In this section
@article{Williams:2024:10.1016/j.vaccine.2024.126167,
author = {Williams, LR and Emary, KRW and Phillips, DJ and Hay, J and Larwood, JPJ and Ramasamy, MN and Pollard, AJ and Grassly, NC and Voysey, M},
doi = {10.1016/j.vaccine.2024.126167},
journal = {Vaccine},
title = {Implementation and adherence to regular asymptomatic testing in a COVID-19 vaccine trial.},
url = {http://dx.doi.org/10.1016/j.vaccine.2024.126167},
volume = {42},
year = {2024}
}
TY - JOUR
AB - BACKGROUND: For pathogens which cause infections that present asymptomatically, evaluating vaccine efficacy (VE) against asymptomatic infection is important for understanding a vaccine's potential epidemiological impact. Regular testing for subclinical infections is a potentially valuable strategy but its success hinges on participant adherence and minimising false positives. This paper describes the implementation and adherence to weekly testing in a COVID-19 vaccine trial. METHODS: COV002 was a phase 2/3 trial assessing the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2. Asymptomatic infections were detected using weekly self-administered swabs for RT-PCR testing. We analysed adherence using mixed-effects regression models and estimated the probability of true and false positive asymptomatic infections using estimates of adherence and testing characteristics. FINDINGS: 356,551 tests were self-administered by 10,811 participants during the 13-month follow-up. Median adherence was 75.0% (IQR 42·6-90·9), which translated to a 74·5% (IQR 50·9-78·8) probability of detecting a positive asymptomatic infection during the swabbing period, and between 21 and 96 false positives during VE evaluation. The odds of returning a swab declined by 8% per week and further after testing positive and unblinding. Adherence was higher in older age groups, females and non-healthcare workers. INTERPRETATION: The COV002 trial demonstrated the feasibility of running a long-term regular asymptomatic testing strategy. This information could be valuable for designing future phase III vaccine trials in which infection is an outcome. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, AstraZeneca.
AU - Williams,LR
AU - Emary,KRW
AU - Phillips,DJ
AU - Hay,J
AU - Larwood,JPJ
AU - Ramasamy,MN
AU - Pollard,AJ
AU - Grassly,NC
AU - Voysey,M
DO - 10.1016/j.vaccine.2024.126167
PY - 2024///
TI - Implementation and adherence to regular asymptomatic testing in a COVID-19 vaccine trial.
T2 - Vaccine
UR - http://dx.doi.org/10.1016/j.vaccine.2024.126167
UR - https://www.ncbi.nlm.nih.gov/pubmed/39060202
VL - 42
ER -
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