https://news.yahoo.com/covid-reinfections-set-to-spike-in-us-as-new-variants-evade-immunity-220029351.html

Two mutants matching that description, BA.4 and BA.5, are now taking off in the U.S. — and experts say they will soon outcompete the earlier versions of Omicron (BA.2 and BA.2.12.1) that have already been causing hundreds of thousands of new (and mostly unreported) infections every day for weeks on end.

BA.4 and BA.5 then evolved to dodge the enormous amount of immunity induced by the original Omicron — and over the last month, their share of U.S. cases has been roughly doubling every seven days, signaling exponential growth. At the same time, U.S. reinfection rates appear to be rising. By July, BA.4 and BA.5 will likely be dominant nationwide.

Portugal, for instance, is currently experiencing a big BA.5 wave, and COVID deaths are again approaching winter’s Omicron highs, even though 87% of the Portuguese population has been fully vaccinated — 20 points higher than in the U.S. In contrast, the official COVID death count in South Africa remained fairly flat during that country’s recent BA.4 spike (though excess deaths were up sharply). In South Africa, just 5% of the population is over 65; in Portugal, that number is 23%. The U.S. — where seniors represent 16% of the population — is much more like Portugal demographically. Even small setbacks in protection for the immunocompromised and the elderly can have a real impact.