Known as BA.2, the new Omicron subvariant is now circulating at low levels in the US. What can you tell your patients? Here's what we know, now.
The COVID-19 Omicron subvariant, known as BA.2, is circulating in the US at "low levels," according to the Centers for Disease Control and Prevention. About half the states have confirmed its presence, with about 127 cases identified as of today.
But in Denmark the subvariant represents more than 80% of cases seen. Case numbers are creeping up in the UK, and BA.2 is becoming the dominant Omicron strain in the Philippines, Nepal, Qatar, and India.
While all data remain preliminary, they point to the potential for an infection that is even more transmissable than the original Omicron strain, BA.1, but not any more infectious. Following is a topline look at what we know now.
Omicron subvariant BA.2: What we're learning. Richard Reithinger, PhD, vice president, global health, RTI International.
CDC: Although BA.2 has increased […] in some countries, it is currently circulating at a low level in the US.
Exposure to Omicron BA.2 carries 39% probability of infection in 7 days vs 29% after exposure to BA.1, according to a study in Denmark.
Omicron subvariant BA.2 is more transmissable than original variant BA.1, and appears to have immune-evasive properties, said Danish researchers.
Subvariant BA.2 was associated with higher household transmission vs BA.1, according to the UKHSA, but vaccines appear to be equally protective.
BA.2 has a “substantial” growth advantage over the original Omicron variant, according to the UKHSA and has spread faster than the original BA.1 variant.
The Omicron BA.2 subvariant also is missing specific spike mutations, making it harder to identify on PCR tests—thus the stealth variant.
“Whether BA.2, or any other Omicron subvariant or other SARS-CoV-2 variant, there is irrefutable evidence that existing vaccines are quite effective in protecting people against infection and highly effective in protecting people from developing severe disease or — worst case scenario — dying upon SARS-CoV-2 infection.” Richard Reithinger, PhD, vice president, global health, RTI International.
“Additionally, even if vaccinated, people should consider adhering to nonpharmaceutical interventions, such as face masks, physical distancing, and handwashing, particularly when in crowded and/or high transmission environments.”