The Battle of Omicron Variants

Deadline reported that Omicron variants BA.2, BA.2.12.1, BA.4 and BA.5 are battling for dominance in America. The share of cases tied to Omicron variants BA.4 and BA.5 increased 79% in the past week. The result is overlapping waves of Omicron in various places around the country.

While BA.2.12.1 gained an advantage by being more transmissible than BA.2 before it, the two newer variants are said to be making inroads at least in part because of their abilities to reinfect.

BA.4 and BA.5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections. Hospitalization  continue to slowly rise all across the country. That means the new variants have a much larger population that they can potentially access via breakthrough infections.

Epidemiologist and biostatistician Dr. Katelyn Jetelina, calls this the “battle of Omicron.”

“After our first massive BA.1 wave,” Dr. Jetelina wrote today in her email newsletter, “BA.2 tried to take hold only to be overtaken by BA.2.12.1. Now, BA.4 and BA.5 are gaining traction very quickly and seem to be easily out competing the rest. Given recent lab studies, though, this isn’t a surprise. BA.4 and BA.5 are particularly good at escaping antibodies and reinfecting people previously infected with Omicron, as well as boosted individuals.”

While BA.2.12.1 spread quickly first the Northeast, it’s now the Midwest — specifically Iowa, Kansas, Nebraska and Missouri — that are feeling the brunt of BA.4 and BA.5. “Once BA.4/5 account for the majority of cases in the U.S., we should expect another (or extended) case surge,” wrote Dr. Jetelina this week.