Influenza Vaccine

Flu 2018-2019: Available Vaccines and Lessons Learned from Last Year

The 2017-2018 influenza season was quite severe, resulting in a reported 183 deaths among children alone.1 Influenza activity soared to levels reminiscent of the 2009 H1N1 pandemic. However, this time, influenza A(H3N2) emerged as the dominant strain.2

Although 67% effective against A(H1N1)pdm09 viruses, last season’s vaccine was only 25% effective against A(H3N2) and 36% effective against influenza A and B viruses overall, raising concern and likely fueling vaccine hesitancy across the country.3

Despite the limited effectiveness of last year’s vaccine, it remains highly important for patients—especially children—to be vaccinated against the virus each year, said board-certified pediatrician Jesse Hackell, MD, FAAP.

Although it is not possible to predict the severity of an upcoming influenza season or the effectiveness of available vaccines, focusing on prevention and educating patients and parents is still key.

In a Q&A with Consultant360, Dr Hackell, who serves as vice president and COO of Pomona Pediatrics, a division of Boston Children’s Health Physicians, shared his insights on last year’s influenza season.

He also discussed this year’s vaccine options and how pediatricians can prepare for the upcoming season.

Consultant360: Last year’s influenza season was one of high severity. What would you say are the most important lessons we learned from last year’s influenza season, especially with respect to pediatric influenza?

Jesse Hackell: The major lesson learned from last season's severe influenza season is that it is impossible to predict the coming season's severity in advance, and that prevention is far better than attempting to treat disease once it occurs.

Since we can never be sure how severe the upcoming season will be, it is prudent to encourage parents to be prepared and have their children vaccinated early and prior to the expected increase in influenza disease.

C360: What are some key points that pediatricians should know about vaccine options for the 2018-2019 influenza season?

JH: For the 2018-2019 season, all influenza vaccines contain the same strains of influenza virus. The trivalent vaccine contains antigens from two strains of influenza A and one strain of influenza B; and the quadrivalent vaccine adds antigens from a second influenza B strain. Both are available as single-dose in preservative-free and multi-dose vials (which do contain preservatives).

A live attenuated vaccine, administered by nasal spray, is again available this season following its absence for the past 2 seasons. 

C360: What should pediatricians know about the nasal spray vaccine, especially now that this option has been recommended again by the CDC for the first time in a couple of years?

 JH: FluMist (quadrivalent live attenuated influenza vaccine [LAIV4]) is available again this year. The CDC recommends the administration of any available approved vaccine, either the live attenuated nasal spray or the inactivated, injectable one, without expressing a preference for any particular choice.4

The American Academy of Pediatrics (AAP) recommendation is slightly different, however, recommending the inactivated vaccine as the "primary choice for influenza vaccination in children because the effectiveness of a live attenuated influenza vaccine against influenza A(H1N1) was inferior during past influenza seasons and is unknown for this upcoming season."5

The AAP goes on to state that the live attenuated vaccine may be given to children who would refuse the injectable vaccine and remain unprotected, if the LAIV4 is otherwise appropriate for them.5

C360: The CDC has said that last year’s vaccine was shown to have low effectiveness against certain strains of influenza, including last year’s dominant strain, A(H3N2). How can pediatricians reassure parents that having their children vaccinated against influenza this year is still necessary?

 JH: Because of the way that the influenza vaccine is developed, and because of the need to include different strains of virus each year, the choice of virus strains may sometimes not be a good match for the strains which eventually circulate in the community. For that reason and other reasons, vaccine efficacy can vary from one year to the next.

Nevertheless, the vaccine is the best option we have to offer any degree of protection, even if that protection is imperfect, and any benefit is preferable to none.

Pediatricians can reassure parents that the vaccine is also safe and has limited side effects, which tend to be minor, whereas the risk of developing influenza remains significant, with the potential for severe complications. When weighing these options, even a less than ideally effective vaccine is preferable to no vaccine in order to provide at least some reduction of risk.

Jesse Hackell, MD, FAAP, is a board-certified pediatrician based in Pomona, NY. He is the Vice President and COO of Pomona Pediatrics, a division of Boston Children’s Health Physicians.

—Christina Vogt

References:

  1. Summary of the 2017-2018 influenza season. Centers for Disease Control and Prevention. Page last updated October 11, 2018. https://www.cdc.gov/flu/about/season/flu-season-2017-2018.htm. Accessed on October 27, 2018.
  2. CDC update on widespread flu activity. Centers for Disease Control and Prevention. February 9, 2018. https://www.cdc.gov/media/releases/2018/t0209-flu-update-activity.html. Accessed on February 11, 2018.
  3. Flannery B, Chung JR, Belongia EA, et al. Interim estimates of 2017-18 seasonal influenza vaccine effectiveness- United States, February 2018. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep. 2018;67:180-185. http://dx.doi.org/10.15585/mmwr.mm6706a2.
  4. Grohskopf LA, Sokolow LZ, Broder KR, et al. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 influenza season. Recommendations and Reports. 67(3);1-20. http://dx.doi.org/10.15585/mmwr.rr6703a1.
  5. Committee on Infectious Diseases. Recommendations for prevention and control of influenza in children, 2018-2019. Pediatrics. 2018;142(4). doi:10.1542/peds.2018-2367.