danish Health Ministry.

On the other hand, 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.

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The researchers also found that people who received a booster were even less likely to transmit the virus than people who were fully vaccinated, the report said.

"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 study also noted that 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 daycare.

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According to the World Health Organisation, the probability for spreading within a household was 39 per cent for BA.2 versus 29 per cent for BA.1, the original Omicron strain.

The global health body hasn't yet labelled BA.2 a separate variant of concern from omicron. However, WHO officials have warned that new variants will almost certainly emerge as Omicron spreads at an unprecedented rate around the world.

"Currently there is no evidence that the BA.2 lineage is more severe than the BA.1 lineage," CDC spokesperson Kristen Nordlund was quoted as saying.

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