A growing COVID strain — Omicron subvariant XBB.1.5 — may be more likely to infect the vaccinated and those who’ve already had the virus, New York City health officials tweeted Friday.

“Omicron subvariant XBB.1.5 now accounts for 73% of all sequenced COVID-19 cases in NYC,” the city’s Department of Health and Mental Hygiene said. “XBB.1.5 is the most transmissible form of COVID-19 that we know of to date and may be more likely to infect people who have been vaccinated or already had COVID-19.”