In its weekly update on COVID-19, the World Health Organization (WHO) said the same day that the number of cases has dropped 76 percent in the past 28 days compared to the previous 28 days, the CIDRAP website reported on March 2. At the same time, WHO warned that the numbers are underestimated due to reduced testing and delayed reporting.

All regions of the world have seen a decrease in the number of cases; deaths have fallen in all regions except the eastern Mediterranean.

In its variant update, the WHO said that Omicron recombinant strains, mainly XBB.1.5, are making up an increasing share, rising to 41.5% from 18.7% in the first half of January. XBF, which was added as a variant in surveillance a few weeks ago, accounted for an estimated 1.2% of sequenced samples.

In a separate report, the latest assessment of XBB.1.5 by the WHO Technical Advisory Panel on the Evolution of SARS-CoV-2 Virus said the subvariant may be contributing to an increase in cases given the strong evidence of transmissibility and moderately strong evidence of immune evasion. So far, XBB.1.5 does not appear to pose an additional public health risk over other Omicron variants currently prevalent, the team said.

In other COVID developments, Pfizer and BioNTech announced the same day that they have submitted an Emergency Use Authorization (EUA) application for use of their bivalent COVID vaccine as a booster (fourth dose) for children under 5 years of age who have already had a primary series of vaccinations.