AHN study shows older, immunocompromised patients account for most COVID-19 hospitalizations among those who are fully vaccinated

(PITTSBURGH, Pa.) Clinical trials and observational studies show that all COVID-19 vaccines authorized in the U.S. are extremely effective at preventing severe disease, hospitalizations and deaths associated with COVID-19. Hospitalizations, however, do occur among a small number of those who are fully vaccinated, and immunocompromised patients are at highest risk, according to a new study by infectious disease physicians at Allegheny Health Network (AHN).

With limited data available regarding such patients, AHN infectious disease specialists Matthew Moffa, DO, Nathan Shively, MD, and Thomas Walsh, MD, sought to better understand their characteristics and clinical outcomes. The team facilitated a study last summer of fully vaccinated patients who had been hospitalized with COVID-19 at eight AHN hospitals across western Pennsylvania. The study findings were recently published on behalf of Infectious Diseases Society of America in the medical journal Open Forum Infectious Diseases.

Included in the study were 473 inpatients treated at AHN hospitals over a period of approximately six weeks. Of those patients, 128 were fully vaccinated, but none had received a booster vaccine as these vaccines were not yet authorized at the time of the study. The remaining patients were either unvaccinated or did not receive a full vaccine course.

Among the fully vaccinated and hospitalized patients, nearly 90 percent were 65 years or older and/or severely immunocompromised, meaning they were being treated for cancer, had a prior organ transplant or stem cell transplant, or they were on medications to suppress their immune system.

About half of those who were fully vaccinated required intensive critical care, and 19 of the patients died. No fully vaccinated patient under the age of 50 required mechanical ventilation or died from COVID-19.

“Our experience at AHN underscores that while the vaccines are extremely effective in preventing hospitalization and death, some people are at risk despite being fully vaccinated, especially those who are medically vulnerable,” said Dr. Moffa. “Getting fully vaccinated and boosted, nevertheless, is still the most important thing anyone can do to avoid getting sick or severely ill with COVID-19, and to help prevent the spread of the virus to other vulnerable people.”

To schedule an appointment at AHN to obtain the COVID-19 vaccine and booster, visit www.ahn.org/coronavirus/vaccine.