A bivalent COVID-19 vaccine by Moderna that targets two coronavirus variants has been approved by the UK’s MHRA for adult booster doses
According to a press release from the MHRA, an updated version of the COVID-19 vaccine made by Moderna and which targets two coronavirus variants (known as a “bivalent” vaccine) has now been approved for use as a booster dose for adults in the UK.
In each dose of the updated vaccine, ‘Spikevax bivalent Original/Omicron’, half of the vaccine targets the original COVID-19 strain from 2020 and the other half (25 micrograms) targets Omicron. The current MHRA approval was based on the findings of a phase 2/3 trial, which is available as a pre-print in which the bivalent vaccine was compared to the authorised 50-µg mRNA-1273 booster in adults who previously received 2-dose primary series of 100-µg mRNA-1273. Earlier work with the bivalent COVID-19 vaccine had shown that it elicited a higher neutralising antibody response against the ancestral (or original) COVID-19 and the Beta variant than that after the second mRNA‑1273 dose (i.e., the original Moderna vaccine), as well as against the Omicron and Delta variants.
Clinical efficacy of the Bivalent COVID-19 booster
In the latest pre-print study, the bivalent COVID-19 booster was examined in a group of 437 individuals with a mean age of 57.3 years (41% male) and compared with a group of 377 patients (mean age, 57.5 years, 49.3% male), who received the mRNA-1273 (50 µg) vaccine. The interim analysis is based on data 28 days after the booster vaccine doses. The results showed that the bivalent COVID-19 booster dose neutralising geometric mean titres (GMT) against Omicron were 2372.4 compared to 1473.5 for the mRNA-1273. Additionally, the bivalent COVID-19 booster induced a more potent neutralising antibody response against omicron sub-variants BA.4/BA.5 and and higher binding antibody responses against alpha, beta, gamma, delta and omicron variants.
The authors of the pre-print concluded that the bivalent booster elicited a superior neutralising antibody response against omicron, compared to mRNA-1273, and potent neutralising antibody responses against the BA.4 and BA.5 omicron sub-variants, 28 days after immunisation.
Commenting on the approval, Dr June Crown, the MHRA chief executive said
“The first generation of COVID-19 vaccines being used in the UK continue to provide important protection against the disease and save lives. What this bivalent vaccine gives us is a sharpened tool in our armoury to help protect us against this disease as the virus continues to evolve.’
Although the bivalent COVID-19 booster is yet to be approved by the EMA, the organisation announced in June that has started a rolling review of the vaccine.