Effectiveness of BNT162b2 and ChAdOx-1 vaccines in residents of long-term care facilities in England using a time-varying proportional hazards model

Abstract

Introduction residents of long-term care facilities (LTCFs) are at high risk of adverse outcomes from SARS-CoV-2. We aimed to estimate the vaccine effectiveness (VE) of one and two doses of BNT162b2 and ChAdOx-1 against SARS CoV-2 infection and COVID-19-related death in residents of LTCFs. Methods this observational study used testing, vaccination and mortality data for LTCF residents aged ≥ 65 years who were regularly tested regardless of symptoms from 8 December 2020 to 30 September 2021 in England. Adjusted VE, calculated as one minus adjusted hazard ratio, was estimated using time-varying Cox proportional hazards models for infection and death within 28 days of positive test result. Vaccine status was defined by receipt of one or two doses of vaccine and assessed over a range of intervals. Results of 197,885 LTCF residents, 47,087 (23.8%) had a positive test and 11,329 (5.8%) died within 28 days of a positive test during the study period. Relative to unvaccinated individuals, VE for infection was highest for ChAdOx-1 at 61% (40–74%) at 1–4 weeks and for BNT162b2 at 69% (52–80%) at 11–15 weeks following the second dose. Against death, VE was highest for ChAdOx-1 at 83% (58–94%) at 1–4 weeks and for BNT162b2 at 91% (75–97%) at 11–15 weeks following second dose. Conclusions compared with unvaccinated residents, vaccination with one dose of BNT162b2 or ChAdOx-1 provided moderate protection against infection and death in residents of LTCFs. Protection against death improved after two doses. However, some waning of protection over time was noted.

Evaluation of COVID-19 vaccine effectiveness in different high-risk facility types during a period of Delta variant dominance in the Republic of Korea: a cross-sectional study

“…In contrast, group B showed an effectiveness rate of 63.4% for preventing severe disease and 57.7% for preventing fatalities. These findings align with those of previous studies conducted in the United Kingdom [ 23 ] and further emphasize the strong protective effects of COVID-19 vaccination among older adults residing in day care centers and long-term care facilities. The differences in VE between groups A and B may have been influenced by various factors, including population characteristics, infection control measures, and healthcare resources specific to each setting [ 24 ].…”

Effectiveness of Second mRNA COVID-19 Booster Vaccine in Immunocompromised Persons and Long-Term Care Facility Residents

“…The immunogenicity in immunocompromised persons might be lower than that in immunocompetent persons; however, the second booster dose clearly provides additional protection in this population (14). The relatively low VE against all infections seems to be consistent with previous studies that examined VE in LTCFs; however, its effectiveness against severe infection or death was relatively sustained, as observed elsewhere (15,16). During the observation period, we saw no clear evidence of waning against critical infection or death >30 days after the second booster (Appendix, https://wwwnc.cdc.gov/EID/ article/28/11/22-0918-App1.pdf).…”

Long-term effectiveness of COVID-19 vaccines against infections, hospitalisations, and mortality in adults: findings from a rapid living systematic evidence synthesis and meta-analysis up to December, 2022

“…We screened 16 696 records at the title and abstract level, appraised 832 (5·0%) full texts, and initially included 73 (0·4%) studies. Of these, we excluded five (7%) studies because of critical risk of bias, 20 , 21 , 22 , 23 , 24 leaving 68 (93%) studies that were extracted for analysis ( appendix p 16 ).…”