The news is out that the FDA has authorized mix & matching COVID-19 vaccines for boosting! The CDC is meeting today to discuss recommendations around this topic. I have posted before on some mix & match data (previous #explainthatdata posts) but this latest set of data (currently pre-print) was conducted in the US (10 clinical sites) with the 3 vaccines used here (J&J, Moderna, and Pfizer).
The paper enrolled 458 individuals who had previously been fully vaccinated with one of the 3 vaccines at least 12 weeks prior (J&J: 156, Moderna: 151, Pfizer: 151). They were then given a booster dose, equally divided among the 3 once again. This produced 9 different groups, 3 of which represent homologous vaccination (same primary and booster), while 6 groups are different combinations of heterologous vaccination (different primary and booster).
Overall it was found that no matter your primary dose, an mRNA-based vaccine booster will produce the best response. While I did not discuss the reactogenicity data, it was found to be similar to what was reported for the primary series.
This data is exciting and encouraging! I have long felt that mixing & matching would work well. Authorizing it would increase flexibility ultimately improving accesibility.
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The numbers in the above heatmap table were calculated the following way:
Day 15 Nab value / Day 1 Nab value = Fold Increase in Nab
Fold increase for homologous group / Fold increase in heterologous group = how much better heterologous option was compared to homologous option
I keep seeing this illustration being posted on Facebook. What is the citation of the study?
Hi! Thanks for the question. The citation is listed in the bottom left-hand corner of the image (very small print)! I also have a links tab here on this website and if you scroll to the bottom you will find a list of all the “Explain That Data” posts that I do and this one titled “How much better is mixing and matching?” will be the last one listed. It will take you straight to the pre-print!
Thanks so much! This is the clearest breakdown of advantages/disadvantages of booster mix&matches I’ve seen. But I’m still wondering if these results were based on a 100% Moderna dose or the 50% Moderna booster that’s been rolled out to the public? Thank you again!
Appreciate the feedback! This was done with the 100% (100ug) dose of Moderna.
https://www.medrxiv.org/content/10.1101/2021.10.10.21264827v1.full.pdf