Thread by @michaelzlin

Novavax announced their vaccine protects adolescents from Delta infection by 80% (95% CI, 47-92%) after dose 2 vs placebo. Side effects were stated as similar or milder than adults.

Short thread to put in context

prnewswire.com/news-releases/…

To compare to RNA vaccines, we can look at Pfizer results. In one study Pfizer protection was 91% at week 3 after dose 2. It appears in the high 80s at week 2 and 4. medpagetoday.com/infectiousdise…

Another study had Pfizer protection at 93% between weeks 1 and 3. So Novavax appears close, maybe the same (difference is well within the CI). Antibody levels are higher with Novavax in adults so you might have expected better VE.
nejm.org/doi/full/10.10…

Novavax says reactogenicity (side effect profile) in adolescents is similar or milder than adults. The same was said for Pfizer (cdc.gov/vaccines/covid…). Then we can compare adult side effect distributions below

We can focus on the most common side effects of fatigue and fever. For both Novavax and Pfizer, these are more common after dose 2. Placebo-subtracted fatigue rate is 25% for Novavax, 37% for Pfizer. Placebo-subtracted fever is 4% Novavax, 15% Pfizer. (Again, old adult data)

Teen rates of vaccination are only 57% in the US, lower than older ages. So there's a lot of room for improvement.
news.northeastern.edu/2022/02/08/chi…

While we still don't know about rare side effects like myocarditis (due to low n), it may be useful to have Novavax as an option for nervous parents who can be reassured that it is a protein + adjuvant formulation similar to annual flu vaccines and other childhood vaccinations.

Forgot to mention, the Novavax press release didn't specify the length of the follow-up period after vaccination. Given small number of participants it's likely longer than 4 weeks, so the Pfizer numbers may not be directly comparable.