Vaccine Recommendations for the 2016-2017 Flu Season

Editor's Note: Don't miss our other reports on the Center for Disease Control and Prevention's (CDC's) influenza vaccine recommendations for 2016-2017, including No LAIV (Nasal Spray) Flu Vaccine This Season and Flu Vaccine for People With Egg Allergies. In addition, please visit our Influenza Resource Center often for updates.

I am Lisa Grohskopf, from CDC's Influenza Division. I am happy to speak with you today as part of the CDC Expert Commentary Series on Medscape. Today I will be highlighting for you the most pertinent information related to 2016-2017 influenza vaccines and CDC's vaccination recommendations.

CDC recommends that everyone aged 6 months or older receive an influenza vaccine every year, by the end of October if possible. However, CDC continues to recommend that influenza vaccination efforts continue as long as influenza viruses are circulating in the community. Significant seasonal influenza virus activity can continue into May, so vaccination later in the season can still provide benefit during most seasons.

One big change for the 2016-2017 season is that only injectable influenza vaccines are recommended for use. Live attenuated influenza vaccine (also known as the nasal spray) is not recommended for use during 2016-2017 because of concerns about effectiveness.

Recommended 2016-2017 influenza vaccines include a number of inactivated injectable vaccines as well as recombinant influenza vaccine. Both trivalent and quadrivalent injectable vaccines will be available this season. Trivalent vaccines are designed to protect against three different influenza viruses. Quadrivalent influenza vaccines protect against the same three viruses plus an additional B virus from a different lineage of influenza B viruses. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate.

The 2016-2017 vaccine options are listed in the table of US influenza vaccines in Morbidity and Mortality Weekly Report^[1] and include the following:

Standard-dose trivalent injectable vaccines that are manufactured using virus grown in eggs will be available. This type of influenza vaccine has been around for decades. There are two standard-dose inactivated injectable trivalent influenza vaccines: Afluria® and Fluvirin®. These products are approved for different age groups. Most inactivated injectable influenza vaccines are administered intramuscularly with a needle. However, Afluria also can be given with a jet injector to persons 18 years through 64 years.
A high-dose injectable inactivated trivalent influenza vaccine called Fluzone® High-Dose will also be available. This vaccine, which was first approved in 2009, has four times the amount of antigen as regular-dose inactivated influenza vaccines. The additional antigen is intended to create a stronger immune response. This vaccine is approved for people aged 65 years and older, who often have a lower protective immune response after flu vaccination compared with younger people. Results from a clinical trial of more than 30,000 participants showed that adults aged 65 years and older who received the high-dose vaccine had 24% fewer influenza infections compared with those who received a standard-dose influenza vaccine.
Also available again this season is a recombinant trivalent influenza vaccine that is egg-free called Flublok®. This vaccine is approved for people aged 18 years old and older.
New this season is an inactivated trivalent influenza vaccine made using adjuvant, which is approved for people aged 65 years and older. Adjuvants are added to vaccines to create stronger immune response to vaccination and sometimes as part of a strategy to stretch the number of doses that can be produced. The vaccine is called Fluad™ and was licensed in November 2015. It contains MF59 adjuvant, an oil-in-water emulsion of squalene oil. Fluad is the first adjuvanted seasonal influenza vaccine marketed in the United States. In a Canadian observational study of 282 persons aged 65 years and older conducted during the 2011-2012 season, Fluad was 63% more effective than regular-dose unadjuvanted inactivated influenza vaccine.
Quadrivalent inactivated injectable influenza vaccines manufactured using virus grown in eggs will be available again this season. This is a standard-dose influenza vaccine, manufactured using production techniques that have been around for decades. There are four quadrivalent inactivated injectable influenza vaccines: Fluarix®, FluLaval®, Fluzone®, and Fluzone® Intradermal. These are approved for different age groups down to 6 months of age. Fluzone Intradermal is approved for intradermal administration in people 18 years through 64 years.
New this season is the availability of a quadrivalent standard-dose cell culture-based vaccine called Flucelvax®. Cell-based flu vaccines are made by growing viruses in animal cells instead of eggs. Flucelvax is approved for people aged 4 years and older. Cell-based influenza vaccines were first approved in the United States in 2012, but these vaccines were originally trivalent. This is the first season that cell-based quadrivalent influenza vaccine will be available.

Of note, the composition of this season's vaccines has been updated to better match more recently circulating influenza viruses. Specifically, all of the 2016-2017 vaccines are recommended to 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, which is a B/Victoria lineage B virus.

Quadrivalent vaccines also will include a B/Phuket/3073/2013-like virus, which is a B/Yamagata lineage virus.

Please visit the table of US influenza vaccines for 2016-2017 for more information on any particular vaccine.

I want to reiterate that the approved quadrivalent live attenuated influenza vaccine called FluMist® Quadrivalent is not recommended for use during 2016-2017. For the remaining licensed and recommended influenza vaccines, there is no preferential recommendation for one vaccine over another.

Another change in influenza vaccination recommendations relates to the guidance for the vaccination of egg-allergic patients. This topic is addressed in-depth in a separate commentary, Flu Vaccine for People With Egg Allergies, but, in summary, the recommendation has been updated such that people with egg allergies can receive any licensed, recommended, age-appropriate influenza vaccine and no longer have to be monitored for 30 minutes after receiving the vaccine. People who have severe egg allergies should be vaccinated in a medical setting and be supervised by a healthcare provider who is able to recognize and manage severe allergic conditions.

Some children younger than age 9 years will continue to require two doses of influenza vaccine. For 2016-2017, children aged 6 months through 8 years who have previously received two or more total doses of trivalent or quadrivalent influenza vaccine before July 1, 2016, only need one dose of 2016-2017 seasonal influenza vaccine. The two doses don't need to have been given during the same season or consecutive seasons.

Thank you for your attention. I will close by reminding you about the importance of your role in protecting the public against influenza. Studies have shown repeatedly that a healthcare provider's recommendation plays a critical role in a patient's decision to get a seasonal influenza vaccine. Please help protect as many people as possible against influenza during the 2016-2017 season.

Contact CDC-INFO at 1-800-CDC-INFO or CDCINFO@cdc.gov if you have any questions following today's update.

Web Resource

Seasonal Influenza – Health Professionals