Coronavirus variant update: and on to the BA.4/5 wave

Moderna says updated COVID shot boosts Omicron protection

Boston Globe – June 8

(AP) Moderna’s experimental COVID-19 vaccine that combines its original shot with protection against the omicron variant appears to work, the company announced Wednesday.

COVID-19 vaccine makers are studying updated boosters that might be offered in the fall to better protect people against future coronavirus surges.

Moderna’s preliminary study results show people given the combination shot experienced an eight-fold increase in virus-fighting antibodies capable of targeting the omicron mutant, the company announced.

Today’s COVID-19 vaccines all are based on the original version of the coronavirus. They’re still providing strong protection against severe disease, hospitalization and death even after the appearance of the super-contagious omicron variant — especially if people have had a booster dose. 

But the virus continues to mutate rapidly in ways that let it evade some of the vaccines’ protections and cause milder infections.

So U.S. regulators, and the World Health Organization, are considering whether to order a change in the vaccine recipe for a new round of booster shots in the fall — when cold weather and kids returning to school are expected to drive yet another surge. …

Two new versions of Omicron are gaining ground in the US, according to CDC estimates

NY Times – June 8

The Omicron subvariants known as BA.4 and BA.5 now represent 13 percent of new coronavirus cases in the United States, up from 7.5 percent a week ago and 1 percent in early May, according to new estimates from the Centers for Disease Control and Prevention.

The spread of the subvariants adds more uncertainty to the trajectory of the pandemic in the United States, where current case counts are likely to be a significant underestimate. But whether it leads to a major new wave of infections, or spikes in hospitalizations and deaths, remains unclear, scientists cautioned.

The new figures, which were released on Tuesday, are based on modeling, and the C.D.C.’s estimates have missed the mark before. But the overall trend suggests that BA.4 and BA.5 could outcompete the two other Omicron subvariants, BA.2 and BA.2.12.1, which together account for most U.S. cases, said Denis Nash, an epidemiologist at the CUNY Graduate School of Public Health & Health Policy.

“This could happen very quickly,” Dr. Nash said.

Data on BA.4 and BA.5, which were first detected in South Africa in early 2022, remain limited. But these variants seem to spread more quickly than earlier versions of Omicron, such as BA.2, and may be better at dodging the immune system’s defenses. So far, there is not much evidence that they cause more severe disease, although more studies are needed. …