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Cited by 76SARS-CoV-2 and COVID-19 ResearchCOVID-19 epidemiological studiesVaccine Coverage and Hesitancy

Identifying and Alleviating Bias Due to Differential Depletion of Susceptible People in Postmarketing Evaluations of COVID-19 Vaccines

Open access
Kahn, Rebecca, Schrag, Stephanie J, Verani, Jennifer R, Lipsitch, Marc·2022·American Journal of Epidemiology
DOI 10.1093/aje/kwac015PMC PMC8807238

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Abstract

Recent studies have provided key information about SARS-CoV-2 vaccines’ efficacy and effectiveness (VE). One important question that remains is whether the protection conferred by vaccines wanes over time. However, estimates over time are subject to bias from differential depletion of susceptible individuals between vaccinated and unvaccinated groups. We examined the extent to which biases occur under different scenarios and assessed whether serological testing has the potential to correct this bias. By identifying nonvaccine antibodies, these tests could identify individuals with prior infection. We found that in scenarios with high baseline VE, differential depletion of susceptible individuals created minimal bias in VE estimates, suggesting that any observed declines are likely not due to spurious waning alone. However, if baseline VE was lower, the bias for leaky vaccines (which reduce individual probability of infection given contact) was larger and should be corrected for by excluding individuals with past infection if the mechanism is known to be leaky. Conducting analyses both unadjusted and adjusted for past infection could give lower and upper bounds for the true VE. Studies of VE should therefore enroll individuals regardless of prior infection history but also collect information, ideally through serological testing, on this critical variable.

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Sorted by citations

Authors
Kahn, R., Schrag, S. J., Verani, J. R., & Lipsitch, M.
Corresponding author
Kahn, Rebecca
ORCID
Venue
American Journal of Epidemiology
Publisher
Oxford University Press (OUP)
Published
2022-01-27
Volume
191
Issue
5
Pages
800-811
ISSN
  • 0002-9262 (ISSN-L)
  • 1476-6256
DOI
10.1093/aje/kwac015
PMC
PMC8807238
OpenAlex
W4207056100
Cited by
76
References
5
Citations by year
2026: 6 · 2025: 10 · 2024: 17 · 2023: 27 · 2022: 13 · 2021: 3
FWCI
8.18
Type
journal article
Language
en
Open access
Licence
public-domain
Locations
  • American Journal of Epidemiology (publishedVersion, public-domain)
  • medRxiv (acceptedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • ImmPort
Funders
  • National Institutes of Health
  • National Cancer Institute (U01CA261277)
  • National Institute of General Medical Sciences (R01GM139926)
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
  • Social Sciences › Health › Vaccine Coverage and Hesitancy
Keywords
COVID-19 vaccines, vaccine effectiveness, waning immunity, bias correction, serological testing, prior SARS-CoV-2 infection, post-marketing surveillance, SARS-CoV-2
MeSH terms
COVID-19, SARS-CoV-2, COVID-19 Vaccines, Disease Susceptibility, Humans, Vaccines, Bias

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