People living in communities with high COVID-19 vaccination rates record fewer deaths from the virus, a new US study has found.
The findings, which are published in today’s edition of *The BMJ*, are based on data across 2,558 counties in 48 US states and show that counties with high vaccine coverage had a more than 80% reduction in death rates compared with largely unvaccinated counties.
By 11 April 2022, more than 11 billion COVID-19 vaccine doses had been administered globally and the World Health Organization’s (WHO) target is to vaccinate 70% of the world’s population by mid-2022.
Previous vaccine studies have shown benefits at the individual level, but little was known about the wider population level impact of scaling up Cid-19 vaccination.
Researchers at the US Centers for Disease Control and Prevention (CDC) examined more than 30 million cases of COVID-19 and more than 400,000 deaths linked to the virus across 2,558 counties, which were reported between December 2020 and December 2021.
They compared reported COVID-19 incidence and mortality rates in counties with vaccination rates that were very low (0-9%), low (10-39%), medium (40-69%), and high (70% or more) in adults who had received at least one dose.
After taking account of potentially influential factors, the team found that increased vaccination coverage in counties was associated with reduced levels of COVID-19 cases and death.
During the first half of 2021, when the alpha variant was dominant, the COVID-19 mortality rate was reduced by 60%, 75%, and 81% in counties with low, medium, and high vaccination coverage, respectively, compared with counties that had very low coverage.
The corresponding figures for the reduction in cases were 57%, 70%, and 80%.
Similar figures were recorded in the second half of 2021 with the prominence of the delta variant, although there were smaller effects on case levels.
Although this is an observational study, and the researchers point to a number of limitations, they say their results were similar after further sensitivity analyses.
“Future research may benefit from evaluating macroeconomic effects of improving population health, such as changes in employment rates and gross domestic product resulting from reopening society,” they add.
Suthar A, Wang J, Seffren J et al. Public health impact of COVID-19 vaccines in the United States: observational study. *BMJ* 28 April 2022; doi: 10.1136/bmj 2021 069317
Leave a Reply