Q: The CDC’s ACIP encourages the completion of influenza vaccinations by the end of October each year. What are some related tips for practitioners? 

I would start by stressing the need to administer 2 doses in the same season for first-time vaccinations in children aged 8 years and younger. Many pediatricians do not appreciate how important that is, likely because they have not seen the serologic data. The intent of that first dose is not to protect the child, but rather to prime the child’s immune system. Consequently, the second dose is extremely important. Standing orders for vaccination are also important and have been shown to be an effective strategy, but many pediatricians have been hesitant to embrace them, perhaps because of concerns over acute illness and other complications. I would also recommend a consistent, text- phone-, or email-based reminder/recall strategy with respect to influenza vaccination, especially for young children who require 2 doses. This is an easy strategy to employ with just the touch of a button on today’s electronic medical record (EMR) systems. These EMRs should also be connected to every state’s immunization registry or information system. Leveraging community resources, such as pharmacies and school-based immunization programs, to ensure immunization also can help physicians to overcome the challenges of immunizing every child in the United States with a new vaccine in just a few months every fall. Finally, a wide array of different vaccine types provides physicians with choices. The CDC’s ACIP once again included the live attenuated influenza vaccine (LAIV) among the recommended options for 2019-2020 influenza vaccination, and the American Academy of Pediatrics (AAP) was similar in its recommendations, not expressing a preference for any single influenza vaccine among the age-appropriate, available options. Almost all vaccines for children, moreover, are now quadrivalent, which is an improvement over previous years.

For the 2019-2020 flu season, the CDC and the ACIP recommend vaccination for everyone aged 6 months and older with any licensed, age-appropriate influenza vaccine, in accordance with individual vaccine labels. The various formulations and doses of the inactivated influenza vaccine (IIV), quadrivalent recombinant influenza vaccine (RIV4), or quadrivalent LAIV (LAIV4) were included. For the 2019-2020 season, all IIVs for children in the United States were quadrivalent vaccines. Constituents for US trivalent influenza vaccines in 2019-2020 were hemagglutinin (HA) derived from an A/Brisbane/02/2018 (H1N1)pdm09–like virus, an A/Kansas/14/2017 (H3N2)–like virus, and a B/Colorado/06/2017–like virus (Victoria lineage). Quadrivalent influenza vaccines contained HA derived from these 3 viruses plus an additional influenza B vaccine virus, a B/Phuket/3073/2013–like virus (Yamagata lineage).

While specific vaccines may be preferable for an individual, both the ACIP and the AAP express no general preference as to which types of vaccine (ie, trivalent vs quadrivalent, injectable vs intranasal) should be used for persons for whom more than appropriate product is available. The concept of “no preference” highlights that it is more important that a child be vaccinated with an age-appropriate, licensed vaccine than to forgo vaccination altogether, owing to lack of availability of a specific, preferred product. The reformulated LAIV4 was recommended in the 2018-2019 ACIP guidance, based, in part, on data that were suggestive of the more robust vaccine efficacy seen in the past with this influenza vaccine. LAIV4 was once again included in the 2019-2020 ACIP recommendations, and the AAP guidance was harmonized with that of the ACIP, based on a variety of data points and considerations.

It is important for providers to start administering the influenza vaccine as soon as they have it available in their clinic, in accordance with current CDC recommendations. The influenza vaccine is usually available at the end of August or in early September every year. We have seen influenza activity begin as early as September or October in the United States. Influenza vaccine could be provided as soon as children return to school from summer break to ensure more opportunities for vaccination visits. Based on serum correlates of immunity observed with IIV, it takes about 2 weeks to have sufficient levels of protective antibodies, and young children, especially, need more time to become fully protected because they might need 2 doses of the vaccine. Yet, according to the latest CDC national coverage estimates, vaccine coverage rates in the pediatric population are still suboptimal.

The CDC recommends that influenza vaccination occur by the end of October, although getting vaccinated later can still be beneficial. Getting the influenza vaccine at the same time as being exposed to the virus may not provide enough time for the vaccine to prevent infection. Therefore, the influenza vaccine should be as accessible as possible. Working parents, in particular, face significant challenges in finding the time for themselves and their children to receive the influenza vaccine, so offering vaccinations early in the season and providing opportunities for walk-in vaccination visits, including after hours and on weekends, are extremely helpful.