Flu vaccine reduces risk of hospitalisation

By Dr Jodie Abramovitch

Professor Allen Cheng (left) and
Associate Professor Tom Kotsimbos (right)

Vaccination against influenza infection is recommended in high risk groups including the elderly, pregnant women and those with chronic illnesses. The flu vaccine is primarily aimed at reducing the severe health consequences of infection such as hospitalisation and death. However, most previous studies on the influenza vaccine were performed in healthy adults and have looked at protection against mild influenza infection rather than severe complications.

As part of the Influenza Complications Alert Network (FluCAN), 17 sentinel hospitals, including the Alfred Hospital, report cases of influenza infections requiring hospitalisation. This data was designed to be used to assess burden of disease associated with flu and to estimate the effectiveness of the flu vaccine in preventing hospitalisation due to influenza. The study involved Monash researchers Professor Allen Cheng from the Department of Epidemiology and Preventive Medicine (DEPM) and Associate Professor Tom Kotsimbos from the Department of Allergy, Immunology and Respiratory Medicine (AIRMed).

During the 2014 influenza season, between April and November, 1692 adults were confirmed to have an influenza infection at the participating sentinel hospitals. The vaccination status of patients with flu was compared to patients admitted with non-flu related respiratory infections. In 2399 patients where vaccination status was known, half of those with confirmed flu had received their flu vaccination and two thirds of flu-negative patients had been vaccinated. As such, the flu vaccine was estimated to reduce hospitalisation by 51% during the 2014 flu season.

This study concluded that the flu vaccine was moderately protective in reducing hospitalisations in patients with confirmed flu infections.  

Reference: Cheng AC, Kotsimbos T, Kelly PM; FluCAN Investigators. Influenza vaccine effectiveness against hospitalisation with influenza in adults in Australia in 2014. Vaccine. 2015 Dec: 33;7352-6

doi: 10.1016/j.vaccine.2015.10.016.