The immune responses against Omicron BA.4/BA.5 subvariants were “significantly higher,” according to Pfizer and BioNTech, in individuals who received its new bivalent booster compared to individuals who received the companies’ original Covid-19 vaccination.
Early in September, the US saw the availability of the bivalent booster, which works against both the original coronavirus strain and the Omicron BA.4 and BA.5 subvariants. According to a press statement from Pfizer and BioNTech, compared to the original vaccine, the bivalent booster produced roughly four times as much neutralising antibody against the Omicron BA.4/BA.5 variants in persons over the age of 55. The data has not been published or subjected to peer review.
It may take a few weeks for a vaccination to fully protect a person after it has been administered. The research showed that Omicron BA.4/BA.5 neutralising antibodies increased 13.2 fold from pre-booster levels for individuals 55 and older a month after trial participants received the new booster, compared with a 2.9 fold increase in older persons who received the original vaccine. Neutralizing antibodies were 9.5-fold greater than pre-booster levels in people between the ages of 18 and 55.
Since July, US Covid-19 infections have been dominated by the Omicron BA.5 subvariant, but a variety of other Omicron subvariants have been gaining ground on it. According to information from the US Centers for Disease Control and Prevention, BA.5 is now responsible for 49.6% of new infections in this nation.
As we approach the holiday season, Pfizer CEO Albert Bourla said in a statement, “We hope that these updated data will encourage people to seek out a COVID-19 bivalent booster as soon as they are eligible in order to maintain high levels of protection against the widely disseminated Omicron BA.4 and BA.5 sublineages.” These revised data also give us confidence in our mRNA platform’s versatility and our capacity to quickly modify the vaccine to correspond to the most common strains each season.
The modified Covid-19 booster shots appear to function about as effective against the BA.4 and BA.5 Omicron subvariants as the original boosters they replaced, according to two small studies that assessed immune responses three to five weeks following the updated booster dosage. The papers have not undergone peer review or been published; they were made available as preprints.
Pfizer and BioNTech said they are continuing to test the vaccine against more virus strains while also conducting larger clinical studies of the upgraded boosters.
Even for those who have already been exposed to an infection or have had a vaccination, experts say being boosted this fall is still a crucial approach to renewing protection. Updated boosters are available to people as young as five.
Updated Covid-19 boosters have been given to 26.3 million Americans aged 5 and older so far.
According to a study published at the beginning of October, if more Americans received the booster before the end of the year, about 90,000 Covid-19 deaths may be avoided this fall and winter. According to a study from the Commonwealth Fund, the US may experience a peak of more than 1,000 Covid-19 deaths per day this winter if vaccination uptake kept up at the rate of early October.
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