Florida adults who received Pfizer’s COVID-19 vaccine were more likely to die following vaccination than Moderna COVID-19 recipients, according to a new preprint study that was co-authored by Florida’s top health official.

Dr. Joseph Ladapo, Florida’s surgeon general, and other researchers identified nearly 9.2 million Florida adults not living in institutions who received at least two doses of the Pfizer or Moderna vaccine less than six weeks apart between Dec. 18, 2020, and Aug. 31, 2021.

They narrowed the group to nearly 1.5 million, half who received Pfizer’s vaccine and half who received Moderna’s vaccine, by matching them based on criteria such as age and sex. They then analyzed the records to see which group had the higher risk for all-cause mortality, or death from any cause, in the 12 months following vaccination.

That analysis found that more Pfizer recipients died, with 847 deaths per 100,000 recipients, compared to 618 deaths per 100,000 for Moderna recipients. Pfizer recipients were also more likely to suffer heart-related deaths and COVID-19 deaths.

Pfizer and Moderna did not respond to requests for comment.

Two other employees of the Florida Department of Health are listed as co-authors for the new study.

Both Ladapo and Retsef Levi, a professor at the Massachusetts Institute of Technology and the fourth author, have called previously for the suspension of the Pfizer and Moderna COVID-19 vaccines over what they’ve described as alarming findings in various studies.

Limitations of the paper included the matching process reducing the size of the studied population and not including co-morbidities, according to the researchers.

They said their study is different in part because the size of the population studied is bigger and the matching is more precise.

Critics of the study questioned why it did not also compare the vaccinated to the unvaccinated.