CDC Nowcast - May 24th
#16,782
Although it has taken nearly 3 months, the BA.2.12.1 Omicron variant has finally overtaken, and eclipsed the BA.2 variant here in the United States. All regions, except the Pacific Northwest (region 10) are reporting >50% of cases now BA.2.12.1.
Somewhat unexpectedly, B.1.1.529 - which was dominant in December and January, but had dropped to less than 1% of cases two weeks ago - has staged a minor rebound. The CDC estimates it to comprise 2.8% of cases this week.
Given the limits of surveillance, testing, and genomic sequencing around the country, all of these numbers should be viewed as rough estimates, and we may see further revisions to the data in the weeks ahead.
Excerpts from this week's nowcast follow:
It is no coincidence that the areas reporting the highest incidence of BA.2.12.1 are reporting surges in infections and increased hospitalizations, although cases still appear to be milder than with Delta.
The $64 question is what comes next.
Since Omicron (B1.1.529) emerged last November and began its world tour, we've seen a procession of newer, more transmissible variants (BA1, BA1.1, BA.2, BA.2.12.1) emerge and rise to dominance every 6 to 8 weeks.
Many are looking at BA.4 and BA.5 - currently circulating in South Africa and recently detected in the UK - as the next likely heir apparent.
As long as SARS-CoV-2 continues to generate newer, more transmissible, variants this vicious cycle will undoubtedly continue.
