Covid: Omicron sub-variant spreads more than original strain: Study

Omicron sub-variant spreads more than original strain: Study

New Delhi, Feb 1: A study conducted in Denmark has claimed that a sub-variant of Omicron coronavirus strain is even more infectious than the original version.

The research was conducted in 8,541 Danish households and 17,945 household members to examine the transmission of Omicron subvariant BA.2 versus BA.1.

The yet-to-be peer-reviewed finding, posted on the preprint repository MedRxiv, indicates that the rapid spread of BA.2 could be related to the inherent increased transmissibility of the sub-variant, PTI reported.

The researchers said that there is also evidence to support the immune evasive properties of the BA.2 sub-variant. "The study found an overall secondary attack rate of 39 per cent in BA.2 infected households compared to 29 per cent in BA.1 infected households," the researchers from Statens Serum Institut (SSI) said in a statement.

"The risk of being infected was higher in unvaccinated persons compared with vaccinated and booster-vaccinated household members in both BA.2 and BA.1 infected households," they said.
It indicates the positive effect of getting jabbed. When comparing BA.2 relative to BA.1 infected households, there was an increased risk of infection in BA.2 infected households regardless of the vaccination status of the potential secondary case, indicating inherent increased transmissibility of the BA.2 sub-variant, they said.

The unvaccinated BA.2 primary cases transmit the infection to a higher degree than BA.1 primary cases, to both vaccinated and booster-vaccinated household members, the study said. Vaccinated persons infected with BA.2, however, transmit less than vaccinated persons with BA.1, the researchers said.

"We conclude that Omicron BA.2 is inherently substantially more transmissible than BA.1, and that it also possesses immune-evasive properties that further reduce the protective effect of vaccination against infection," the authors of the study added.

In addition to SSI, the team also included scientists from the University of Copenhagen, Statistics Denmark, and Technical University of Denmark. PTI