When the delta variant of the coronavirus hit the Sierra Conservation Center – a low to medium security prison for men in California – residents who had received the Moderna vaccine were well protected against symptomatic infections, according to research conducted by Stanford.
The study, published in The New England Journal of Medicine, also found that in men who had previously been infected with COVID-19, two doses of the Moderna vaccine resulted in additional and substantial protection against the delta variant.
The study is one of the first to analyze the effectiveness of vaccination during an outbreak of the delta variant. The researchers found that although the estimated efficacy of the vaccine against infection (56.6%) was significantly lower than that found in studies conducted before the emergence of the delta variant, protection against symptomatic infection remained. high (84.2%). And in men who had previously had COVID-19, the vaccine reduced the risk of subsequent infection by 80.5%.
The study also noted that at the height of the pandemic, incarcerated people were infected with the coronavirus at a rate five times higher than the general population of the country.
Even though we detected a high efficacy of the vaccine in our study, the epidemic underlines that incarcerated people continue to face the risks of the COVID-19 pandemic. Relying on immunization alone is insufficient to prevent epidemics in this vulnerable population. “
Elizabeth Chin, lead author of the study and PhD candidate in Biomedical Data Science
Chin stressed that prison authorities must prioritize not only efforts to increase immunization coverage among their residents and staff, but also to step up non-pharmaceutical strategies such as masking, testing and downsizing. the population and density of their penitentiary establishments, taking into account the highly transmissible variants.
Chin is a member of a team of researchers who used mathematical modeling and data analysis throughout the pandemic as part of the Prevention Policy Modeling Lab and the SC-COSMO consortium. They modeled and analyzed COVID-19 data to inform prevention and mitigation strategies across the country, including in California and its prisons. For this study, the researchers collaborated with colleagues from the California Department of Corrections and Rehabilitation and California Correctional Health Care Services.
Chin, AND, et al. (2021) Effectiveness of mRNA-1273 vaccine during a SARS-CoV-2 Delta outbreak in a prison. The New England Journal of Medicine. doi.org/10.1056/NEJMc2114089.