The annual flu shot may protect against some of the most severe effects of COVID-19 and the need for emergency care, according to research presented July 11 during the European Congress of Clinical Microbiology & Infectious Diseases.
Researchers from the University of Miami analyzed the health records of 37,377 patients who received the flu shot two to six months before contracting COVID-19. They matched the group to the same number of COVID-19 patients who didn't get the flu vaccine. Patients were from the U.S., U.K., Germany, Israel and Singapore.
The research team analyzed the incidence of the following adverse outcomes: sepsis; strokes; deep vein thrombosis; pulmonary embolism, acute respiratory failure, acute respiratory distress syndrome; arthralgia or joint pain; renal failure; anorexia; heart attack; pneumonia; and emergency department visits.
Overall, COVID-19 patients who were not vaccinated against the flu were up to 20 percent more likely to be admitted to the intensive care unit.
Findings showed they were also up to 58 percent more likely to visit the emergency room, up to 45 percent more likely to develop sepsis, up to 58 percent more likely to have a stroke, and up to 30 percent more likely to experience DVT. Researchers did not observe a difference in death risk between the two study groups.
Researchers can't determine exactly how the flu shot may offer protection against severe COVID-19 effects, though expect it's related to the way the shot activates the immune system.
"This finding is particularly significant because the pandemic is straining resources in many parts of the world," said Devinder Singh, MD, senior study author and plastic surgery professor at the University of Miami Miller School of Medicine. "Therefore, our research — if validated by prospective randomised clinical trials — has the potential to reduce the worldwide burden of disease."