A high-powered group of scientists employed at Beth Israel Deaconess Medical Center and Los Alamos National Laboratory submitted some correspondence to the New England Journal of Medicine declaring more challenges with the current mass vaccination program targeting Covid-19.
Reminding that the Omicron BA.5 variant was the predominant strain in circulation from July to November 2022, there was evidence of “substantial neutralization escapes as compared with previous variants.” This variant was followed by ensuing sublineages such as BA.4.6 as well as mutations from BA.5, including BF.7 and BQ.1.1, and mutations derived from BA.2.75.2 and the BA.2 lineages, including recombinant XBB.1.
What’s in common with these variants? They all have the R346T mutation in the spike protein. Now, BQ.1.1 and XBB.1 have replaced the one dominant BA.5 around the globe. It’s not clear yet, however, how well these latest mutations evade vaccine-induced antibodies targeting the spike protein of both the original Wuhan variant and BA.5.
Enter the Study
The group of scientists embarked on a study to evaluate the neutralizing antibodies associated with the Covid-19 vaccines. The first study focused on 16 participants who were vaccinated as well as boosted with the monovalent mRNA vaccine BNT162b2 (Pfizer-BioNtech) in 2021.
The team includes tables including A) Spike Protein Sequence Mutations for Subvariants and B-D including the following:
- Neutralizing antibody titers before and after receipt of the monovalent mRNA booster 2021
- Neutralizing antibody titers before and after receipt of the monovalent mRNA booster 2022
- Neutralizing antibody titers before and after receipt of the bivalent mRNA booster 2022
Summary of findings
In the first investigation, the group looked at neutralizing antibody titers before and after receipt of the monovalent mRNA booster 2021 in 16 subjects finding:
“The median neutralizing antibody titers to the BQ.1.1 and XBB.1 variants were lower than the median titer to BA.5 by factors of 3 and 8, respectively.”
Study number two and three centered on neutralizing antibody titers before and after receipt of the monovalent mRNA booster as well as the bivalent booster in 2022. With 15 and 18 participants, respectively, a majority of the subjects had received three previous doses of the Covid-19 vaccine.
A third of the participants were infected with Omicron, but this was likely due to the high prevalence of circulation and ensuing infection in 2022.
“The median neutralizing antibody titers to the BQ.1.1 and XBB.1 variants were lower than the median titers to BA.5 by factors of 7 and 17, respectively, in the monovalent booster cohort and by factors of 7 and 21, respectively, in the bivalent booster cohort.”