Tuesday, July 05, 2022

CDC Nowcast: BA.5 Now > 50% of U.S. COVID Cases



As we've been expecting, Omicron BA.5 has quickly become the dominant COVID variant across the nation, ending BA.2.12.1's dominance after only 7 weeks on top.  BA.4, while gaining a little more ground, still lags behind BA.2.12.1. 

BA.1.1 - which was dominant in the spring - is virtually extinct, while its successor BA.2 barely registers (2.8%). 

While Alpha and Delta each reigned for six months (or longer), since late November new Omicron variants have emerged, and risen to dominance, every 8 to 10 weeks.   Even as BA.5 has become dominant in the United States, we are already looking downrange at what might be the next rising star.

Everything we're seeing suggests that BA.5 (and BA.4) are more likely to evade prior immunity than earlier variants, meaning that even those who have (even recently) recovered from the virus - or have received their booster vaccination - may be at risk of infection.  

Vaccination (and boosters) - along with prior infection - are still expected to reduce the severity of COVID illness, however. 

We have seen hospitalizations increase in some countries where BA.5 has taken off, but it remains  unclear whether that is due more to the sheer volume of infections rather than to an increase in disease severity. 

Given the potential for `Long COVID', and recent studies warning of the possible risks of reinfection (see Outcomes of SARS-CoV-2 Reinfection), it still makes sense to avoid this infection whenever possible. 

The latest update from the CDC's NOWCAST: 

Surveillance, testing, and genomic sequencing are limited (and variable) around the country, so all of the above numbers should be viewed as rough estimates, We may see further revisions to the data in the weeks ahead.

Given the enhanced transmissibility of BA.5, and our recent 4th of July Holiday, we are likely to see a significant bump in cases in the next few weeks. 

Which is why - even though I am fully vaccinated, and got my 2nd booster last month - I'm continuing to wear a face mask in public, carry (and use) hand sanitizer, and avoid crowds when possible.

Whether that will be enough to avoid reinfection with BA.5 - or whatever comes after - remains to be seen. 

We live in interesting times