BNT162b2 Vaccination efficacy is marginally affected by the SARS-CoV-2 B.1.351 variant in fully vaccinated individuals

  1. Orna Mor
  2. Neta S. Zuckerman
  3. Itay Hazan
  4. Ronen Fluss
  5. Nachman Ash
  6. Netanel Ginish
  7. Ella Mendelson
  8. Sharon Alroy-Preis
  9. Laurence Freedman
  10. Amit Huppert

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Abstract

Background

Israeli has vaccinated over 80% of its adult population, with two doses of the Pfizer BNT162b2 vaccine. This intervention has been highly successful in curtailing the coronavirus 2 outbreak. One major concern is the ability of the virus to mutate which potentially can cause SARS-CoV-2 to partially escape from the immune system. Here we evaluate the efficacy of the Pfizer vaccine against the B.1.351 variant.

Methods

The Ministry of Health, initiated sequencing of selected positive swab samples identified as being of interest. We used logistic regression, with variant type as the dependent variable, vaccination status as the main explanatory variable, controlling for age, sex, subpopulation, place of residence and time of sample, to estimate the odds ratio for a vaccinated case to have the B. 1.351 versus the B.1.1.7 variant, within vaccinated and unvaccinated persons who tested positive.

Findings

There were 19 cases of B.1.351 variant (3.2%) among those vaccinated more than 14 days before the positive sample and 88 (3.5%) among the unvaccinated. The estimated odds ratio was 1.29 [95% CI: 0.66-2.50]. From this result, assuming the efficacy against the B.1.1.7 variant to be 95%, the estimated efficacy against the B.1.351 variant was 94% [95% CI: 87-97%].

Interpretation

Despite the concerns caused by the B.1.351 variant, the BNT162b2 vaccine seems to provide substantial immunity against both that variant and the B.1.1.7. Our results suggest that from 14 days following the second vaccine dose the efficacy of BNT162b2 vaccine is at most marginally affected by the B.1.351 variant.

Funding

No funding

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  1. ScreenIT

    SciScore for 10.1101/2021.07.20.21260833: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    NIH rigor criteria are not applicable to paper type.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Limitations of our study include the relatively low number of B.1.351 cases, owing to its low prevalence in Israel, and also the fact that the sequencing was not done on a sample selected randomly from the total population of SARS-Cov2 positive cases in Israel. In particular, samples were selected for sequencing based on a variety of concerns, but partly to check on the variants among cases occurring after vaccination and partly to follow-up on those coming into contact with persons found to have the B.1.351 variant. Thus, the database has over-representation of vaccinated cases, and also over-representation of the B.1.351 variant among cases in Israel. In order to test the robustness of our results, we used two different statistical methods, unconditional logistic regression and conditional logistic regression with matching to estimate the OR. Both analyses revealed no statistically significant difference, and indicated that any reduction in the vaccine efficacy against B.1.351 relative to B.1.1.7 is at the most marginal with an OR not exceeding 2.5. In addition, we have shown in computer simulations that this type of selection should not introduce bias into the estimation of the odds ratio of a vaccinated case having the B.1.351 variant (see Supplemental Information for details). The criterion for validly using such a database for estimating the OR is that the selection of vaccinated cases or B.1.351 cases should be independent of each other; when selecting a vaccinated cas...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a protocol registration statement.

    Results from scite Reference Check: We found no unreliable references.

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  2. Version published to 10.1101/2021.07.20.21260833 on medRxiv