People who have received COVID-19 vaccines are more likely to get infected than those who are unvaccinated, according to two new studies.
Cleveland Clinic PaperIn their paper, a preprint published by medRxiv, Cleveland Clinic researchers analyzed data from clinic employees to arrive at estimates of vaccine effectiveness. The retrospective cohort study looked at data from Sept. 12, when the new boosters became available, through Dec. 12.
“A simplistic explanation might be that those who received more doses were more likely to be individuals at higher risk of COVID-19. A small proportion of individuals may have fit this description. However, the majority of subjects in this study were generally young individuals and all were eligible to have received at least 3 doses of vaccine by the study start date, and which they had every opportunity to do,” wrote the researchers, including Dr. Nabin Shrestha.
“Therefore, those who received fewer than 3 doses (>45% of individuals in the study) were not those ineligible to receive the vaccine, but those who chose not to follow the CDC’s recommendations on remaining updated with COVID-19 vaccination, and one could reasonably expect these individuals to have been more likely to have exhibited higher risk-taking behavior. Despite this, their risk of acquiring COVID-19 was lower than those who received a larger number of prior vaccine doses.”
The researchers noted that multiple other studies, including the Qatari paper, have offered similar results.
“We still have a lot to learn about protection from COVID-19 vaccination, and in addition to a vaccine’s effectiveness it is important to examine whether multiple vaccine doses given over time may not be having the beneficial effect that is generally assumed,” they said.
Researchers did not look at the effectiveness against severe illness or hospitalization.
No funding sources for the study were listed. Under “funding,” researchers listed, “none.”
“It’s important to note that the study was done in a younger, relatively healthy, healthcare employee population. It included no children, very few elderly individuals and likely few immunocompromised individuals. Therefore, we urge caution in generalizing the findings to the public, which can include different populations than was in this study,” a spokesperson for the clinic told The Epoch Times via email.
“The study found that the longer it has been since last exposure to the virus by infection or vaccination, the higher the risk of acquiring COVID-19. It also found that the higher the number of vaccine doses an individual previously received, the higher the risk of contracting COVID-19. It is unclear at this time why this was observed and how it should be interpreted, and more research is needed to either confirm or refute this finding. It’s important to note that this paper has not yet been peer reviewed.”
Indiana PaperThe Indiana researchers, including Dr. Shaun Grannis of the Regenstrief Institute, combed statewide testing and vaccination data as well as medical records to match individuals to compare incidence of infection, emergency department visits, hospitalizations, and deaths. The observational study, which only included people aged 12 and older with at least one previously recorded health care encounter with the Indiana Network for Patient Care between Jan. 1, 2016, and early 2022, crunched data from between Nov. 29, 2020, and Feb. 9, 2022.
The researchers estimated the incidence of COVID-19 was higher among the vaccinated when compared with the unvaccinated but naturally immune. Six months after the index date—30 days after an initial infection or 30 days after a vaccination—the cumulative infection rate was 6.7 percent among the vaccinated and just 2.9 percent among the previously infected. The rate remained higher among the vaccinated in all age groups when the results were stratified by age.
The study also concluded that the vaccinated were better protected than the naturally immune against emergency department visits, hospitalizations, and mortality.
“The findings highlight the real-world benefits of vaccination and allude to the health consequences of SARS-CoV-2 after the initial exposure,” Grannis and his co-authors wrote.
The paper was published by the American Journal of Public Health, which is the publication of the American Public Health Association. No funding sources were listed.