Background:
On March 11, 2020 the World Health Organisation declared the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causing Coronavirus Disease 2019 (COVID-19) syndrome, as a pandemic. The UK mass vaccination programme commenced on December 08, 2020 vaccinating groups of the population deemed to be most vulnerable to severe COVID-19 infection.
Objective:
To assess the early vaccine administration coverage and outcome data across an integrated care system in North West London (NWL), leveraging a unique population-level care dataset. 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 08, 2020 and February 24, 2021 within a primary, secondary and community care integrated care dataset. These data were used to assess vaccination hesitancy across ethnicity, gender and socio-economic deprivation measures (Pearson Product-Moment Correlations); investigated COVID-19 transmission related to vaccination hubs; and assessed 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 the 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% (4,337/26,870). There was a strong negative association between socio-economic deprivation and rate of declining vaccination (r=-0.94, P=.002) with 13.5% (1980/14571) of individuals declining vaccination in the most deprived areas compared to 0.98% (869/9609) in the least. In the first six days after vaccination 344 of 389587 individuals tested positive for SARS-CoV-2 (0.09%). 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% (HR 0.26 (0.19-0.35)) and 78% (HR 0.22 (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 (0.01% 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 roll-out in NWL, and the risk of contracting COVID-19 and/or becoming hospitalised after vaccination has been demonstrated to be very 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.