BNT162b2 mRNA Vaccine Effectiveness Given Confirmed Exposure: Analysis of Household Members of Coronavirus Disease 2019 Patients
This article has been Reviewed by the following groups
Listed in
- Evaluated articles (ScreenIT)
Abstract
Background
Although BNT162b2 vaccine-efficacy analyses have been published, the effectiveness of the vaccine in preventing coronavirus disease 2019 given confirmed exposure has not been previously demonstrated, even though it has policy implications, such as the need for self-quarantine when exposure has occurred.
Methods
In a retrospective cohort study, we used data collected between 20 December 2020 and 17 March 2021 from the second largest healthcare provider in Israel to analyze the probability of an additional household infection occurring within 10 days after an index infection. In model 1, vaccine effectiveness was described for Fully Vaccinated individuals (7 or more days from second dose) vs either Unvaccinated individuals or those Recently Vaccinated Once (0–7 days from the first dose, presumably still unprotected). Secondary analyses included correction for differing testing rates. In model 2, we conducted a separate analysis of households comprised of only adults with the same vaccination status.
Results
A total of 173 569 households were included, of which 6351 had an index infection (mean [standard deviation] age, 58.9 [13.5] years); 50% were women. Adjusted vaccine effectiveness of Fully Vaccinated compared with Unvaccinated participants was 80.3% (95% confidence interval [CI], 73.5–85.4) and 82.0% (95% CI, 75.6–86.8) compared with those Recently Vaccinated Once.
Conclusions
The BNT162b2 vaccine is effective in high-risk real-life exposure scenarios, but the protection afforded in these settings is lower than that previously described. Individuals with a confirmed significant exposure to severe acute respiratory syndrome are still at risk of being infected even if fully vaccinated.
Article activity feed
-
-
SciScore for 10.1101/2021.06.29.21259579: (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
Software and Algorithms Sentences Resources All statistics were performed using Python version 3.1 with the stats models package. Pythonsuggested: (IPython, RRID:SCR_001658)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:Our study has several limitations. All data are observational, therefore testing was not performed with the use of a strict clinical protocol. Therefore, testing was less likely to be performed …
SciScore for 10.1101/2021.06.29.21259579: (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
Software and Algorithms Sentences Resources All statistics were performed using Python version 3.1 with the stats models package. Pythonsuggested: (IPython, RRID:SCR_001658)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:Our study has several limitations. All data are observational, therefore testing was not performed with the use of a strict clinical protocol. Therefore, testing was less likely to be performed for vaccinated household members and asymptomatic cases may have been missed. We did not include data on viral strains. We assumed that all exposure within a given household posed a high risk of transmission, but we are unable to quantify the actual level of exposure with a given household. The large sample size, high vaccination rates, high testing rates, and correction performed for missing testing all partly overcome these limitations. Household studies are certainly an efficient way of assessing vaccine effectiveness in a given population6,19–22, allowing for analyses of infection rates when exposure is confirmed with a high degree of certainty – thus avoiding the potential skewing effect of intrinsic differences amongst communities. Additionally, there is a high likelihood that the same SARS-CoV-2 strain infected persons living in the same household. Two issues are the subject of our future research, currently underway; first, the inclusion of more than two household members in general and of children in particular. Transmission dynamics could be influenced by age, and children are more likely to be asymptomatic and less likely to be tested. Children may also affect of the magnitude of exposure as they increase the number of persons per household12. “Quantifying” exposure relative...
Results from TrialIdentifier: No clinical trial numbers were referenced.
Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).
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.
- No protocol registration statement was detected.
Results from scite Reference Check: We found no unreliable references.
-
