A variety of new influenza vaccination alternatives on tap for the coming flu season

January 12th, 2015

An unprecedented variety of influenza vaccines will be available for the 2013-2014 flu season, including one designed to be used safely by people with egg allergies – a condition that has long made the traditional egg-based shot strictly verboten.

A recombinant flu vaccine (Flublok by Protein Sciences Corp.) that is not produced with eggs will be available this fall for people between the ages of 18 and 49. Flublok, also known as RIV3, is an alternative for people with any type of egg allergy. Produced using insect cells and recombinant DNA technology, it is provided in single-dose vials and has a shelf life of only 16 weeks after manufacture. The Centers for Disease Control and Prevention advises health care providers to check the expiration date before using the product.

Other varieties of flu vaccination shots/mists are slated as well. In June, the Advisory Committee on Immunization Practices (ACIP), an expert panel that advises CDC, approved the use of quadrivalent vaccines, which protect against two influenza A strains and two influenza B strains. (The trivalent vaccines target only one B strain.) Fluzone by Sanofi Pasteur is available as an intradermal vaccine, with a tiny needle, and in a high-dose version, with four times the usual amount of antigen, geared toward people 65 years and older. The high-dose version produces a better immune response in older adults, but it’s not clear yet whether that equates to greater protection, the CDC says. The quadrivalent vaccine also is available as a nasal spray — FluMist by MedImmune, which is a live attenuated vaccine that is approved for people ages 2 to 49.

Despite the range of products, vaccine effectiveness remains a concern. The 2012-2013 flu season began earlier than usual and peaked in late December. CDC reported 152 influenza-related pediatric deaths, more than any year since 1997, except for the 2009 H1N1 pandemic.

But the main tool for preventing influenza transmission was only 52% effective, reported Mark Thompson, PhD, an epidemiologist in the CDC influenza division. It was especially problematic against influenza A (H3N2), with an effectiveness of only 19% for people 65 and older and 40% for people 18 to 49.

However, the reduced the risk of outpatient medical visits due to influenza A (H3N2) by 44% for everyone but children ages 9 to 17 and people 65 and older, and it reduced medical visits due to influenza B by 62% for people of all ages. CDC also reported that it reduced the risk of hospitalization.

“The vaccine may have reduced the likelihood of more severe illness,” Thompson said.

--Michelle Marill, Hospital Employee Health