The data are encouraging because they show that the bivalent booster shots, which were updated to match the BA.4 and BA.5 versions of the omicron variant and first launched in September, provide protection against the newer coronavirus variants earlier. case surge season.
Moderna also said that preliminary analysis with a small number of subjects showed that the antibodies produced by the bivalent booster lost some potency against the challenging 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. This 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 level of antibodies caused by the booster shot when the country was winter.
“I think we are optimistic that this BA.4 / BA.5-containing bivalent will be enough to get us through,” said Hoge.
Moderna’s announcement will be intriguing scientists thinking about future booster strategies because the manufacturers of both messenger RNA coronavirus vaccines have now presented convergent results showing their bivalent shots trigger a stronger response than their original formulation.
But the news is an artificial comparison for the general public because the original boosters are not available. The decision to move was made in the summer to ensure a sufficient supply to vaccinate people with the updated shots before the possible spread of winter cases.
That too It is not clear whether the data will help ignite public interest in boosters. Only about 10 percent of people 5 and older in the United States has received a bivalent booster, according to CDC data.
To measure the effect of the additional shot, the scientists compared the antibodies that block the virus in the blood of 511 people, before and after the bivalent booster or the original one. What cannot be predicted from these laboratory experiments is how much or how long higher levels of antibodies will protect people from serious infections or illnesses. Most scientists expect the boosters will help protect against the worst outcomes but will not provide strong protection against infection.
Moderna reports that its bivalent booster creates five to six times the antibody levels compared to older boosters. It is a strong advantage of the effect of the bivalent booster previously set to the fight BA.1 variant. But some scientists question whether the differences between the two groups of people who received each type of shot may be partially responsible for some of the benefits.
On the contrary, Novavax, a late in the vaccine racebe given data last week suggesting that the bivalent booster of his shot that includes the omicron BA.1 subvariant does not offer an advantage over the original booster.
The company did not present data on the bivalent BA.4 / BA.5-containing vaccine, but argued that the original shot could continue to offer protection, instead of updating the formula. It is not clear why there were different results. Novavax’s chief medical officer, Filip Dubovsky, said last week that the company’s shot may have led to a broader response to the variant, which was then reinforced by a repeat of the older formulation. Unlike the widely used messenger RNA vaccines from Pfizer-BioNTech and Moderna, the Novavax shot is protein based vaccine with additional substances called adjuvants designed to stimulate the immune system.
Novavax has said it may update its shot if required by regulatory agencies.
“We are ready to respond to whatever is needed,” Dubovsky said. “But we actually think that we have a case to stick with what we have now, and it seems to be working now, is the way forward.”