Full influenza vaccination among children cuts hospitalization in half: study

Fully vaccinating children reduces the risk of hospitalization associated with influenza by 54 percent, according to a study jointly conducted by the University of Michigan (UM), the Clalit Research Institute, and Ben-Gurion University in Israel.

The study, posted on UM's website on Wednesday, used data from Clalit Health Services, the largest health fund in Israel, to review the vaccination data of 3,746 hospitalizations of children six months to eight years old at six hospitals in Israel. They were tested for influenza over three winter seasons of 2015-2016, 2016-2017 and 2017-2018.

The findings reveal that the flu vaccine reduced hospitalizations associated with the flu by 54 percent, and that giving two vaccine doses to children up to age eight who have never been vaccinated or only received one dose previously is more effective than administering one dose.

"Young children are at high risk of hospitalization due to influenza complications," said study co-author Mark Katz, a senior researcher at the Clalit Research Institute, the research arm of Clalit Health Services.

The findings support health organizations' recommendations, including the Israel Ministry of Health to vaccinate children against influenza every year, preferably before the onset of winter or early childhood. Children under five are defined as having a high risk of influenza complications.

Children vaccinated are much better protected from influenza than those who only receive one vaccine, said Hannah Segaloff, a research fellow at the UM School of Public Health and lead author of the study.

"This study mirrors a previous study we conducted at Clalit Institute where we found that flu vaccine reduces 40-percent risk of hospitalizations in pregnant women," said Ran Balicer, director of the Clalit Research Institute and professor at the BGU School of Public Health.

"It reaffirms that vaccination is the most effective way to prevent both the flu and hospitalization. We hope parents will be aware of these facts and make an informed decision about the importance of vaccinating their children."

The researchers hope that this study and additional research will increase vaccination rates among the general public and, especially, children.