The BA.2 subvariant is here — the omicron substrain accounts for nearly 80% of COVID-19 cases at the Stanford hospital, according to Benjamin Pinsky, the medical director of the Clinical Virology Laboratory for Stanford Health Care.
Although Color Genomics does not genotype their Stanford samples, Pinsky said that the student cases on campus likely mirror what the lab is seeing in the surrounding community.
The BA.2 subvariant makes up more than 72% of COVID-19 strains in the United States and is more transmissible than BA.1, the other subvariant of omicron, according to Monica Gandhi, the University of California San Francisco (UCSF) Associate Chief of Infectious Diseases.
BA.2 is more infectious than the previous BA.1 strain, but those infected with omicron early on will have good cross-immunity with BA.2, according to UCSF epidemiology professor George Rutherford M.D. ’75.
While Pinsky estimates that BA.2 is 30% more transmissible than BA.1, Rutherford explained that it does not cause more severe disease symptoms than earlier iterations of omicron.
For those who are vaccinated and boosted, Gandhi says that the BA.2 is not a cause for additional concern compared to previous variants. According to her, the vaccines generate memory B cells that can recognize different variants as they emerge and trigger the production of T cells that amplify the body’s response to a virus and help recruit cells to attack the pathogen directly.
“With hospitalizations at our lowest point since the early days of the pandemic, if you are vaccinated and boosted, there is no reason to take any extra precautions at this time,” Gandhi said. ICU admissions and deaths, as markers of the most severe disease symptoms, also continue to fall.
“This is a normal part of viral evolution, and we’ll continue to see more changes going forward,” Rutherford said.
The best defense against COVID-19, according to Gandhi, is hybrid immunity: vaccination after having been infected previously. Even one dose of the vaccine after infection is encouraged.