Vaccination Recommendations for the 2013-2014 Influenza Season

Joseph Bresee, MD

September 27, 2013

Changes to This Season's Vaccine Recommendations

Hello. I am Dr. Joe Bresee from CDC's Influenza Division. I am pleased to speak with you today as part of the CDC Expert Commentary Series.

Today I will discuss vaccination recommendations for the 2013-2014 influenza season. Of greatest importance, CDC continues to recommend that everyone 6 months and older receive a yearly flu vaccine, with rare exceptions. But there are some changes to this season's recommendations, which is what I will be focusing on in this commentary. First I will discuss the vaccine options available in the United States. This season, some quadrivalent vaccines will be available, along with the trivalent vaccine, which has been available for decades. The trivalent flu vaccine contains 3 antigens: an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. The quadrivalent vaccine contains these 3 and a second B antigen. All nasal spray vaccines this season will be quadrivalent. Inactivated flu vaccines, which are administered as intramuscular and intradermal injections, will be available in both trivalent and quadrivalent formulations. Most of the flu shots available this season will be trivalent vaccines. There is no need to delay vaccination if the quadrivalent vaccine is not available, because both types of vaccine offer important protection from flu. Trivalent flu vaccines are available as:

• A standard-dose injection approved for use in people ages 6 months and older, including those with high-risk medical conditions and pregnant women;

• A high-dose injection approved for use in people 65 years and older;

• An intradermal injection that is approved for use in people 18 through 64 years of age and uses a much smaller needle than the regular flu shot;

• A standard-dose, cell-based flu shot for use in people 18 years and older;

• A recombinant, egg-free shot approved for use in people between 18 and 49 years; and

• A nasal spray (or intranasal) vaccine, approved for healthy people ages 2-49 who do not have an underlying medical condition, such as asthma or diabetes, that predisposes them to serious influenza complications.

For a complete list of available vaccines along with trade names, manufacturers, presentations, mercury content, age indications, and routes, see this list of seasonal vaccines. This year, vaccine shipments began in late July and will continue until all vaccine is distributed. Manufacturers have projected that they will produce between 135 million and 139 million doses of influenza vaccine for use in the United States this flu season.

There is no preferential recommendation for any type or brand of licensed influenza vaccine over another. Different formulations are available from various manufacturers, so clinicians should refer to the package inserts for the recommended age groups, contraindications, and precautions for each vaccine.

Flu Vaccines for Young Children

Now I will briefly talk about dose recommendations for young children. The following children will require 2 doses of influenza vaccine, administered at least 4 weeks apart, for full protection:

• Children aged 6 months to 8 years who have never been vaccinated against influenza or for whom vaccination history is unknown; and

• Children who have not previously received at least 2 doses of seasonal vaccine and at least 1 dose of pandemic 2009(H1N1)-containing vaccine;

• Children who have received at least 2 doses of seasonal vaccine and at least 1 dose of pandemic 2009(H1N1) vaccine previously will need only 1 dose this season.

The Advisory Committee on Immunization Practices has developed an algorithm that might be helpful in determining the number of doses needed.

Finally, I would like to say a word about egg allergies. Although the nasal spray vaccine should not be used in patients with allergy to eggs, other safe flu vaccine options are available.

People with mild allergies to egg -- specifically, people who experience only hives in response to egg exposure -- may receive either recombinant or inactivated influenza vaccine. The recombinant vaccine, FluBlok®, is egg-free and is approved for people 18-49 years old who have no other contraindications. Inactivated (egg- or cell-culture based) vaccine may also be used, as long as the vaccine is administered by a healthcare provider who is familiar with the potential manifestations of egg allergies, and the recipient can be observed by a healthcare professional for at least 30 minutes after receiving each dose.

Egg-allergic people who have experienced any symptoms other than hives after egg exposure also may receive recombinant vaccine if they are between the ages of 18 and 49 and have no other contraindications. If recombinant vaccine is not available or if the recipient is not 18 through 49 years old, referral to an allergy expert should be obtained prior to vaccination.

In closing, your recommendation to your patients that they get vaccinated is more effective in increasing acceptance of vaccination than any other influencing factor. The CDC Influenza Free Resources includes brochures, posters, fact sheets, customizable reminder cards, and social media tools that are all designed to help you educate and reach your patients with a reminder to get vaccinated.