ArticleStatistics in medicine2021
Assessing vaccine durability in randomized trials following placebo crossover.
Article in Statistics in medicine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers, 1 of them a synthesis that pooled it.
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The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
18 citing papers in PubMed, 1 synthesis or guideline pooled it.
- A Deferred-Vaccination Design to Assess Durability of COVID-19 Vaccine Effect After the Placebo Group Is Vaccinated.Annals of internal medicine · 2021Pooled it
- Validating and leveraging non-SARS-CoV-2 respiratory infection as a negative control outcome in a phase 3 COVID-19 vaccine trial with extended observational follow-up.American journal of epidemiology · 2026Trial
- Durability of Protection Against COVID-19 Through the Delta Surge for the NVX-CoV2373 Vaccine.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2024Trial
- Estimating vaccine efficacy during open-label follow-up of COVID-19 vaccine trials based on population-level surveillance data.Epidemics · 2024Trial
- A simple and powerful test of vaccine waning.American journal of epidemiology · 2026Article
- Exposure proximal immune correlates analysis.Biostatistics (Oxford, England) · 2025Article
- Review
- Designs for Vaccine Studies.Annual review of statistics and its application · 2025Article
- Who to Boost When: The Effect of Age and Dosing Interval on Delta and Omicron COVID-19 Incidence in the Open-label Phase of the COVE Trial.Open forum infectious diseases · 2024Article
- Safety, effectiveness and immunogenicity of heterologous mRNA-1273 boost after prime with Ad26.COV2.S among healthcare workers in South Africa: The single-arm, open-label, phase 3 SHERPA study.PLOS global public health · 2024Article
- Estimating Waning of Vaccine Effectiveness: A Simulation Study.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2023Article
- Rapid Development of an Integrated Network Infrastructure to Conduct Phase 3 COVID-19 Vaccine Trials.JAMA network open · 2023Article
- Article
- Discussion on "Estimating vaccine efficacy over time after a randomized study is unblinded" by Anastasios A. Tsiatis and Marie Davidian.Biometrics · 2022Article
- Article
- Estimation of vaccine efficacy for variants that emerge after the placebo group is vaccinated.Statistics in medicine · 2022Article
- Durability of Protection Against Symptomatic COVID-19 Among Participants of the mRNA-1273 SARS-CoV-2 Vaccine Trial.JAMA network open · 2022Article
- Assessing vaccine durability in randomized trials following placebo crossover.Statistics in medicine · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Randomized vaccine trials are used to assess vaccine efficacy (VE) and to characterize the durability of vaccine-induced protection. If efficacy is demonstrated, the treatment of placebo volunteers becomes an issue. For COVID-19 vaccine trials, there is broad consensus that placebo volunteers should be offered a vaccine once efficacy has been established. This will likely lead to most placebo volunteers crossing over to the vaccine arm, thus complicating the assessment of long term durability. We show how to analyze durability following placebo crossover and demonstrate that the VE profile that would be observed in a placebo controlled trial is recoverable in a trial with placebo crossover. This result holds no matter when the crossover occurs and with no assumptions about the form of the efficacy profile. We only require that the VE profile applies to the newly vaccinated irrespective of the timing of vaccination. We develop different methods to estimate efficacy within the context of a proportional hazards regression model and explore via simulation the implications of placebo crossover for estimation of VE under different efficacy dynamics and study designs. We apply our methods to simulated COVID-19 vaccine trials with durable and waning VE and a total follow-up of 2 years.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.