High air pollution hits Covid vaccine response: Study

The research team measured three kinds of antibodies (IgM, IgG and IgA) to five viral antigens (three of them on the spike protein contained in the vaccine).

Increasing levels of air pollution can lower Covid-19 vaccine responses, said a new study, highlighting fresh dangers posed by the noxious air that several Indian cities breathe.

A woman gets a booster dose of the Covid-19 vaccine in Srinagar.(PTI)

Higher levels of PM2.5, NO2 and black carbon were associated with a 5% to 10% decrease in vaccine antibody responses among individuals without prior infection, said the study, published in the open access journal Environmental Health Perspectives.

The team analysed data from 927 participants aged 40 to 65 who answered questionnaires and submitted blood samples in the summer of 2020 and the spring of 2021. All of them received one or two doses of the primary Covid-19 vaccines administered in Spain, made by AstraZeneca, Pfizer or Moderna.

The research team measured three kinds of antibodies (IgM, IgG and IgA) to five viral antigens (three of them on the spike protein contained in the vaccine).

Each participant’s exposure to PM2.5, black carbon, NO2 and ozone (O3) was estimated based on their location and address before the pandemic broke out.

“The collaboration of all volunteers in the cohort, with more than 10 years of data, has allowed us to reliably estimate the level of environmental exposure of all participants,” said Rafael de Cid, co-author of the study.

The decrease in antibodies was shown both for early IgM responses and late responses measured by IgG, the researchers said.

The IgG response after the first dose peaked later in participants exposed to higher levels of air pollution, even as lower IgG levels persisted for several months after a participant took the jab.

Results were similar for all three vaccines.

The fact that previous infections lead to higher vaccine responses could explain why the effect of pollutants was only observed in people without a prior infection, said the researchers.

However, the role of long-term exposure to air pollution on hybrid immunity (infection plus vaccination) deserves further investigation, they added.