Pollution Tied to Risk for Serious COVID-19 Despite Vaccination

Exposures to PM_2.5 and NO₂ linked to increased risk for COVID-19-related hospitalization, with and without adjustment for vaccination

FRIDAY, Oct. 7, 2022 (HealthDay News) — Regardless of vaccination status, exposure to air pollution is associated with an increased risk for COVID-19 hospitalization, according to a letter to the editor published online Oct. 3 in the American Journal of Respiratory and Critical Care Medicine.

Zhanghua Chen, Ph.D., from the Keck School of Medicine at the University of Southern California in Los Angeles, and colleagues conducted a study involving 50,010 individuals aged 12 years and older with COVID-19 from July 1, 2021, to Aug. 31, 2021, to examine the associations of long- and short-term exposure to nitrogen dioxide (NO₂), fine particles (PM_2.5), and ozone with COVID-19-related hospitalizations.

The researchers found that 34.0 and 4.2 percent of participants were fully and partially vaccinated before COVID-19 diagnosis. Overall, 6.1 percent had COVID-19-related hospitalization within 30 days after COVID-19 diagnosis. Vaccination significantly reduced the risk for hospitalization, with adjusted odds ratios of 0.46 and 0.16 for partially and fully vaccinated, respectively, compared with unvaccinated, after adjustment for covariates and air pollutants. With and without adjustment for vaccination status, exposures to PM_2.5 and NO₂ were associated with an increased risk for COVID-19-related hospitalization (adjusted odds ratios for one standard deviation increase, 1.17 and 1.13 for one-month PM_2.5 and NO₂, respectively, and 1.25 and 1.19 for one-year PM_2.5 and NO₂, respectively, without adjustment for vaccination status); the odds ratios of hospitalizations associated with PM_2.5 and NO₂ were increased slightly with adjustment for vaccination status.

“While COVID-19 vaccines are successful at reducing the risk of hospitalization, people who are vaccinated and exposed to polluted air are still at increased risk for worse outcomes than vaccinated people not exposed to air pollution,” a coauthor said in a statement.

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