While the number of cases of the Omicron variant has been decreasing over the past few weeks, health officials are concerned about the BA.2 variant, which appears to be more transmissible than the Omicron variant.
The BA.2 variant is responsible for roughly 20% of the cases worldwide, with the number of cases doubling every week.
Early studies from the United Kingdom and Denmark show the BA.2 subvariant is about 30% more transmissible than the original BA.1 Omicron variant. Despite being more contagious, the mutated strain does not appear to be causing a sharp increase in the number of hospitalizations or severe cases of COVID-19.
"As of now, I don't think that we need to sound a global alarm. But I do think that we need to pay attention to BA.2 because it does appear to have a growth advantage over BA.1," Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, said.
Health experts say that while the strain can evade protection from vaccines and natural immunity, many recently vaccinated or boosted people still have a high level of neutralizing antibodies that can fight off the infection.
"The situation that we're seeing on the ground, and I get this from talking to a number of my colleagues who actually do the genomic surveillance, is BA.2 is kind of creeping up in terms of numbers, but it's not the meteoric rise that we saw with BA.1," Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan in Canada, said, according to CNN.
"It's so soon after that initial BA.1 peak that you have a lot of people who were either vaccinated or boosted ... [or] got Omicron, and so right now all of those people will have relatively high titers of antibodies, neutralizing antibodies that will protect against infection," Rasmussen added.