The data is encouraging as it shows that the bivalent booster injections, which were updated to match the BA.4 and BA.5 versions of the omicron variant and began rolling out in September, provide protection against new coronavirus variants before a possible winter wave of cases.
Moderna also said preliminary analysis with a small number of subjects showed that the antibodies generated by the bivalent booster lost some potency against the difficult and fast-growing BQ.1.1 subvariant — but could still block it. BQ.1.1 accounts for about a quarter of cases in the United States, according to the Centers for Disease Control and Prevention.
“Evolution is a dangerous thing to bet against. The virus continues to surprise us and we must be ready to update the vaccine,” said Stephen Hoge, president of Moderna. But he added that he was encouraged by the high levels of antibodies induced by the booster shot as the country heads into winter.
“I think we’re optimistic that this bivalent containing BA.4/BA.5 will be enough to get us through,” Hoge said.
Moderna’s announcement will intrigue scientists are considering future booster strategies because the makers of the two messenger RNA coronavirus vaccines have now presented converging results showing that their bivalent injections elicit a stronger response than their original formulations.
But the news is kind of an artificial comparison with the general public because those original boosters are no longer available. The decision to switch was made over the summer to ensure sufficient supplies to immunize people with the updated vaccines before a possible spike in cases in the winter.
It is also it’s unclear whether the data will help spark public interest in the boosters. Only about 10% of people ages 5 and older in the United States received a bivalent booster, according to CDC data.
To measure the effect of the additional vaccine, the scientists compared the antibodies blocking the virus in the blood of 511 people, before and after the bivalent booster or the original one. What these types of lab experiments cannot predict is how well or for how long higher antibody levels will protect people from infection or serious illness. Most scientists expect boosters to help build protection against worse outcomes, but won’t provide as strong protection against infection.
Moderna reported that its bivalent booster created five to six times the level of antibodies compared to the old booster. This is a bigger advantage than the effects of a previous bivalent booster set to fight the BA.1 variant. But some scientists have questioned whether the differences between the two groups of people who received each type of shot might be partly responsible for some of the benefits.
In contrast, Novavax, a latecomer in the vaccine race, presented data last week suggesting that a bivalent booster of its vaccine including the omicron BA.1 subvariant did not offer an advantage over its booster. of origin.
The company did not present data on a bivalent vaccine containing BA.4/BA.5, but argued that its original vaccine may continue to provide protection, instead of updating the formula. It is not known why there are divergent results. Novavax chief medical officer Filip Dubovsky said last week that the company’s vaccine could induce a broader response to variants, which is then enhanced by repeated increases in the older formulation. Unlike the widely used messenger RNA vaccines from Pfizer-BioNTech and Moderna, the Novavax vaccine is a protein-based vaccine with an added substance called an adjuvant that is designed to activate the immune system.
Novavax said it may update its plan if required by regulatory agencies.
“We’re kind of ready to respond to whatever is needed,” Dubovsky said. “But we actually think we have a case that sticks with what we have now, and seems to be working now, is the way forward.”
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