A new study conducted by Aarhus University and Aarhus University Hospital showed that older people admitted to intensive care units have a lower risk of dying and suffering a blood clot or bleeding in the brain if they are vaccinated against influenza.

The data showed that those who were vaccinated had a 16% lower risk of stroke than those who were not vaccinated, as well as a group of vaccinated who had an 8% lower risk of death within the first year after their hospitalization.

“Every year 30,000 people enter intensive care units in Danish hospitals and we know that the first year is critical,” says Christian Fynbo Christiansen, clinical associate Professor at Aarhus University hospital and consultant at Aarhus University Hospital.

He continued, “three out of four survive hospitalization and are discharged from the hospital. But even among discharged patients, almost one in five dies within the first year, and many others suffer from complications. Our study shows that there are fewer deaths and serious complications among patients who have been vaccinated against flu. So it supports the current recommendation that older people should be vaccinated.”

Surprisingly, however, the vaccine “did not reduce the number of pneumonia cases in our study,” despite expectations that it would happen, as “some previous studies have shown that the vaccine has such an effect on young and healthy people.”

The study is a register-based cohort study that covered 89,818 patients who were hospitalized in intensive care units in Denmark between 2005-2015 and was supported by the Independent Research Fund Denmark and PROCRIN (the Program for Clinical Research Infrastructure).