Health officials tracking two new COVID omicron subvariants; eyeing BA.4 and BA.5

STATEN ISLAND, N.Y. — The World Health Organization (WHO) announced on Monday that it is tracking two new subvariants of the virulent omicron strain of the coronavirus.

A few dozen cases of the strains, known as BA.4 and BA.5, are being eyed by the WHO. Meanwhile, the omicron BA.2 variant has been predominant in the United States since last month.

The agency reportedly said it is tracking the new variants for their “additional mutations that need to be further studied to understand their impact on immune escape potential.”

Omicron was found late last year to have increased ability to transmit between people and also reduce the effectiveness of current vaccines. Hospitalizations in the borough rose to levels not seen since the first wave of the virus in the spring of 2020.

Federal data indicates the BA.2 omicron subvariant accounts for nearly three-fourths of all sequenced cases, continuing a steady rise in prevalence that began in January. Dr. Ashwin Vasan, the city’s health commissioner, previously said the citywide rise in new cases is due to the virulent strain of the virus.

New York City Health Department data shows the five boroughs have experienced a slight but consistent case rise in recent days after a precipitous fall from record-setting case numbers observed this past winter. The Northeast of the United States as a whole, however, has seen a stark rise in new case totals.