ABSTRACT
BackgroundA rapid increase in cases due to the SARS-CoV-2 Omicron (B.1.1.529) variant in highly vaccinated populations has raised concerns about the effectiveness of current vaccines. MethodsWe used a test-negative case-control design to estimate vaccine effectiveness (VE) against symptomatic disease caused by the Omicron and Delta variants in England. VE was calculated after primary immunisation with two BNT162b2 or ChAdOx1 doses, and at 2+ weeks following a BNT162b2 booster. ResultsBetween 27 November and 06 December 2021, 581 and 56,439 eligible Omicron and Delta cases respectively were identified. There were 130,867 eligible test-negative controls. There was no effect against Omicron from 15 weeks after two ChAdOx1 doses, while VE after two BNT162b2 doses was 88.0% (95%CI: 65.9 to 95.8%) 2-9 weeks after dose 2, dropping to between 34 and 37% from 15 weeks post dose 2.From two weeks after a BNT162b2 booster, VE increased to 71.4% (95%CI: 41.8 to 86.0%) for ChAdOx1 primary course recipients and 75.5% (95%CI: 56.1 to 86.3%) for BNT162b2 primary course recipients. For cases with Delta, VE was 41.8% (95%CI: 39.4-44.1%) at 25+ weeks after two ChAdOx1 doses, increasing to 93.8% (95%CI: 93.2-94.3%) after a BNT162b2 booster. With a BNT162b2 primary course, VE was 63.5% (95%CI: 61.4 to 65.5%) 25+ weeks after dose 2, increasing to 92.6% (95%CI: 92.0-93.1%) two weeks after the booster. ConclusionsPrimary immunisation with two BNT162b2 or ChAdOx1 doses provided no or limited protection against symptomatic disease with the Omicron variant. Boosting with BNT162b2 following either primary course significantly increased protection.
ABSTRACT
In England, the National Immunisation Management System (NIMS) has been used to deliver COVID-19 vaccinations across England, monitor vaccine coverage, and assess vaccine effectiveness and safety. The NIMS was developed by a joint collaboration between a range of health and digital government agencies. Vaccinations delivered at large vaccination sites, pharmacies, hospitals and in primary care are entered on a point of care application which is verified using the unique NHS number in a centralised system containing information for everyone resident and registered with a GP in England. Vaccination details and additional data from hospital and GP records (such as priority groups) are sent to NHS Digital for data linkage. The NIMS constantly receives updated details from NHS Digital for all individuals and these data are provided to Public Health England (PHE) in a secure environment. PHE primarily use the NIMS for vaccine coverage, vaccine effectiveness and safety. Daily access to individual-level vaccine data has allowed PHE to rapidly and accurately estimate vaccine coverage and provide some of the worlds first vaccine effectiveness estimates. Other countries evaluating the roll-out and effect of COVID-19 vaccine programmes should consider a vaccine register or immunisation information system similar to the NIMS.
ABSTRACT
ObjectiveTo determine characteristics associated with COVID-19 vaccine coverage among individuals aged 50 years and above in England since the beginning of the programme. DesignObservational cross-sectional study assessed by logistic regression and mean prevalence margins. SettingCOVID-19 vaccinations delivered in England from 08 December 2020 - 17 May 2021. Participants30,624,257/ 61,967,781 (49.4%) and 17,360,045/ 61,967,781 (28.1%) individuals in England were recorded as vaccinated in the National Immunisation Management System with a first dose and a second dose of a COVID-19 vaccine, respectively. InterventionsVaccination status with COVID-19 vaccinations. Main Outcome MeasuresProportion, adjusted odds ratios and mean prevalence margins for individuals not vaccinated with dose 1 among those aged 50-69 years old and dose 1 and 2 among those aged 70 years old and above. ResultsAmong individuals aged 50 years and above, Black/African/Caribbean ethnic group was the least likely of all ethnic groups to be vaccinated with dose 1 of the COVID-19 vaccine. However, among those aged 70 years and above, the odds of not having dose 2 was 5.53 (95% CI 5.42 to 5.63) and 5.36 (90% CI 5.29 to 5.43) greater among Pakistani and Black/African/Caribbean compared to White British ethnicity, respectively. The odds of not receiving dose 2 was 1.18 (95% CI 1.16 to 1.20) higher among individuals who lived in a care home compared to those who did not. This was the opposite to that observed for dose 1, where the odds of not being vaccinated was significantly higher among those not living in a care home (0.89 (95% CI 0.87 to 0.91)). ConclusionsWe found that there are characteristics associated with low COVID-19 vaccine coverage. Inequalities, such as ethnicity are a major contributor to suboptimal coverage and tailored interventions are required to improve coverage and protect the population from SARS-CoV-2. Article summaryO_ST_ABSStrengths and Limitations of this studyC_ST_ABSO_LIThis is the is the first study assessing characteristics associated with COVID-19 vaccine coverage for all individuals aged 50 years and above in England. C_LIO_LIThis study uses data from the National Immunisation Management System (NIMS) which is based on all individuals in England with a registered NHS number. C_LIO_LIThis centralised national system captures individual level data for both vaccination status and demographic characteristics and allows for linkage to other datasets such as health care worker and care home resident status. C_LIO_LIThis study does not include those without an NHS number and, therefore, it is possible we have underestimated the number of vaccines delivered and odds of not being vaccinated for characteristics such as ethnic groups where we have seen the greatest impact. C_LIO_LIResidual errors in data entry on the point of care apps at the vaccination sites may have also occurred, though these errors are not likely to be widespread. C_LI
