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ATLANTA -- After a 2-year absence, FluMist is back on the 2018-2019 influenza vaccine schedule, following a vote from the CDC Advisory Committee on Immunization Practices (ACIP) here. The panel also gave a unanimous endorsement to the Heplisav-B vaccine against hepatitis B virus.
ACIP members voted 12-2 to include the live attenuated influenza vaccine (LAIV) as "an option for influenza vaccination for persons for whom it is appropriate" in the 2018-2019 influenza season. An additional motion to give a preferential recommendation to the inactivated influenza vaccine (IIV) and recombinant influenza vaccine (RIV) over LAIV was voted down 3-11.
The vaccine was also added back to the Vaccines for Children (VFC) program in a 14-0 vote.
What changed their minds? CDC research from prior studies of live attenuated influenza vaccine showed that effectiveness of LAIV was 45% against influenza A and B, with 25% protection against influenza A (H1N1)pdm09 compared with unvaccinated children. CDC researchers also found that while inactivated influenza vaccine was "better" in all age groups against influenza A(H1N1)pdm09, compared with LAIV, there was no statistically significant difference in protection between the two vaccines for influenza A (H3N2) and influenza B viruses.
Raburn Mallory, MD, of MedImmune/AstraZeneca in Gaithersburg, Maryland, went through how the company corrected prior errors, specifically by choosing a new A/Slovenia strain for the LAIV4 vaccine, along with changes to the assays used in strain selection.
But there is no vaccine efficacy data on this new formulation of LAIV, said Lisa Grohskopf, MD, of the CDC in Atlanta, adding that effectiveness is "likely to remain unknown until the next H1N1-predominant season." However, she pointed out that the decision to recommend influenza vaccines "is not generally based upon effectiveness comparisons to other products."
The debate among the committee members centered around giving FluMist another shot. One of the "no" votes came from Henry Bernstein, DO, of Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York, who compared the vaccine to having "two strikes" in baseball, and said he didn't want to see a third strike during the coming flu season.
David Stephens, MD, of Emory University School of Medicine in Atlanta was the other "no" vote, saying "I'm really concerned about what message this [approval] sends."
The American Academy of Pediatrics (AAP) expressed some of the strongest objections. Liaison member David Kimberlin, MD, of the University of Alabama Birmingham, pointed out that the CDC meta-analysis was "too blended" to pull out strong consideration that LAIV has the kind of effectiveness they are hoping for. Also, the shedding data presented by the manufacturer does not correlate with effectiveness, he said.
"If we have an H1N1 year, and this vaccine has been recommended for use again and it doesn't work, that's a sobering sentence for me," said Kimberlin, who is also the AAP Red Book liaison to the CDC.
But committee member Edward Belongia, MD, of the Center for Clinical Epidemiology & Population Health in Marshfield, Wisconsin, pointed out that until the advent of the Flu VE network, recommendations for vaccines were based on immunogenicity.
"Given what we know, this is a reasonable approach. We always have to make the decision based on the best science available at the time, and I do think the manufacturer has made a good faith effort to understand the root causes of what was going on," he said.
The committee also declined to give a preferential recommendation to inactivated influenza vaccine or recombinant influenza vaccine over LAIV, voting down the motion proposed by Grace Lee, MD, of Stanford University School of Medicine in Stanford, California. They cited "uncertainty" and variability of the vaccine as the main reasons.
"We need to give people as many options to be vaccinated, because being vaccinated is better than not being vaccinated," said Laura Riley, MD, of Massachusetts General Hospital in Boston. A preferential recommendation is to "take the next step for which I'm not sure the data is all that compelling," she added.
Sharon Frey, MD, of the Saint Louis University School of Medicine in Missouri stated, "If [we] didn't want people to use LAIV, we should've voted against it."
In addition to Lee, the two other "yes" votes to preferentially recommend other influenza vaccines over LAIV were Stephens and Cynthia Pellegrini, of the March of Dimes. Prior to the vote, Pellegrini commented that "from a messaging point of view, this would communicate that we're cautiously wading back in with LAIV, but we're not willing to give it our full-throated approval."
Hepatitis B Vaccine
Earlier in the day, the committee also voted 14-0 for a non-preferential recommendation for the two-dose Heplisav-B vaccine as "a hepatitis B vaccine that may be used to vaccinate all people [ages ≥18 years] against infection caused by all known subtypes of HBV." The vaccine was approved by the FDA in 2017.
Data presented by the CDC indicated that this type of recommendation for the vaccine would likely improve hepatitis B vaccine series completion, provide earlier protection, and potentially "improved immunogenicity" among those with a typically poor vaccine response.
The recommended dosing schedule for Heplisav-B is two doses in one month.
ACIP members raised previous concerns about the occurrence of cardiovascular events, including acute myocardial infarction, which is likely to be addressed in post-marketing studies.
The committee also heard data about potential changes to hepatitis A post-exposure prophylaxis in certain populations (whether a vaccine should be given over or in addition to immune globulin), but deferred a vote on the issue until the June ACIP meeting.
As always, ACIP recommendations are not final until they have been published in the Morbidity and Mortality Weekly Report.