CDC’s Advisory Committee on Immunization Practice (ACIP) addressed recommendations for the use of new vaccines such as the meningococcal B and the 9-valent human papilloma vaccine (HPV) vaccines at its February 26, 2015, meeting. Complete minutes of the meeting are published on the CDC National Immunization Program website.
ACIP voted on and approved use of the new meningococcal B vaccines (Bexsero—Novartis; Trumenba—Pfizer) for high-risk groups and will consider other uses at future meetings.
The meeting discussion was limited to the use of meningococcal B vaccine for high-risk patients only. High-risk patients for meningococcal B infection include persons with complement deficiencies, persons presently taking eculizumab (Soliris—Alexion), persons who are asplenic, microbiologists, and those exposed during outbreaks of disease. Special populations that were not considered for vaccination at this meeting include college students living in residence halls, travelers, and military recruits. While data are limited, the immunogenicity and safety of the available vaccines were not concerning. More studies are ongoing.
ACIP voted on and approved similar recommendations for the new 9-valent HPV vaccine (Gardasil 9—Merck) as the original 4-valent vaccine (Gardasil—Merck), with use recommended in young women aged 9–26 years and young men aged 9–21 years.
Numerous presentations have been made over the last year to ACIP about the new 9-valent HPV vaccine approved by FDA. The vaccine showed approximately 97% efficacy against the five new HPV types and a noninferior response to the original 4-valent vaccine. The adverse events were also similar. Cost-effectiveness models showed cost savings with a switch to the HPV9 vaccine for use in both sexes. Even though data are limited on the use of this vaccine in males, the ACIP workgroup proposed to follow recommendations similar to those for the 4-valent vaccine. There was no recommendation to revaccinate those who already received HPV4 vaccine. This will be discussed as more data are available.
ACIP voted and approved to continue to recommend that all people aged 6 months and older be vaccinated annually against influenza. In its 2015–16 recommendations, ACIP did not renew the 2014–15 preference for using the live-attenuated influenza vaccine (LAIV) instead of the inactivated influenza vaccinations (IIV) in healthy children aged 2–8 years because data suggested decreased effectiveness with LAIV compared with IIV against circulating strains.
The discussion was limited to the influenza vaccines and their effectiveness, with particular attention to LAIV (Flumist—MedImmune). The U.S. Flu Network follows overall vaccine effectiveness and reported on influenza strains collected from November 10, 2014, through January 30, 2015. Eighty-five percent of the H3N2 virus in circulation was drifted from the predicted strain. The relative vaccine effectiveness for all ages against all viruses (A and B) was 19%. When A(H3N2) strains were analyzed, the vaccine effectiveness for the drifted strain was 0%–15%, and the vaccine effectiveness for the vaccine-like strains was 49%.
When LAIV was analyzed separately, the adjusted vaccine effectiveness showed no effectiveness of LAIV against the drifted strain. Studies performed by MedImmune showed a vaccine effectiveness of 16% against the A(H3N2) compared with 33% for the IIV. The conclusion was that there was low effectiveness of IIV and even lower effectiveness of LAIV against the drifted strain A(H3N2). The committee will wait for final reports at the end of the season.
ACIP voted on and approved recommending a single dose of yellow fever vaccine (YF-Vax—Sanofi Pasteur) for international travel; however, additional doses are recommended for certain high-risk patients (i.e., pregnant women, patients with hematopoietic stem cell transplants, HIV patients, and laboratory workers). In addition, ACIP noted that a booster dose may be recommended for travelers who are in high-risk settings based upon season, location, activities, and duration of travel.
In April 2013, the World Health Organization recommended that a single dose of yellow fever vaccine is sufficient to confer lifelong protection and that a booster is not necessary. The change to the International Travel Regulations, which currently state that a traveler needs a yellow fever vaccine within the last 10 years, will take effect by June 2016.