A recent study published at the Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report (MMWR) assessed the effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primary vaccination, an additional initial dose, or a booster injection against SARS-CoV-2 infection Omicron in the nursing home.
SARS-CoV-2-related morbidity and deaths are common among occupants of nursing homes. These were priority populations for early vaccination against COVID-19. In reports of reductions in vaccine-induced immunity against CoV disease 2019 (COVID-19) following initial vaccination, i.e. two primary doses of a messenger ribonucleic acid (mRNA) vaccine ) (mRNA-1273 or BNT162b2) or a primary Ad26.COV2 vaccine, the CDC has advised everyone 12 years of age or older to receive a booster dose of the SARS-CoV-2 vaccine. In addition, an additional dose of primary vaccination against SARS-CoV-2 is also advised for severely or moderately immunocompromised people, mainly consisting of many occupants of nursing homes.
Nevertheless, there is limited information on the vaccine efficacy (VE) of additional initial or booster doses of the SARS-CoV-2 vaccine against COVID-19 in residents of nursing homes, primarily against highly transmissible variants of the virus. SARS-CoV-2 Omicron.
About the study
In the current study, researchers analyzed weekly SARS-CoV-2 vaccination coverage and surveillance data among nursing home residents provided to the CDC’s National Healthcare Safety Network (NHSN) by nursing home facilities. Skilled Nursing Care (SNF) February 14 to March 27, 2022 The SARS-CoV-2 Omicron variant was found in over 99% of isolates sequenced during the study period.
The authors aimed to determine the comparative VE against COVID-19 for any SARS-CoV-2 booster or additional initial dose compared to primary series vaccination after controlling for calendar week and variance between SNFs by assessing SARS vaccination -CoV-2 and surveillance data from over 15,000 SNFs.
Each week, nursing facilities accredited by the Centers for Medicaid & Medicare Services (CMS) have reported one confirmed COVID-19 incident among staff and occupants to NHSN based on their vaccination status. Case data from CMS-certified SNFs was used in this investigation. Only close contacts of a resident or staff member infected with SARS-CoV-2 were assessed in SNFs with contact tracing capabilities. The vaccination status of infected persons was divided into four categories: 1) main series only, 2) booster or additional dose, 3) not vaccinated and 4) other (unspecified vaccination or received an injection of mRNA vaccine).
The weekly census of residents by vaccination status was also reported weekly by the FNS. In addition, the average number of weekly residents, by vaccination status, for each SNF was used to calculate residents/weeks. The authors compared weekly COVID-19 cases representing vaccination status in each SNF two weeks prior to weekly resident rates by vaccination status.
According to the study results, the comparative VE of a SARS-CoV-2 booster or an additional primary dose was particularly substantial compared to the primary serial vaccination after accounting for variations between SNFs and the calendar week. These data suggest that supplemental primary or booster doses of COVID-19 provide significant protection against Omicron-variant infections in nursing residents compared to initial series vaccination alone.
From February 14 to March 27, 2022, 15,090 SNFs submitted 89,671 weekly COVID-19 case count reports, while 15,102 SNFs submitted 89,969 weekly resident count reports from January 31 to March 13, 2022 The search incorporated 85,494 records from 14,758 SNFs after matching SNF-weekly SARS-CoV-2 infections with associated resident data and applying exclusion criteria. The median weekly population count documented was 1,126,198, with approximately 22% receiving only the main series of vaccines and 65% receiving an additional primary or booster dose. Additionally, among nursing home occupants who received a series of primary vaccinations, an additional initial injection, or a booster dose, more than 90% received mRNA-based COVID-19 vaccines.
Confirmed weekly crude rates of COVID-19 decreased in all nursing home vaccination cohorts over the research period. Nonetheless, the rates of SARS-CoV-2 infection among occupants who received a booster or supplemental primary dose were significantly lower than those of unvaccinated residents or residents who received only the primary vaccine. series.
Approximately 7,510 confirmed cases of COVID-19 out of 1,509,674 residents/weeks were reported among residents who received only a primary vaccination, while 11,334 confirmed cases of SARS-CoV-2 were reported between 4 416,401 residents/weeks in which a booster or extra dose was reported. Additionally, the adjusted comparative VE against COVID-19 for the additional booster or primary doses versus the single vaccine in the initial vaccination series was 46.9%.
Study findings illustrated that a booster or extra dose of SARS-CoV-2 primary vaccine gave higher protection against COVID-19 than only serial primary immunization during Omicron variant prevalence in occupants of nursing homes. The authors recommended that all nursing home residents with compromised immunity receive an additional primary dose of COVID-19 vaccine and, if eligible, a booster dose to protect against infection with the COVID-19 vaccine. SARS-CoV-2. They also cautioned that other SARS-CoV-2 prevention techniques, such as vaccination and screening of care home visitors and staff, should be used alongside initiatives to keep home occupants knowledgeable about COVID-19 vaccination.
Additionally, the study suggested that the efficacy and durability of booster or supplemental main doses against the evolution of SARS-CoV-2 variants should be assessed by continuously monitoring their VE among residents of nursing homes. .