đź’Ą In a press release earlier this week, Moderna shared a first peek at the safety and performance of their updated Omicron-inspired “bivalent” COVID-19 vaccine.
The results are encouraging, and suggest that the newer jab may provide both stronger and longer lasting protection. CEO Stéphane Bancel stated that this updated vaccine is now their lead booster candidate for the fall, and that they will soon submit data for regulatory review.
âť—While we Nerdy Girls are optimistic about the promise of this and other variant-specific vaccines, there is a lot we don’t know yet about their real-world performance. Since our current vaccines already offer excellent protection against hospitalization and death, we don’t recommend waiting around for the new shots if you’re eligible to boost now.
TL;DR:
The updated shot, dubbed mRNA-1273.214, is a two-for-one vaccine, known as a “bivalent” vaccine. The new “bivalent” shot delivers two mRNA recipes, one for the spike protein of the original SARS-CoV-2 variant, and another for the spike protein of the Omicron BA.1 variant (which differs by 32 mutations).
In a Phase 2/3 trial, the bivalent jab was tested as a fourth dose in people who had already received three previous Moderna shots (two primary shots and a booster). Volunteers received either 50 ÎĽg of the original jab or 50 ÎĽg of the new bivalent vaccine (25 ÎĽg Omicron + 25 ÎĽg original variant).
Key findings:
✅ No safety differences between the newer vaccine and the original. Per Moderna: “The mRNA-1273.214 50 μg booster dose was well-tolerated in the 437 study participants. The safety and reactogenicity profile was similar to that of mRNA-1273 50 μg dose.”
âś… Better neutralizing antibody responses to the Omicron variant, compared to the original jab, after a month. The updated booster drove an impressive 8-fold increase in Omicron-specific neutralizing antibodies a month after boosting. Levels of neutralizing antibodies against Omicron were roughly 1.75 times higher in those who got the updated, bivalent vaccine than those who got the original Moderna vaccine as their fourth shot.
âś… Higher levels of binding antibodies against all other variants of concern (Alpha, Beta, Gamma, Delta, Omicron) for the new bivalent vaccine compared to the original.
Note: Data from Moderna’s trial have not yet been made available for external scientific review.
Unknowns:
❓How well will the updated vaccine protect us against infection, 🏥 hospitalization 🏥, and death? While higher antibody counts after a month are a very good sign, we can’t perfectly predict real-world protection from antibody levels alone.
❓How long will the protection last? It’s reasonable to expect that higher antibody levels will translate to a longer lasting response, but, again, we don’t yet have enough data to draw firm conclusions. It’s also reassuring that Moderna’s Beta-inspired vaccine still showed a strong antibody response six months later, as reported in April 2022.
🙋Now what??
🦠Tailored vaccines may offer better, longer lasting protection against a wide range of variants. Yet, we still don’t know how much of an advantage they will offer in the real world, nor do we know which variants will be circulating in the fall.
🗳️ While we Nerdy Girls look forward to adding these shots to our toolbox in the fight against COVID-19, our vote is to not hold off on getting boosted. If you are eligible, seize the moment and shore up your protection by getting boosted now 💉💉💉. Our current boosters won’t make you bulletproof but they will deliver excellent protection against hospitalization and death. This likely won’t be your last shot, and you can always get an additional variant-specific booster down the line if it’s recommended.
Thanks to our resident geneticist, Nerdy Girl Chana @fueledbyscience for this post.
Links:
Should I get boosted now or wait? (Dear Pandemic)
News story on Moderna Omicron vaccine (Guardian)
Safety, Immunogenicity and Antibody Persistence of a Bivalent Beta-Containing Booster Vaccine (pre-print from Moderna, not peer-reviewed)
