ATLANTA -- The CDC's Advisory Committee on Immunization Practices (ACIP) voted to reaffirm their core recommendations for the 2018-2019 influenza season. The panel also unanimously approved recommendations for anthrax vaccination in a "mass event."
ACIP members voted 13-0, with one recusal, that live attenuated influenza vaccine (LAIV, sold as FluMist) can be back on the roster, reiterating the recommendation first approved in February.
Representatives from the American Academy of Pediatrics (AAP) continued to exercise caution regarding LAIV. James Campbell, MD, of the AAP Committee on Infectious Diseases, noted that the AAP voted to recommend inactivated influenza vaccine (IIV) as "first choice"; but for those who would otherwise not get vaccinated, LAIV could be offered if age-appropriate and not contraindicated.
Other recommendations for flu immunization included that all persons ages 6 months and older be vaccinated against influenza, as well as the composition of this year's trivalent and quadrivalent influenza vaccines.
Composition of this year's trivalent influenza vaccines include the following strains, previously selected by the World Health Organization and FDA:
- A/Michigan (H1N1 pdm09)
- A/Singapore (H3N2)
- B/Colorado
Quadrivalent vaccines will contain the above strains, plus B/Phuket (Yamagata lineage). As previously noted, the A/Singapore and B/Colorado strains are updated strains this year.
In addition, there will be a new product available -- Fluarix Quadrivalent (GlaxoSmithKline), which was licensed in January 2018 for children age ≥6 months.
The committee also heard a presentation on cell-cultured vaccines compared to egg-based quadrivalent vaccines for older adults age ≥65. The study concluded that both cell-cultured and high-dose vaccines were "marginally more effective" for hospital outcomes (cell-cultured vaccines were about 10% more effective and high-dose vaccines were about 8% more effective in this population).
Committee member Paul Hunter, MD, of the University of Wisconsin School of Medicine and Public Health, raised the issue about comparing effectiveness of vaccines "if they each vary from season to season," and committee members agreed that more data is needed.
Anthrax Vaccination Following a 'Mass Event'
The committee also voted 14-0 for three recommendations for anthrax vaccine as post-exposure prophylaxis in a mass vaccination campaign:
- Intramuscular route of administration may be used if the subcutaneous route of administration presents clinical, operational, or logistical challenges that may delay or prevent vaccination
- Should there be an inadequate supply of anthrax vaccine available for post-exposure prophylaxis, either two full doses or three half-doses of anthrax vaccine absorbed (AVA) may be used to expand vaccine coverage
- In immunocompetent individuals age 18-65, antimicrobials given in conjunction with vaccine may be discontinued at 42 days after the first vaccine dose or 2 weeks after the last vaccine dose, whichever comes later
Campbell said that the AAP recommends 60 days of antimicrobials for children, but the group also "agreed" that the other two recommendations could be applied to that population. William Bower, MD, of the CDC, who gave the presentation on the anthrax vaccine, said that human data on this vaccine was only developed from studies on "healthy adult volunteers" ages 18 to 65. But if such a "mass event" were to take place, "planned studies" would collect data on the vaccine in children and older adults, he added.
Naturally, the committee had questions on what constituted a "mass event." Bower said that it would be based on the "operational capacity of the jurisdiction where the event is happening." He added that these recommendations would be for an "emergency situation," where the exposed population exceeds the vaccine supply.
Committee members raised questions about whether to recommend one half-dose over the other, but ACIP chair Nana Bennett, MD, of the University of Rochester, cautioned against creating "permissive recommendations."
"We need to give the best guidance we can, but make it as unrestricted as we can. It's not really something we can make perfect recommendations for," she said.
Bower added, "Getting vaccine into people's arms whenever you can will save lives."
As always, ACIP recommendations are not final until they have been published in the Morbidity and Mortality Weekly Report.