Sanofi and GSK have jointly developed a next-generation COVID-19 booster vaccine candidate, based on Sanofi’s recombinant Beta variant antigen and combined with GSK’s pandemic adjuvant. Both have served as established vaccine platforms that have proven successful against influenza.
In the phase 3 VAT02 cohort 2 trial, the Sanofi/GSK vaccine candidate caused – at day 15 post-immunisation – a significant boost in antibody titres above baseline against multiple variants of concern in adults who previously received mRNA COVID-19 vaccinations.
Specifically against Omicron, the preliminary data demonstrated 40 times as much of an increase against the BA.1 variant.
In addition to this, the Sanofi/GSK booster produced twice the number of neutralising antibodies against Omicron BA.1 and BA.2 when compared to the original parent virus booster.
Thomas Triomphe, executive vice president, Sanofi Vaccines, said: “COVID-19 keeps evolving and the combination of emergence of variants and waning immunity is likely to lead to the need for additional booster shots, at least in some populations. The Beta variant expresses similar mutations across multiple variants of concern, including Omicron, making it a strong vaccine candidate to confer broad protection against multiple strains of COVID-19.
“Seeing the cross-neutralisation data from the independent AP-HP study, we believe this next-generation booster could have an important role to play for public health vaccination campaigns. We look forward to submitting the data to global regulatory authorities.”
The independent COVIBOOST study showed that, following a primary vaccination with two doses of Pfizer/BioNTech’s Comirnaty vaccine, the Sanofi/GSK booster resulted in a higher immune response than Pfizer/BioNTech’s booster or the Sanofi/GSK first-generation booster, both targeting the original D614 parent strain.
The COVIBOOST trial, conducted by Assistance Publique, Hôpitaux de Paris, involved 247 participants and reported that all three vaccines elicited neutralising antibodies against the Omicron BA.1 strain, with the highest responses coming from the Sanofi/GSK booster.
Both studies showed the Sanofi/GSK next-generation vaccine was well-tolerated, with a favourable safety profile, while in the VAT02 cohort 2 study, less than 4% of grade 3 reactions were reported, all noted as being transient and non-severe.
The partnership plans to submit the data to regulatory authorities in the coming weeks, with the goal of making it available later in 2022.