I was very interested to read, and also somewhat surprised, that the Novavax vaccine generally has few side-effects. The reason I am surprised is that the Novavax vaccine contains an adjuvant made from saponins derived from the bark of a Chilean tree,
Quillaja saponaria. The Shingrix vaccine also contains an adjuvant derived from the same tree, and that adjuvant was thought to be the reason why side-effects from Shingrix tend to be stronger than other vaccines. The adjuvant is also thought to be an important part of why Shingrix has a high efficacy. Shingrix was the first human vaccine to use an adjuvant from
Quillaja saponaria. I believe that the Shingrix and Novavax adjuvants are not 100% identical, but both contain saponins from the same tree bark. The Novavax adjuvant apparently contains 2 molecules isolated from the tree bark. One of those molecules is in the Shingrix vaccine. I believe that Novavax patented their adjuvant,
"Matrix-M", which contains other molecules as well.
I had a severe reaction from my 1st Shingrix dose (complete deafness in one ear, fortunately reversed thanks to prompt treatment with an oral steroid). My primary care physician, as well as two friends who are physicians, all told me to not get the 2nd Shingrix dose, and I followed their advice. My PCP also put an entry in my electronic medical record stating that I am "allergic" to Shingrix. Because of my experience with Shingrix, I decided that I would not have gotten the Novavax vaccine had it been available to me. That didn't stop me from getting vaccinated with the Pfizer vaccine, which was the first Covid vaccine I was able to get. I had minimal side effects to all 3 Pfizer doses I've now received, and I've never had any strong side effects to any other vaccine, including Zostovax, the earlier, less effective, shingles vaccine.
Here's an interesting article about the adjuvant in the Novavax vaccine, as well as information about the Chilean plant.
https://www.reuters.com/business/he...ope-new-vaccines-if-supplies-last-2021-10-06/