Nasal Flu Vaccine Reported Effective in UK Children

Why is the nasal flu vaccine working in the UK, but not in the USA?

There are currently two types of influenza vaccines, inactivated or recombinant vaccines, and live attenuated vaccines (LAIV), commonly known as the nasal spray.

The proposed advantages of the LAIV were that they had superior efficacy compared to inactivated vaccines in young children.

According to new information from the UK, the live-attenuated influenza vaccine had a 65.8% vaccine effectiveness (VE) rate during the 2016-17 flu season in UK children ages 2 to 17.

The data further support the use in UK children of LAIV4, or four-strain LAIV, which was the version used in the United Kingdom this past season, despite a lack of efficacy demonstrated in studies among US children.

Today's report, written by Public Health England (PHE) and other UK experts, also noted that the inactivated influenza vaccine (flu shot) had a statistically not significant VE of 43.2% in the same age-group.

In adults ages 18 to 64, VE was 40.6%, and the vaccine was not effective for adults 65+ in age.

Additionally, the UK has found evidence of LAIV4 effectiveness during the 2015/16 flu season of 58%.

"Although the seasonal influenza vaccine was effective against influenza A (H3N2) infection in younger adults, there was no evidence of significant effectiveness of inactivated vaccine in people aged 65 or older," the authors wrote.

"On the contrary, in children there was good effectiveness for LAIV4 against influenza A (H3N2) and a suggestion of effectiveness against influenza B, for which there were only limited detections."

The 2016-17 flu season was dominated in Europe by influenza A strain H3N2.

Jenny Harries, Deputy Medical Director for Public Health England said, “It is good news that last winter children were particularly well protected against flu with the vaccine nasal spray.”

“We know children can spread flu more than others and if we can keep them well it means that the infection is less likely to pass to those who are at high risk. We also saw the risk of flu fall by over 40% in vaccinated adults under 65 allowing more people to stay well last winter,” said Dr. Harris. 

This data from the UK’s NHS is in contrast to the Centers of Disease Control and Prevention (CDC), where reduced LAIV vaccine effectiveness has been reported.

The CDC  recommended to suspend use of LAIV in children during 2016/17. 

There remains an important, unanswered question that would explain the reduced LAIV effectiveness in the USA.

Most pharmacies in the USA offer several FDA approved flu vaccines.

The flu shot cost varies depending upon your insurance and which state you live.

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

Flu vaccine discounts can be found here.

For further information on influenza, its burden on human health and vaccine development, please visit the CDC website.