In a recent study published on bioRxiv* Preprint server, researchers looked for immunological evidence why the prevalence of BQ.1.1 rose rapidly in areas where Omicron BA.5 was dominant in the United States (US).
Studies have shown that Omicron BQ.1.1 cases have risen rapidly in the US and Omicron BA.5 cases have dropped to less than half, with Omicron BA.5 recently being the dominant severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variant. Thus, it is critical to determine how BQ.1.1 evades neutralizing antibodies (nAb) induced by vaccination against coronavirus disease 2019 (COVID-19) and SARS-CoV-2 infection.
In this study, researchers evaluated nAb titers in 16 individuals who were vaccinated and boosted with the BNT162b2 monovalent mRNA vaccine in 2021. They also evaluated nAb titers in 15 individuals who received monovalent mRNA boosters in 2022. recipients, most of whom received three doses of the vaccine, although some also received two or four doses of the COVID-19 vaccine.
After a monovalent BNT162b2 booster, median nAb titers to WA1/2020, BA.5, BF.7, BA.2.75.2, and BQ.1.1 were 45, 695, 887, 595, 387, and 261, respectively. The authors noted that the mean nAb titers against BQ.1.1 were much lower than the mean nAb titers against WA1/2020 and BA.5 by a factor of 175 and 3, respectively.
Compared to the uninfected 2021 cohort, the majority were likely infected in these cohorts, although documented SARS-CoV-2 Omicron infection rates were only 33%. Also, WA1/2020 and Omicron nAb titers were higher in the two 2022 cohorts even before boosting. After boosting, their mean NAb titers on WA1/2020, BA.5, BF.7, BA.2.75.2, and BQ.1.1 were 40,515, 3693, 2399, 883, and 508, respectively.
The results of the study showed that compared to BA.5, both BA.2.75.2 and BQ.1.1 escaped nAbs elicited by prior infection and vaccination more efficiently. The effect was most pronounced for BQ.1.1, whose nAb titers were sevenfold lower than BA.5 in all study cohorts.
These findings represent an immunological explanation for the rapid increase in BQ.1.1 prevalence in areas where BA.5 was dominant in the US, with implications for both vaccine and natural immunity. It also puts into perspective how the presence of the R346T mutation in many new Omicron subvariants is likely the result of convergent evolution.
bioRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guiding clinical practice/health-related behavior, nor should they be treated as verified information.
Link to journal:
- Jessica Miller, Nicole Hachmann, Ai-ris Collier, Ninaad Lasrado, Camille Mazurek, Robert Patio, Olivia Powers, Nehalee Surve, James Theiler, Bette Korber, Dan H. Barouch. (2022). Escape of Substantial Neutralization by SARS-CoV-2 Omicron Variant BQ.1.1. bioRxiv. doi: https://doi.org/10.1101/2022.11.01.514722 https://www.biorxiv.org/content/10.1101/2022.11.01.514722v1
#SARSCoV2 #Omicrons #Latest #BQ11 #Subvariant #Shows #Extraordinary #Immune #Evasion #Potential #Vaccine #Serum