Adjuvanted Influenza Vaccine Beneficial for Young Children

Adjuvanted influenza vaccine 55% more effective after the first dose than non-adjuvanted vaccines.

Influenza can threaten the health of young patients and poses a financial burden to the healthcare system. While the flu results in many deaths each year, a significant number of cases can be prevented with vaccination.

For the 2017/2018 influenza season, the CDC recommends that individuals aged over 6 months who do not have contraindications receive the seasonal vaccine to prevent serious illness. Vaccination is especially important among patients with weak immune systems, such as children and elderly adults.

Findings from a new phase 3 study suggest that an adjuvanted influenza vaccine (aQIV) that protects against 4 strains of influenza may be superior to non-adjuvanted quadrivalent vaccine, according to a press release.

Included in the study were 10,612 pediatric patients aged 6 months to less than 6 years who received 1 or 2 doses or aQIV or a non-adjuvanted vaccine. Endpoints included confirmed influenza and immunogenicity against influenza A and/or B.

The investigators found that vaccination with aQIV resulted in a better immune response in children than those treated with a similar vaccine. The aQIV also protected against a drifted strain that circulated during the 2014/2015 influenza season, according to the release.

The aQIV was found to provide clinical benefit over non-adjuvanted influenza vaccine in very young children less than 24 months to 6 years. The investigators found that aQIV was 31% more effective in this population. The authors also noted that aQIV had the largest relative increase in immunogenicity compared with older children, according to the release.

“One challenge to lowering pediatric hospitalization rates is that the effectiveness of currently licensed influenza vaccines is uncertain in young children, especially those under the age of 2,” said researcher Timo Vesikari, MD, PhD. “As a result, vaccines that are more effective in preventing influenza in this age group, like the MF59-adjuvanted quadrivalent influenza vaccine (aQIV), are desirable.”

The authors found that aQIV was 55% more effective in preventing influenza after the first dose of the vaccine compared with non-adjuvanted vaccination in vaccine-naïve children. These findings highlight the importance of the aQIV, as it can protect after 1 dose.

The overall safety profile of aQIV was similar to other vaccines, except there was a higher expected incidence of solicited adverse events with the experimental treatment, according to the authors.

“Influenza and its complications pose a serious public health threat to young children, especially those under 2 years of age,” Dr Vesikari said. “Because standard influenza vaccines are less efficient in producing a robust immune response in young children, improved vaccines are urgently needed. Our study demonstrated that aQIV represents an important new opportunity to introduce a potentially improved influenza vaccine option.”