@Article{info:doi/10.2196/30010,
author="Glampson, Ben
and Brittain, James
and Kaura, Amit
and Mulla, Abdulrahim
and Mercuri, Luca
and Brett, Stephen J
and Aylin, Paul
and Sandall, Tessa
and Goodman, Ian
and Redhead, Julian
and Saravanakumar, Kavitha
and Mayer, Erik K",
title="Assessing COVID-19 Vaccine Uptake and Effectiveness Through the North West London Vaccination Program: Retrospective Cohort Study",
journal="JMIR Public Health Surveill",
year="2021",
month="Sep",
day="17",
volume="7",
number="9",
pages="e30010",
keywords="health informatics; real-word evidence; COVID-19; medical informatics; vaccine; vaccination",
abstract="Background: On March 11, 2020, the World Health Organization declared SARS-CoV-2, causing COVID-19, as a pandemic. The UK mass vaccination program commenced on December 8, 2020, vaccinating groups of the population deemed to be most vulnerable to severe COVID-19 infection. Objective: This study aims to assess the early vaccine administration coverage and outcome data across an integrated care system in North West London, leveraging a unique population-level care data set. Vaccine effectiveness of a single dose of the Oxford/AstraZeneca and Pfizer/BioNTech vaccines were compared. Methods: A retrospective cohort study identified 2,183,939 individuals eligible for COVID-19 vaccination between December 8, 2020, and February 24, 2021, within a primary, secondary, and community care integrated care data set. These data were used to assess vaccination hesitancy across ethnicity, gender, and socioeconomic deprivation measures (Pearson product-moment correlations); investigate COVID-19 transmission related to vaccination hubs; and assess the early effectiveness of COVID-19 vaccination (after a single dose) using time-to-event analyses with multivariable Cox regression analysis to investigate if vaccination independently predicted positive SARS-CoV-2 in those vaccinated compared to those unvaccinated. Results: In this study, 5.88{\%} (24,332/413,919) of individuals declined and did not receive a vaccination. Black or Black British individuals had the highest rate of declining a vaccine at 16.14{\%} (4337/26,870). There was a strong negative association between socioeconomic deprivation and rate of declining vaccination (r=--0.94; P=.002) with 13.5{\%} (1980/14,571) of individuals declining vaccination in the most deprived areas compared to 0.98{\%} (869/9609) in the least. In the first 6 days after vaccination, 344 of 389,587 (0.09{\%}) individuals tested positive for SARS-CoV-2. The rate increased to 0.13{\%} (525/389,243) between days 7 and 13, before then gradually falling week on week. At 28 days post vaccination, there was a 74{\%} (hazard ratio 0.26, 95{\%} CI 0.19-0.35) and 78{\%} (hazard ratio 0.22, 95{\%} CI 0.18-0.27) reduction in risk of testing positive for SARS-CoV-2 for individuals that received the Oxford/AstraZeneca and Pfizer/BioNTech vaccines, respectively, when compared with unvaccinated individuals. A very low proportion of hospital admissions were seen in vaccinated individuals who tested positive for SARS-CoV-2 (288/389,587, 0.07{\%} of all patients vaccinated) providing evidence for vaccination effectiveness after a single dose. Conclusions: There was no definitive evidence to suggest COVID-19 was transmitted as a result of vaccination hubs during the vaccine administration rollout in North West London, and the risk of contracting COVID-19 or becoming hospitalized after vaccination has been demonstrated to be low in the vaccinated population. This study provides further evidence that a single dose of either the Pfizer/BioNTech vaccine or the Oxford/AstraZeneca vaccine is effective at reducing the risk of testing positive for COVID-19 up to 60 days across all age groups, ethnic groups, and risk categories in an urban UK population. ",
issn="2369-2960",
doi="10.2196/30010",
url="https://publichealth.jmir.org/2021/9/e30010",
url="https://doi.org/10.2196/30010",
url="http://www.ncbi.nlm.nih.gov/pubmed/34265740"
}