Friday, December 02, 2022

CDC Nowcast: BA.5 Continues To Falter As BQ.1/BQ.1.1 Lead a Diverse Pack of Variants


#17,148


The CDC has published their latest COVID Nowcast, which now as formerly dominant BA.5 in 3rd place with just under 14% of the cases in the country. The tag-team of BQ.1 and BQ.1.1 now make up nearly 62% of the nation's cases while the remainder care due to a mixture of rising and falling subvariants.


While dominant and still rising, BQ.1 and BQ.1.1 aren't climbing as fast as they were a few weeks ago, as several recent entries in the Omicron sweepstakes have emerged, including XBB, BN.1, and BF7.  In the short term, BQ.1/BQ.1.1 should dominate, but it isn't clear how long with will hold court. 

This continual struggle to become king of the viral hill is illustrated by the graphic below, which shows the estimated `share' of week cases that each subvariant has claimed over the past 3 months. 

  
Thus far, we've not seen any evidence that any of these new variants cause more severe illness than earlier Omicron strains, but many are not yet at a level that would send a strong signal. Parsing out COVID hospitalization during a robust flu/RSV epidemic also presents challenges. 

As I reported earlier today (see FDA Withdraws EUA For Last COVID Monoclonal Antibody), we continue to see an erosion in our armamentarium against this virus, and the duration and degree of protection provided by current vaccines against these emerging variants remains to be seen.

As long as this rapid-variant-replacement cycle continues, it is going to be very difficult for vaccines and therapeutic development to catch up.