Flu: What Docs Are Asking

Answers to physicians’ flu-related questions

The Immunization Action Coalition, which works with the CDC to educate health care professionals about vaccine recommendations in the United States, posts questions and answers from physicians and other health care providers. We present some of their key concerns below. For more information, please visit www.immunize.org.

If quadrivalent vaccine has one additional strain, why isn’t it preferred over trivalent vaccines?

Traditionally experts have to choose between the two very different B viruses to include with the two A viruses based on which type of B virus is expected to predominate. This can be difficult to predict. The quadrivalent vaccine for 2013–14 included both B viruses. However, while quadrivalent vaccines may eventually replace trivalent vaccines, only a limited quantity of quadrivalent vaccine is anticipated to be available. Consequently, ACIP does not express a preference for use of one type of influenza vaccine over another type for persons for whom more than one type of vaccine is indicated and available.

Which influenza vaccines can we give to children?

Among the injectable inactivated influenza vaccines (IIV), only Fluzone (Sanofi) is approved by the FDA for use in children ages six through 35 months. However, there are several injectable influenza vaccines that can be given to children age three or older.

The nasal spray live attenuated influenza vaccine (LAIV, FluMist, MedImmune) is approved for healthy children age two years and older. When immediately available, LAIV is preferred for use in healthy children ages two through eight who do not have a contraindication or precaution to LAIV. ACIP states this preference because two studies have shown LAIV to be more effective than IIV in preventing influenza in this age group. However, both LAIV and IIV are safe and effective in this age group. If LAIV is not immediately available, IIV should be used. Vaccination should not be delayed in order to procure LAIV.

The pneumococcal conjugate vaccine (PCV13) package insert says that in adults, antibody responses to Prevnar 13 (Pfizer) were diminished when given with inactivated influenza vaccine. Does this mean we should not give PCV13 and influenza vaccine at the same visit?

No. The available data have been interpreted that any changes in antibody response to either vaccines’ components were clinically insignificant. If PCV13 and influenza vaccine are both indicated and recommended they should be administered at the same visit.

The Vaccine Information Statement for inactivated influenza vaccine states that you should not get the vaccine if you are severely allergic to antibiotics. Which antibiotics are they?

The antibiotics, of which there are trace amounts in some influenza vaccines, are neomycin, gentamicin, and polymyxin B. You should check each product’s package insert information to see which, if any, antibiotics are listed.

How late in the season can I vaccinate patients?

Providers are encouraged to continue vaccinating patients throughout the influenza season, into the spring months. Because influenza occurs in many areas of the world during April through September, vaccine should be given to travelers who missed vaccination in the preceding fall and winter. Another late season use of vaccine is for children younger than age nine who needed two doses of vaccine but failed to get their second dose. For each of these situations, vaccine can be given through the month of June since most injectable influenza vaccine has a June 30 expiration date.