'Repeated influenza vaccination may reduce flu severity'

Repeated vaccination for influenza may reduce the severity of the virus and hospital admissions in older adults, a study has found.
Researchers in Spain looked at the effect of repeated influenza vaccinations in the current and three previous seasons in people aged 65 years and older admitted to 20 Spanish hospitals in 2013/14 and 2014/15.
They found that repeated influenza vaccination was twice as effective in preventing severe influenza in people admitted to hospital for the virus, compared with nonsevere cases.
This effect was consistent regardless of flu season, virus subtypes or age of patient, researchers said.
"Repeated vaccination for influenza was highly effective in preventing severe and fatal infection caused by influenza in older adults," said Itziar Casado from Instituto de Salud Publica de Navarra in Spain.

The study published in the Canadian Medical Association Journal adds to findings from previous research that shows influenza vaccination reduces severity of the illness.
"Because severe cases of influenza may be prevented by two mechanisms, the effectiveness of vaccination against severe influenza may be greater than that for mild cases, and the benefit of influenza vaccination may be greater than that estimated in previous studies, researchers said.
"The prevention of severe and fatal infection caused by influenza was observed mainly in patients who were vaccinated in both the current and previous seasons, which reinforces the recommendation of annual vaccination for influenza in older adults," they said.