There is widespread belief that bivalent covid vaccines have not been tested on humans, such that Global News felt obliged to set the record straight on September 2, 2022.
Aaron D’Andrea’s highlights two controversies:
existence of human trial data for bivalent vaccines - Moderna has human data; what about Pfizer?
—>It appears that there is no human trial data for Pfizer bivalent.
Which variants are contained within bivalent vaccines - does Moderna’s use of old omicron variants matter for efficacy?
—>Regarding whether “ variants matter,” Mr. D’Andrea reports:
Health Canada said in its approval declaration Thursday that “exploratory analyses” suggests a second booster shot with Moderna’s BA.1 bivalent vaccine could provide a superior neutralizing antibody response against BA.4 and BA.5 compared to a second booster with the original shot.
Omicron variants in bivalent shots: Moderna: Omicron BA1. Pfizer: BA4 and BA5
3 Questions:
1. should a covid vaccine match for variants that are currently circulating?
Is this possible, given how rapidly new variants appear?
3. what is meant by “ exploratory analyses?” Is this clinical trial data? Is this unvetted data coming directly from the vaccine manufacturers themselves?
TIMELINE OF OMICRON VARIANTS BA1,4, and 5
When did BA1, BA4, and BA5 appear? Can we infer when these variants are likely to give way to some other variant? How similar are these variants to one another?
There is a global variant website, covariants.org, which displays data on which covid variants are most prevalent at any point in time.
Omicron BA1 disappeared in May 2022 (21K above). It was the dominant variant for 3-4 months. Omicron BA4 (aka 22B) stopped circulating at the end of August. It never dominated, but was significant for 5 months. Omicron BA5 (22C) began circulating in early June. Presumably it will dominate for 3 to 5 months before disappearing in October or November.
Meanwhile, another variant is rising in prominence, Omicron BA4.6. The CDC has a data tool demonstrating this (simpler/less detailed than covariants site).
I conclude trying to deploy a covid vaccine for a particular variant is nearly impossible, as variant dominance has a duration of 3 to 5 months. A recent CBC interview with Dr. Anthony Fauci touched on this problem, with Dr. Fauci expressing very mild enthusiasm regarding whether it would be possible to design, test, rejig, distribute , and administer covid variant vaccines on the timeline that the covid virus’ rate of mutation creates.
Does producing a vaccine for a non-circulating virus make sense?
Will Moderna’s BA1 vaccine effective, or Pfizer’s, once BA5 disappears in late 2022?
It appears we are asked to believe two contradicting hypotheses:
Covid vaccines need to be “updated” due to new variants
It is ok to use a Covid vaccine based on old variants
These questions are only the tip of the iceberg when it comes to Covid vaccines and their logic. However, given that it is proposed by Moderna, Pfizer, the FDA, and the CDC that no further rigorous research on bivalents or future Covid vaccines is needed, it is important to acknowledge to just what degree we are flying from the seat of our pants.