Repeated Flu Shots Were 2x as Effective in Preventing Severe Influenza

A new study looked into an old question… do annual influenza vaccinations lead to better health outcomes?

Seasonal influenza has a large effect on admissions to hospitals and deaths among older adults.

Influenza vaccination is effective in preventing visits to primary health care and hospital admissions for laboratory-confirmed influenza, but there is little research available on the effectiveness of influenza vaccinations on reducing the severity of the disease and fatal laboratory-confirmed influenza cases.

In this case-control study in 20 hospitals in Spain during the 2013/14 and 2014/15 influenza seasons, patients 65 years and older with laboratory-confirmed severe and nonsevere influenza who were hospitalized for longer than 24 hours were included in the case study.  

A trivalent inactivated influenza vaccine was recommended and offered free of charge to all people aged 65 years and older.

The results of the study compared patients unvaccinated in the last 4 seasons, to those who had received the influenza vaccine the current year and at least one previous season.  The adjusted effectiveness of the influenza vaccination in the current and any previous season resulted in:

• 31% in preventing hospitalizations for nonsevere influenza,
• 74% for ICU admissions
• 70% in preventing death.

However, vaccination only in the current season showed no reduced odds of severe disease and increased deaths.

These researchers conclude that repeated influenza vaccination was 2x as effective in preventing severe influenza compared with nonsevere influenza in hospitalized older patients, reinforcing recommendations for annual revaccination.

In the USA, the 2017-2018 flu vaccination effectiveness (VE) was reported to be just 36 percent effective.

Flu vaccines are still available at most pharmacies offering several FDA approved flu vaccines.

The CDC Vaccine Price List provides the private sector prices for general information.

Flu vaccine discounts can be found here.

Vaccines, like any medicine, can have side effects, says the CDC. You are encouraged to report negative side effects of vaccines to the FDA or CDC.