Coronavirus subtype accounts for almost 86 percent of all sequence cases, according to the WHO. BA.2, a sub-variant of the Omicron coronavirus variant, has become dominant worldwide, accounting for almost 86 percent of all sequencing cases, according to the World Health Organization. First detected in early January, the sub-variant is even more contagious than Omicron’s highly contagious siblings, BA.1 and BA.1.1. Here’s what we know about BA.2, often referred to as the “stealth variant”.
Why is it called a “stealth variant”?
This is because BA.2 is slightly more difficult to detect. A gene missing in BA.1 allowed its monitoring by default through a common PCR test. BA.2 and another sibling, BA.3 – also increasing in prevalence but currently low – can only be found by genomic sequence. Although BA.2 is more contagious than other variants of Omicron, studies show that so far it is less likely to cause serious illness.
Are Vaccines Effective Against BA.2?
As with other Omicron variants, vaccines are less effective against BA.2 than other variants such as Alpha or the original coronavirus strain and protection decreases over time. However, according to the United Kingdom Health Insurance Agency, protection is restored with a booster vaccine, especially to prevent hospitalization and death.
Can you catch BA.2 if you already have BA.1?
A major concern about BA.2 was whether it could re-infect people who already had BA.1, especially as some countries seemed to experience “double peaks” in infection rates surprisingly close. However, data from the United Kingdom and Denmark show that while Omicron can re-infect people who have had other variants, such as Delta, only a few BA.2 re-infections in people who have BA.1 have so far been found in the tens of thousands. cases. Scientists say one possible explanation for the recent increase in BA.2 could be that many countries have lifted public health interventions. “In a way, it could just be that BA.2 was the variant that came out when all these people stopped wearing masks,” said Dr. Andrew Pekosz, a virologist at the Johns Hopkins Bloomberg School of Public Health. Eric Topol, director of the Scripps Research Translational Institute, said it was “too early” to see if the US would see a significant BA wave. But whatever the reason for the rise in BA.2, scientists say it is a reminder that the virus continues to cause harm, especially to unvaccinated, inadequately vaccinated and vulnerable populations. “It’s still a huge public health problem and it will continue to be,” said Mark Woolhouse, an epidemiologist at the University of Edinburgh.
