In a unanimous decision, the CDC’s Advisory Committee on Immunization Practices supported the recommendation that all people aged 6 months and older be vaccinated annually against influenza; however, the committee will no longer recommend a preference for nasal spray vaccine in healthy children aged 2 to 8 years.
Other data presented to the ACIP on Feb. 26 demonstrated that the 2014-2015 influenza vaccine was not effective against the predominant H3N2 viruses. The mid-point vaccine effectiveness (VE) estimate for inactivated influenza vaccine (IIV) was 15% (95% CI, –20 to 40) compared with –23% (95% CI, –90 to 21) for the live-attenuated influenza vaccine (LAIV), according to interim data from the U.S. Flu VE Network.
“Low interim VE estimates are consistent with the predominance of antigenically drifted H3N2 viruses,” Brendan Flannery, PhD, an epidemiologist with the CDC, said. “H3N2 accounted for 95% of all influenza positive cases at U.S. Flu VE Network sites, and more than 80% of genetically characterized H3N2 cases were substantially drifted from the H3N2 virus. In analyses by viral genetic group, we observed low or no vaccine effectiveness against drifted H3N2 viruses.”
Other data showed that the poor performance in 2010-2011 and 2013-2014 of LAIV against A/California H1N1 was linked to a mutation that rendered the strain vulnerable to heat. Going forward, the vaccine’s manufacturer, MedImmune, will replace the mutated influenza A/California H1N1 strain with an antigenically similar strain with a more stable hemagglutinin.
Meningococcal B vaccine for at-risk people
In another vote, the ACIP unanimously recommended serogroup B meningococcal vaccinations in people aged 10 years and older who are at high risk for the disease: people with persistent complement component deficiencies, people with anatomic or functional asplenia, microbiologists who are regularly exposed to the Neisseria meningitidis isolates and people at risk due to community disease outbreaks.
Two serogroup B vaccines are now available: the three-dose series Trumenba (Pfizer) was approved in October 2014; Bexsero (4cMenB, Novartis), a two-dose series, was approved in January.
The ACIP will discuss universal recommendations at its June meeting.
9vHPV added to routine vaccine list
The ACIP also voted to add the 9-valent human papillomavirus (9vHPV) vaccine (Gardasil, Merck) to the routine recommendations for the vaccination of boys and girls aged 11 and 12 years. Vaccinations can start as early as age 9.
In addition, they supported vaccination for females aged 13 to 26 years and for males aged 13 to 21 years who previously have not been vaccinated or who did not complete the three-dose series.
Furthermore, if physicians do not know or have available the vaccine used initially, they may use any available HPV vaccine to complete the dose series in females; for males, they may use HPV4 or HPV9.
Yellow fever vaccine
In other business, the ACIP unanimously agreed that one dose of yellow fever vaccine is adequate for most travelers. One booster dose is required for women who were pregnant when they received their initial dose of yellow fever vaccine and people who received a hematopoietic stem cell transplant after receiving a yellow fever vaccine and who are now sufficiently immunocompetent.
People who were HIV infected at the time of their yellow fever should get boosters every 10 years if their travel continues to put them at risk.
A booster dose should be considered for people who will travel to endemic or highly endemic areas whose last vaccine dose was at least 10 years ago.
Laboratory workers who routinely handle wild-type yellow fever virus should have yellow fever-specific neutralizing antibody titers measured at least every 10 years to determine if additional vaccine doses are necessary. – by Colleen Owens