RIV4 Flu Vaccine Successfully Protected Children Six Years and Older

Quadrivalent recombinant influenza vaccine found safe for children

The recombinant influenza vaccine is well established as effective in preventing the seasonal flu in adults over the age of 18 years.

But, does this flu vaccine work for younger people?

That was the question researchers answered in a new randomized controlled, clinical trial.

Seasonal influenza vaccines have transitioned recently to quadrivalent formulations containing antigens representing both influenza B lineages (Yamagata and Victoria) as well as the conventional influenza A subtypes H1N1 and H3N2.

The second influenza B lineage has been added to address the high frequency of circulation of both B lineages in a single season, and the common circulation of influenza B lineage mismatched with the vaccine strain.

Because children are especially susceptible to complications of influenza B, pharma companies initiated the development of the quadrivalent, recombinant influenza vaccine (RIV4) for children aged 6 to 17 years.

The participants in this study were randomly assigned to receive RIV4 (Flublok Quadrivalent, Protein Sciences Corporation) or IIV4 (Fluarix Quadrivalent, GSK).

This study reported the safety, reactogenicity, and immunogenicity of the RIV4 in pediatric subjects 6 to 17 years of age were comparable to those in the profile of the IIV4 in pediatric subjects ≥6 years of age.

Which means, despite low responses to influenza B lineages in both vaccines, both vaccines were well tolerated in both age groups, and long-term follow-up revealed no vaccine-related adverse events.

An earlier phase 1 clinical trial of trivalent, recombinant influenza vaccine (RIV3) in a healthy pediatric population aged 6 to 59 months revealed that RIV3 was safe and well tolerated but yielded inferior levels of hemagglutination inhibition (HAI) antibody titers compared with those induced by the trivalent inactivated influenza vaccine (IIV3).

The 2018 flu season was dominated by the Influenza A (H3N2) virus, a strain that is less receptive to current flu vaccines, says the Centers for Disease Control and Prevention (CDC).

The CDC reports the overall estimated vaccine effectiveness of the 2017–18 seasonal influenza vaccine for preventing medically attended, laboratory-confirmed influenza A virus infection was 36 percent.

The CDC's midseason Vaccine Effectiveness report against B viruses was 42 percent. The CDC says the number of influenza B cases have surpassed influenza A.

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.

FINANCIAL DISCLOSURE: Drs Dunkle, Izikson, and Cox are employees and shareholders of Protein Sciences Corporation, which is the manufacturer of Flublok Quadrivalent. Protein Sciences is wholly owned by Sanofi Pasteur. Drs Patriarca and Goldenthal are paid consultants to Protein Sciences Corporation and to numerous other vaccine manufacturers. Dr Treanor consults for and conducts clinical trials with multiple vaccine manufacturers.