By now you may have heard there’s a newer version of the Omicron variant of Covid-19 that is making its presence felt. The original Omicron variant is known as BA.1 and the new version is called BA.2. Just when you thought we were nearly past the Omicron wave, now comes this new version of itself.
The BA.2 variant of Omicron is under observation by Denmark, India, and the U.K., reports Renee Onque and Denise Roland in The Wall Street Journal. This second variant arose around the same time as the first and comes from the same ancestor strain. According to Theodora Hatziioannou, associate professor of virology at Rockefeller University, the differences between this variant and the BA.1 can be seen in the spike protein of the virus.
This is the first time that two competing variants have emerged in parallel like this, according to Mark Zeller, a genomic epidemiologist at the Scripps Research Institute in San Diego, California. He expected this second variant will drive a rise in cases, but not as much as the original because people who were infected with the original likely have some immunity to BA.2.
The BA.2 variant has been detected in the U.S., according to the CDC. The CDC estimates show that Omicron was likely responsible for 99.9% of Covid-19 infections in the week ending January 22nd. The prevalence of other variants including BA.2 was included in that study. No further data is available yet.
The BA.2 variant has been detected in at least 40 countries including the U.K., Denmark, India, Sweden, Singapore and the Philippines. BA.2 appears to be displacing the BA.1 variant in Denmark. As yet, the World Health Organization has not designated the BA.2 as a “variant of concern.” It isn’t clear yet whether the BA.2 variant behaves any differently than the original Omicron strain. One study at the Serum Institute of Denmark suggested BA.2 may well be over one and a half times more contagious than BA.1. The CDC disputes this conclusion saying, “Currently there is no evidence that the BA.2 lineage is more severe than the BA.1 lineage.”
Those monoclonal antibody treatments originally developed by Regeneron for the Alpha and Delta variants have been less effective with Omicron. However, the monoclonal antibody treatment known as sotrovimab, made by GlaxoSmithKline PLC and Vir Biotechnology, has shown effectiveness against the BA.1 variant and likely will also be effective against BA.2. “We are confident that sotrovimab will continue to provide significant benefit for the early treatment of patients hoping to avoid the most severe consequences of Covid-19,” said George Scangos, chief executive of Vir.
Pfizer and Merck and its partner Ridgeback Biotherapeutics developed antiviral pills for Covid-19 that continue to work against the original Omicron variant and may have similar effects against BA.2. Vaccines are also expected to be just as effective against BA.2 as they are against BA.1.
“I can be pretty confident in saying that vaccines will continue to work really well at keeping people away from the hospital if they are boosted,” said Peter Chin-Hong, infectious disease specialist at the University of California, San Francisco. “When fully vaccinated and boosted, your cells adopt memory and are able to detect similar variants, preventing you from getting extremely sick if infected,” said Dr. Chin-Hong.
