COVID vaccine hesitancy linked to traffic crashes

People who refused to be vaccinated against COVID-19 appear to be at significantly greater risks of a traffic accident, reports a study.

“A greater awareness of traffic risks might encourage patients to take protective actions for personal safety,” said the researchers, led by Dr Donald A Redelmeier from Sunnybrook Health Sciences Centre, Toronto, Canada.

Redelmeier and his team conducted a population-based longitudinal cohort analysis of adults by determining the COVID vaccination status using electronic medical records. They also defined traffic crashes requiring emergency medical care by multicentre outcome confirmation of all hospitals throughout the region over the subsequent year.

A total of 11,598,549 individuals were identified, of whom 1,210,754 did not receive a COVID vaccine. During the 1-year follow-up interval, 54,558 adults got injured in traffic crashes, equivalent to a risk of 4,704 per million. [Am J Med 2024;137:227-235.E6]

People who had not been vaccinated had a 58-percent higher traffic risk than those who had received a COVID vaccine (6,983 vs 4,438 per million; p<0.001).

“The increased traffic risks among unvaccinated individuals included diverse subgroups, were accentuated for single-vehicle crashes, extended to fatal outcomes, exceeded the risks associated with sleep apnea, and persisted after adjustment for baseline characteristics,” Redelmeier said.

Analyses using artificial intelligence techniques, adjusted for several confounders, validated these increased risks, which were generally higher than those of other adverse effects (eg, myocarditis) normally attributed to COVID vaccination.

“Together, these findings are more powerful than earlier studies, stronger than typical traffic safety science, and arguably more rigorous than usual postmarketing surveillance of medications,” according to Redelmeier and colleagues.

Mitigating risks

Although some adults might not be open to COVID vaccination, such choice could put them at increased risks of traffic incidents. [J Community Health 2022;47:237-245]

These traffic risks are “sustained, serious, and sometimes lethal,” according to the researchers. “The reasons for increased traffic risks are not fully apparent, and the magnitudes of increased risks are generally larger than typical adverse events frequently ascribed to COVID vaccination.”

Several strategies that could be implemented to reduce traffic risks included the following: respecting speed limits, yielding right-of-way, signaling turns, minimizing distractions, avoiding tailgating, wearing a seatbelt, and no drinking of alcoholic beverage. [CMAJ 2014;186:118-124]

“An increased awareness of traffic risks might encourage patients to take protective action for their own self-defense,” the researchers said.

The current study was limited by the absence of data on the responsibility for a crash. Some traffic accidents have been caused by another person. While this may be the case, a previous study showed that unvaccinated adults were at especially higher risks of single-vehicle events. [Traffic Inj Prev 2012;13:219-229]

Additionally, late-night collisions are usually prone to driving errors and are greater among individuals who had not been vaccinated. [Accid Anal Prev 2009;41:522-530]

“A lack of direct data distinguishing responsibility or blame is customary in medical science, yet is unlikely to explain the findings,” Redelmeier said. [Int J Epidemiol 2016;45:1668-1675]