A: Boosters with the original Pfizer and Moderna vaccines increase protection against the omicron variant…NOW.
A few weeks ago we posted on results from Pfizer showing that:
🔵 A third dose of the original Pfizer vaccine increased neutralizing antibody titers against the omicron variant by 25-fold, compared to levels seen with only two doses
🔵 The level of neutralizing antibodies against the omicron variant seen after three doses, was also similar to the level produced against the original SARS-CoV-2 virus after two doses
🔵 Levels of CD8+ T cells against spike protein epitopes which correlate with protection against severe disease were also increased, and 80% of these epitopes that are recognized by CD8+ T cells remain unchanged with the omicron variant
Yesterday, Moderna released results showing that:
🔵 A third dose of 50 mcg of the original Moderna vaccine increased neutralizing antibodies against omicron 37-fold, compared to the levels seen with two doses
🔵 A third dose of 100 mcg of the original Moderna vaccine increased neutralizing antibodies against omicron to an even greater extent (by 83-fold, compared to the levels seen with two doses) and was well tolerated in terms of side effects
These results are good signs 👍 that a third dose of the Pfizer or Moderna vaccine provides solid protection against the omicron variant. Even though the ability of antibodies to neutralize the SARS-CoV-2 virus have been shown to be lower for the omicron variant, having higher levels of antibodies to begin with can help offset that disadvantage. The booster can also strengthen other aspects of our immune response (such as T cells) which target parts of the virus that are less likely to mutate, which helps protect us against severe disease.
While trials of omicron-specific vaccines are in progress by both Pfizer and Moderna, results won’t be ready until early Spring, and it is unknown if it will provide better protection than the currently available vaccines. With omicron spreading quickly, getting a booster shot NOW, will get you protected sooner rather than later, so don’t wait 🏃♀️. If it has been > 6 months since your second dose, you can get the Pfizer booster if aged 16+ years, or either the Pfizer or Moderna booster if aged 18+ years.
Our previous post on the Pfizer booster and omicron
More information on the Moderna booster and omicron
A great article by Nerdy Girl in spirit, Dr. Katherine Wu, explaining why boosting now makes sense
Our previous post explaining omicron-related terms like ‘neutralizing antibodies’
