Largely fueled by the highly transmissible Omicron subvariant BA.5, a new and potentially deadly coronavirus wave appears to be starting in New York City, NBC New York has reported.

Dr. Jay Varma, an infectious disease physician and senior advisor for public health under former Mayor Bill de Blasio, said that recent data indicate that Covid-19 infections in the city have stabilized at a high level rather than trending lower. “The decline of reported #COVID19 cases in NYC has stopped. Reported cases are at a high plateau, which means actual transmission is very high when you account for the >20x under-counting. This is likely the beginning of a BA.5 wave,” Varma tweeted, per the news outlet. “Experience from other countries means there will be another big increase in NYC #COVID19 infections, including among those who have had #Omicron in past few months,” he continued.

ABC News reported that as of June 26, New York City’s test positivity rate hit 10.05 percent, according to the Department of Health and Mental Hygiene. It marked the first time that the rate has eclipsed the 10 percent level since January 22. However, the true test positivity rate could even be higher due to the fact that a number of people testing positive for the virus via at-home rapid tests are not reporting their results to health officials.

Across the United States, BA.5 makes up nearly 37 percent of all Covid-19 cases, according to the Centers for Disease Control and Prevention (CDC), which is more than double the prevalence from the previous two weeks. Combined with another highly contagious subvariant, BA.4, they now account for more than half of all cases.

“BA.4 and BA.5 have come out of nowhere the last two weeks.” Dr. Roy Gulick, chief of the division of infectious diseases at New York-Presbyterian and Weill Cornell Medicine, told ABC News. “They are more transmissible than the other recent variants we've seen, they're less susceptible to antibodies both from previous infection or from vaccination—but they don't seem to cause more severe disease,” he added.

In response, the Washington Post reported that the U.S. Food and Drug Administration (FDA) announced on Thursday that the next round of coronavirus booster shots, likely rolling out this fall, will be modified to target the Omicron sub-variants BA.4 and BA.5 in addition to the original strain of the virus.

“As we move into the fall and winter, it is critical that we have safe and effective vaccine boosters that can provide protection against circulating and emerging variants to prevent the most severe consequences of COVID-19,” Dr. Peter Marks, director of the Center for Biologics Evaluation and Research at the FDA, said in a statement.

Ethen Kim Lieser is a Washington state-based Finance and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.

Image: Reuters.