CDC continues to recommend that everyone aged 6 months and older who does not have contraindications receive a routine annual influenza vaccination. Influenza vaccinations should be given by the end of October, if possible; however, administering the vaccine later in the season is also an option. CDC noted that vaccination efforts should be structured to ensure vaccination of as many persons as possible before the influenza activity in the community begins, but efforts should continue throughout the season as long as influenza viruses are circulating and unexpired vaccines are available. Pharmacists should maximize every encounter with patients to vaccinate them throughout the influenza season to avoid missed opportunities.
As previously reported by CDC, the live attenuated influenza vaccine (LAIV) should not be used during the 2016–17 season because low effectiveness was noted during earlier influenza seasons. Therefore, only the injectable inactivated influenza vaccine (IIV) and recombinant influenza vaccine (RIV) should be used. For the 2016–17 season, the content of the influenza vaccine has been modified to better match anticipated circulating viruses. These changes include an A/California/7/2009 (H1N1)pdm09-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (B/Victoria lineage) in trivalent vaccines, with the addition of a B virus, B/Phuket/3073/2013-like virus (B/Yamagata lineage), in the quadrivalent vaccines.
Two new influenza vaccines have been approved since last season—Fluad (Seqirus) and Flucelvax (Seqirus)—and are included in the updated recommendations. Fluad, an MF59-adjuvanted trivalent IIV, was approved by FDA in November 2015 for persons aged 65 years and older. It is the first adjuvanted influenza vaccine marketed in the United States and has demonstrated noninferiority for seroconversion rate differences and geometric mean titer ratios when compared with nonadjuvanted trivalent IIVs among older adults.
Flucelvax, a quadrivalent formulation, is a cell culture–based IIV approved by FDA in May 2016 for persons aged 4 years and older. This vaccine has also demonstrated comparable efficacy and safety with previously licensed competitors. CDC does not give any preference to these vaccines for the approved age groups and lists them as alternatives to other vaccine products already available for these patient populations.
Finally, a few of the recommendations for administering influenza vaccine in those with a history of egg allergy have been modified. Specifically, CDC removed the recommendation of observing patients with egg allergy for 30 minutes postvaccination for an allergic reaction. Instead, CDC noted that consideration can be given to observing patients for 15 minutes postvaccination to avoid the risk of injury if syncope should occur. In addition, CDC noted that for patients who have a history of a severe allergic reaction to eggs (e.g., angioedema, respiratory distress), the influenza vaccine should be administered in an inpatient or outpatient medical center under the close supervision of a medical provider who can manage these potential reactions.