CHICOPEE, Mass. (WWLP) – A new COVID variant is making its way through Europe, and has become the dominant variant globally. The BA.2 subvariant of COVID-19, also known as “stealth omicron,” has become the leading variant of the virus.

According to the World Health Organization, the subvariant now accounts for 75% of COVID-19 cases globally. The lead researcher on COVID-19 for the WHO says this is the most transmissible variant of the virus we have yet seen.

BA.2 is not yet the dominant variant of COVID-19 in the U.S. According to the CDC, it accounts for only 23% of COVID cases in our country.

The fact that we saw such a large spike from BA.1 (the original omicron subvariant) just a couple months ago may protect us from another massive surge, health experts say.

One recent model estimated that some 73% of Americans had immunity to the omicron variant, because so many people were exposed between December and February. Still, that would mean about 27% of the population, or nearly 90 million people, are not immune.

Those who have not received a COVID booster shot and people over age 65 are especially vulnerable to this new variant.