CDC Director Dr. Rochelle Walensky said Wednesday that experts have not yet seen studies suggesting omicron sub-variant BA.2 will evade COVID-19 vaccine protection any more so than the original omicron strain has already.
“In terms of early studies, we have not seen any studies that suggest it’s more severe, nor have we seen studies that suggests that it will evade our vaccines any more so than omicron has already – and, in fact, that our vaccines will work just like it has with omicron,” Walensky said at the White House COVID-19 response team briefing.
Omicron now makes up 99.9% of new COVID-19 cases.
According to Walensky, genomic surveillance is detecting BA.2 projecting at “around 1.5%” in the U.S.”
“Of course, that varies for different parts of the country, but around one of – 1.5% projection of the sequences that we’re seeing,” she explained.
What is known, she highlighted, is that BA.2 does have a “modest transmission advantage” over BA.1 – though “not nearly the transmission advantage” between the omicron and delta variants.
“In terms of how we anticipate this will impact cases: In many places we’ve seen BA.2 so far, cases have continued to come down, although at a slower rate,” Walensky added.
“In some countries, like Denmark, cases have gone up associated with BA.2, but that’s also in the context of relaxing mitigation strategies, mitigation measures, which is why we’re currently keeping those in place, among the reasons,” she said.
The “stealth” version of omicron has genetic traits that make it trickier to detect, though much remains unknown and it is not yet a variant of concern.
The World Health Organization (WHO) says investigations of BA.2, which has been found in at least 40 countries, “should be prioritized.”
“As of 24.01.2022, the BA.2 descendent lineage, which differs from BA.1 in some of the mutations, including in the spike protein, is increasing in many countries. Investigations into the characteristics of BA.2, including immune escape properties and virulence, should be prioritized independently (and comparatively) to BA.1,” the agency said on its website.
Since November, more than three dozen countries have uploaded nearly 15,000 genetic sequences of BA.2 to GISAID, a global platform for sharing coronavirus data.
With BA.2, medical professionals advise taking the same precautions as with omicron: getting vaccinated and boosted, social distancing and staying home when sick and following public health guidance regarding wearing masks.
The Associated Press contributed to this report.