My GP has written another post on vaccines, this time on the new Moderna vaccine, which has just been approved by the FDA. Click on the screenshot to read it, or you’ll likely be satisfied with the conclusions and unanswered questions below, which were remarkably similar to his take on the Pfizer vaccine.
That’s because, except for a difference in storage conditions (the Moderna vaccine requires far less cold than does the Pfizer one), the trials show both are about equally effective (94.1% for Pfizer, 95% for Moderna, which are probably not statistically significant. Both are also mRNA vaccines that inject the code for making part of the virus’s spike protein into the body, where part of the protein is made, activating antiviral antibodies, and then the mRNA is degraded. (See below for an article about how these vaccines work.) There’s a slightly higher incidents of side effects with the Moderna vaccine as well: muscle pain and joint pain after the jabs are about 20% higher for Moderna’s vaccine (an incidence of around 40%) than for Pfizer’s (incidence about 20%). But these aren’t severe side effects.
The Pfizer vaccine was tested on individuals older than 16, while Moderna’s on individuals older than 18, so efficacy in that two-year age range remains an unanswered question for Moderna.
Finally, the two doses of Moderna’s vaccine were spaced 28 days apart rather than Pfizer’s 21, but this may not be important since there seems to be a leeway of a few days. Consult your doctor.
The overall take (these quoted from the post):
- The vaccine is highly effective in preventing symptomatic COVID-19 infection.
- The vaccine is safe. Adverse reactions, both local and systemic, are mostly minor. Though the study hasn’t yet gone on long enough to prove there are no serious long-term adverse affects, such adverse affects, if they exist, are likely to be rare and non-life-threatening based on other Phase I and II studies of other RNA vaccines.
- We recommend everyone who is eligible to receive the vaccine should receive it when it becomes available to them.
- It very well may take all of 2021 to get everyone who’s willing to be vaccinated to receive the shots, which means it likely won’t be until early 2022 that life returns to pre-pandemic normal. In the meantime, continue to wear a mask when indoors with anyone you don’t live with, wash your hands frequently, and refrain from dining indoors at restaurants.
And the unanswered questions:
- While suggested by the study, still left unproven is whether BNT162b2 prevents severe COVID-19 infection, whether it prevents COVID-19 infection after just one dose, and whether it prevents COVID-19 infection in subjects who’ve already had COVID-19.
- The study didn’t look to see if the vaccine prevents asymptomatic infection. Nor did it assess whether subjects who developed COVID-19 despite vaccination are less likely to transmit the virus. Thus, it’s not yet clear how effective the vaccine will be in containing the spread of the infection.
- The study hasn’t gone on long enough to tell if subjects who were vaccinated yet still contracted COVID-19 have a lower risk of long-term effects of COVID-19.
- We don’t yet know if the vaccine reduces the risk of dying from COVID-19.
- There was insufficient data to draw conclusions about safety and efficacy of the vaccine in children younger than 18, pregnant or lactating women, and patients who are immunocompromised.
- We don’t yet know how long immunity lasts and whether or not booster shots will be necessary.
As far as which one you should take, I think Alex’s recommendation would be to take whichever one is offered to you. The news last night said that big pharmacies like CVS may well stock both types, in which case you should consult your doctor.
Here’s a new NYT article by Jonathan Corum and Carl Zimmer about how Moderna’s vaccine works (click on the screenshot; I think the article is free for all). It’s a comic-book-like series of graphics which are very good, and I’ve put a summary at the bottom.
You’ll have to click on the screenshot below, perhaps twice, if you want the whole story in one place.