A flu shot could reduce the severe effects of COVID-19, new research suggests. An analysis of data from tens of thousands of patients with coronavirus found that people who received a flu shot experience fewer serious health problems.
According to a large study, people vaccinated against the flu may be partially protected from some of the severe consequences of the coronavirus and are less likely to need urgent care, The Guardian writes.
An analysis of data from nearly 75,000 COVID-19 patients found significant reductions in strokes, deep vein thrombosis and sepsis, as well as fewer hospital admissions to emergency departments and intensive care units among those receiving flu shots.
While the flu vaccine did not reduce deaths from the coronavirus according to this study, previous research suggests that the flu shot may provide some protection against coronavirus by boosting the innate immune system – the body’s overall defenses that do not target a specific pathogen.
Another explanation is possible, notes The Guardian: patients who received the flu vaccine may have better overall health than those who did not receive the vaccine.
“We found an association that appears to show that influenza vaccination offers some protection against the severe illness of COVID-19,” said Devinder Singh, senior study author and professor of clinical surgery at the University of Miami.
If the findings are supported by further research, they may be most valuable for countries that have not been able to compete with richer countries for COVID vaccines and where the burden of influenza and coronavirus together threatens to overburden health services.
“It is very important to emphasize that we absolutely recommend the COVID-19 vaccine and in no way suggest that the influenza vaccine is a substitute for the proper COVID-19 vaccine,” says Professor Singh.
Researchers compared the electronic health records of 37,377 coronavirus patients from the UK, US and other countries who had received flu shots to a similar number of patients who had not been vaccinated against the flu. Patients in the two groups were similar in age, gender, ethnicity, health problems including diabetes and lung disease, and lifestyle factors such as diet and smoking.
The researchers analyzed how often patients suffered from any of 15 potentially serious health consequences, from blood clots and heart attacks to kidney and respiratory failure, within four months of being diagnosed with COVID.
The results, presented at an online meeting of the European Society of Clinical Microbiology and Infectious Diseases, suggest that an influenza vaccine may protect against some of the medical problems caused by the coronavirus. According to the study, COVID patients who were not vaccinated against influenza were 45–58% more likely to have a stroke, about 40% more likely to suffer from deep vein thrombosis, and 36–45% more likely to have sepsis. In addition, they were more likely to be admitted to the intensive care unit and more likely to be admitted to emergency departments.
“It may happen that the influenza vaccine non-specifically stimulates the immune system and has this advantage, but you always wonder if these associations are causal or if there is a common factor such as social deprivation that may explain why they go hand in hand. – says Professor Peter Openshaw, member of the Government Advisory Group on Threats of New and Emerging Respiratory Viruses (Nervtag). “People who manage to get the flu shot can improve their health in other ways.”
“The best way to protect yourself from COVID is to get a COVID vaccine,” the scientist added.