Omicron-targeted Covid-19 vaccines from Pfizer and BioNTech are eliciting a strong immune response, significantly outperforming their previous vaccine in fighting the most prevalent variant, according to new data.
The US drugmaker and its German partner said on Saturday they plan to discuss the data with global regulators, who will meet next week to discuss coordinating a move to new vaccines that target the Omicron strain of virus.
The companies created two booster vaccines: a monovalent Omicron-targeted and a bivalent, which contained the original strain and the genetic code of the Omicron variant. The single-strain vaccine caused a 13.5-fold increase in neutralizing antibodies at the lowest dose and a 19.6-fold increase at a higher dose. The two-strain vaccine increased antibody levels between 9.1 and 10.9 times.
Preliminary laboratory studies have demonstrated that the new injections also neutralize the rapidly spreading Omicron BA subvariants. 4 and BA. 5, although to a lesser extent than for the original BA. 1 Omicron variant.
Albert Bourla, chief executive of Pfizer, said the data suggested the companies had two very strong candidates for widespread use. “We look forward to discussing this data with the scientific community and health authorities so that we can rapidly introduce an Omicron-modified booster as soon as possible if cleared by regulators,” he said.
On Tuesday, advisers from the U.S. Food and Drug Administration are due to discuss which strains of the virus the next generation of boosters should target as they prepare to roll out new vaccines in late summer or fall.
Moderna last week urged regulators to clear its new bivalent booster which contains the genetic code of the original strain and Omicron, saying it has demonstrated a “potent neutralizing antibody response” to BA subvariants. 4 and BA.5.
Moderna’s bivalent booster elicited an eight-fold increase in antibodies to fight the Omicron variant compared to pre-booster levels, when given as part of a four-dose regimen. He produced 1.75 times more antibodies than those found in people who received a booster shot of Moderna’s existing vaccine, according to his trial, which is not directly comparable to the BioNTech/Pfizer trial.
BioNTech/Pfizer’s monovalent vaccine candidate – which is specifically designed to target the original Omicron variant – produced a better immune response than its bivalent vaccine, which combines its existing vaccine with one targeting the spike protein of the Omicron variant.
A 60 microgram dose of the monovalent jab caused an almost 20-fold increase in neutralizing antibodies against BA. 1 Variant of Omicron from pre-booster levels, when administered as part of a four-dose regimen. A smaller 30-microgram dose of the same vaccine boosted antibody levels 13.5-fold, according to a clinical study of 1,234 participants aged 56 or older.
Pfizer said the 60 microgram dose produced an immune response three times higher than the existing BioNTech/Pfizer vaccine.
In contrast, the bivalent vaccine showed a 10.9-fold increase in antibodies over pre-booster levels, when given as part of a four-dose regimen.