A case-crossover study of the effect of vaccination on SARS-CoV-2 transmission relevant behaviours during a period of national lockdown in England and Wales. Issue 2 (9th January 2023)

• Record Type: Journal Article
• Authors: Serisier, Aimee; Beale, Sarah; Boukari, Yamina; Hoskins, Susan; Nguyen, Vincent; Byrne, Thomas; Fong, Wing Lam Erica; Fragaszy, Ellen; Geismar, Cyril; Kovar, Jana; Yavlinsky, Alexei; Hayward, Andrew; Aldridge, Robert W.
• Is Part Of: Vaccine. Volume 41:Issue 2(2023)
• Page Start: 511
• Page End: 518
• Publication Date: 2023-01-09
• Subjects: COVID-19 -- Vaccine -- Behaviour -- Mitigations; COVID-19 Coronavirus disease 2019 -- SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 -- UK United Kingdom -- IMD Index of Multiple Deprivation -- VoC Variant of Concern; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2022.11.073
• Languages: English
• ISSNs: 0264-410X

Abstract

Abstract: Background: Studies of COVID-19 vaccine effectiveness show increases in COVID-19 cases within 14 days of a first dose, potentially reflecting post-vaccination behaviour changes associated with SARS-CoV-2 transmission before vaccine protection. However, direct evidence for a relationship between vaccination and behaviour is lacking. We aimed to examine the association between vaccination status and self-reported non-household contacts and non-essential activities during a national lockdown in England and Wales. Methods: Participants (n = 1154) who had received the first dose of a COVID-19 vaccine reported non-household contacts and non-essential activities from February to March 2021 in monthly surveys during a national lockdown in England and Wales. We used a case-crossover study design and conditional logistic regression to examine the association between vaccination status (pre-vaccination vs 14 days post-vaccination) and self-reported contacts and activities within individuals. Stratified subgroup analyses examined potential effect heterogeneity by sociodemographic characteristics such as sex, household income or age group. Results: 457/1154 (39.60 %) participants reported non-household contacts post-vaccination compared with 371/1154 (32.15 %) participants pre-vaccination. 100/1154 (8.67 %) participants reported use of non-essential shops or services post-vaccination compared with 74/1154 (6.41 %) participants pre-vaccination. Post-vaccination status was associated with increased odds of reporting non-household contacts (OR 1.65, 95 % CI 1.31–2.06, p < 0.001) and use of non-essential shops or services (OR 1.50, 95 % CI 1.03–2.17, p = 0.032). This effect varied between men and women and different age groups. Conclusion: Participants had higher odds of reporting non-household contacts and use of non-essential shops or services within 14 days of their first COVID-19 vaccine compared to pre-vaccination. Public health emphasis on maintaining protective behaviours during this post-vaccination time period when individuals have yet to develop full protection from vaccination could reduce risk of SARS-CoV-2 infection.