Meanwhile, both Moderna and Pfizer/BioNTech have presented encouraging preliminary results of trials with an Omicron-targeted shot.

The French and British partners last week presented data from their clinical trial with a bivalent D614 and Beta (B.351) vaccine candidate and said their candidate was the first to demonstrate efficacy in a placebo-controlled trial in an environment of high Omicron variant circulation. The shot showed a favorable safety and tolerability profile, they added

In a trial with 13,000 participants, the Sanofi/GSK their vaccine was seen to be 64.7% effective against symptomatic Covid-19 generally, but efficacy rose to 72% in confirmed symptomatic cases of infection with omicron. In February, the drugmakers reported 58% efficacy against symptomatic infection with the original strain and 77% efficacy against the Delta variant.

To date, Sanofi and GSK said they have sequenced 71 out of 121 Covid cases. Efficacy was found to be higher in participants previously infected. In that group, the vaccine achieved 75.1%.overall efficacy against symptomatic infection but the figure rose to 93.2% in participants who had had confirmed symptomatic cases of omicron.

The two companies hope that, pending regulatory approval, they will have a product on the market in this year’s second half. Sanofi is banking on a full analysis of the data indicating the potential of the next-generation beta-based booster to be a “relevant response” to public health needs.

Thomas Triomphe, executive vice president Vaccines at Sanofi, said the results reinforce the strong potential for the Beta antigen to confer broad protection against multiple strains that cause Covid-19.  “While mRNA has proven speed to market, we are demonstrating here the efficacy that our recombinant protein platform can provide to the world,” he said.

For its original Covid-19 vaccine research, Sanofi received project aid
from the US Biomedical Advanced Research and Development Authority (BARDA), which steers the country’s rapid response to emergencies. After its first candidate fell behind competitors, the drugmaker began toll-manufacturing BioNTech’s RNA-based vaccine at one of its plants in Frankfurt, Germany.

BioNTech/Pfizer and Moderna log better response to Omicron

BioNTech and Pfizer have also reported a “significantly larger immune response” for their new Omicron-targeted Covid-19 vaccine compared with their original vaccine. The companies said on Jun. 25 that this modified booster increased neutralizing antibody levels 13.5 to 19.6 times higher than the current shot.

A booster targeting both Omicron and the original virus strain increased neutralizing antibody levels 9.1 to 10.9 times, depending on the dose, and both of the tweaked candidates were well tolerated, the German-American duo said.

“Based on these data, we believe we have two very strong Omicron-modified candidates that elicit a substantially higher immune response against Omicron than we’ve seen to date,” Pfizer CEO Albert Bourla said.

While the not yet peer reviewed study did not measure efficacy, Pfizer and BioNTech said early lab testing showed that the modified vaccines were also effective against Omicron sub-variants BA.4 and BA, though they generated about three times lower antibody levels against Omicron sub-variants than against the original Omicron strain.  The companies said they are still collecting data on the sub-variants.

Moderna also has reported that its newest Covid-19 vaccine produces a stronger immune response against major variants, including Omicron and Delta, compared to the shot currently administered. The bivalent vaccine contains mRNA coding for the spike protein of both the original strain of and the Omicron strain.

CEO Stèphane Bancel said Moderna's Covid-19 variant vaccine should be ready to ship in August, as the company has been producing ahead of approval.  The biotech said earlier it hoped to roll out the shot in Europe and North America by autumn.

The US Food and Drug Administration (FDA) has been holding public hearings to determine which strains of the coronavirus should be included in US booster shots this autumn and who should receive them. The next meeting will be held on Jun. 28 to deliberate on how the strain compositions should be modified.

The health agency meanwhile has approved Moderna’s Covid vaccine for six-to-19 year-olds, after earlier greenlighting Pfizer-BioNTech’s. It also recently approved both the Moderna and Pfizer-BioNTech shots for children aged five and younger, despite reservations about efficacy in that age group. Reports said US parents had been clamoring for a shot to be made available.

Author: Dede Williams, Freelance Journalist