Immunization Update and ACIP Highlights – February 2016

March 14, 2016

The Advisory Committee on Immunization Practices (ACIP) of the CDC met on February 24 to provide guidance on vaccines.​ Below are the key highlights


·         The 2016-2017 Influenza Vaccine Recommendations were approved, and most restrictions for giving any influenza vaccine to egg-allergic recipients were removed
·         The FDA approved the use of 9vHPV vaccine in males ages 16-26 years, and Merck will retire the 4vHPV vaccine in 2016
·         CDC has developed a set of goals to address the Zika virus including vaccine development
·         Evidence was presented supporting future recommendations regarding rotavirus vaccine, 2-dose 9vHPV vaccine, Men-ACWY vaccine in persons with HIV, Japanese Encephalitis vaccine, and Cholera vaccine
Influenza Vaccine
The 2015-2016 influenza season started later with less activity than other recent seasons, although it is not as mild of a season as 2011-2012. CDC testing of strains from infected individuals shows 75% to be type A, and the majority of those A strains is H1N1. Early reports of vaccine effectiveness so far are similar to previous seasons where vaccine was well matched to the circulating viruses.
The strains to be included in the 2016-2017 influenza vaccine were determined by VRBPAC, a subcommittee of the FDA, and are the same as those recommended by the World Health Organization. The four strains include the same H1N1 strain that was in this season’s vaccine, a new H3N2 type and two B virus strains which are the same as this season. The B virus strain that was only in the quadrivalent vaccine this season will be in the trivalent vaccine next season, and both B virus strains will be included in the quardivalent vaccine The strains in the trivalent vaccine will be A/California/7/2009 (H1N1)pdm09-like virus, A/Hong Kong/4801/2014 (H3N2)-like virus and B/Brisbane/60/2008-like virus. The quadrivalent will include those three strains and will also include B/Phuket/3073/2013-like virus.
The 2016-2017 influenza vaccine recommendations were discussed and were approved. Key changes include 1) wording about the timing of vaccine to clarify that vaccine should be offered optimally in the fall when supply is available through the month of October, and that it should continue to be provided as long as influenza virus is circulating and unexpired vaccine is available, and 2) reducing restrictions for providing flu vaccine to egg-allergic patients.
U.S. and international allergy societies have encouraged removal of guideline language differentiating the use of influenza vaccine in egg-allergic recipients compared to non–egg-allergic recipients, and discourage the practice of longer waiting periods following administration of influenza vaccine to egg-allergic recipients beyond those recommended for other patients.
Studies of LAIV in egg-allergic recipients have demonstrated no cases of anaphylaxis and no greater rate of mild, self-limiting allergic reactions than those seen in the general population.
The ACIP voted to remove the algorithm figure delineating a different process for egg-allergic recipients, and it changes language to allow for all forms of influenza vaccine (IIV, LAIV, RIV) to be used in egg-allergic recipients. It removes the 30 minute waiting period after receipt of the vaccine. The ACIP still is concerned that vaccine recipients who have had a previous reaction to egg consistent with anaphylaxis should have the vaccine administered in a medical setting by a health care provider proficient in the recognition and immediate management of a severe allergic condition. The wording for this part of the recommendation has not been finalized.
As with all vaccines, any allergic reaction following the administration of a vaccine is a contraindication against future receipt of that particular vaccine in that recipient.
Adjuvanted trivalent influenza vaccine for individuals ages 65 and above (FLUAD™) was approved by the FDA in 2015. It contains a squalene MF59 adjuvant and is supplied in pre-filled syringes.
Data from a study was presented by Protein Sciences, the manufacturer of Flublok® RIV4, demonstrating that compared to IIV during a highly mismatched season, such as the 2014-2015 season, RIV4 may be superior to IIV in preventing  cases of PCR confirmed influenza. Cross-protection to non-vaccine virus strains was speculated as a possible reason.
Also, RIV4 does contain a higher amount of each antigen (45 mcg) per dose compared to IIV4 (15 mcg).
Human Papilloma Virus (HPV) vaccine
In harmony with previous recommendation by the ACIP, the FDA approved the use of 9vHPV vaccine for males age 16-26 years in December 2015. Due to that change in the approved use, Merck will retire 4vHPV vaccine by the end of 2016 in the US. Seven million doses of the 9vHPV vaccine have been distributed so far.
 Zika Virus Update
The CDC has activated its Emergency Operations Center to respond to the identified Zika Virus outbreak and has determined its goals to be:
1.      Characterize the effects of Zika infection including the risk to pregnant women of fetal loss and congenital malformations including microcephaly , and the risk to the general population for Guillain-Barré Syndrome (GBS)
2.      Promote and evaluate interventions to prevent Zika including personal protection with insect repellant and contraception, vector control, prevention of transmission through blood, blood products and transplantation, and travel advisories
3.      Enable detection by development and distribution of Zika serologic laboratory diagnostics
4.      Develop a Zika virus vaccine
Evidence was presented in the ACIP meeting to inform the committee concerning future vaccine recommendations.
Rotavirus Vaccine
The representative from the NIH reported on a study showing Rotarix® and RotaTeq® to safely provide appropriate protection when a mixture of both products is used within the same vaccination series. The FDA and ACIP will need to review that data before making any changes in recommendations.
Human Papilloma Virus (HPV) vaccine
Europe has approved a 2-dose HPV vaccine schedule, and the World Health Organization (WHO) changed their recommendation in 2014 from a 3-dose schedule to a 2-dose schedule for those starting the series before age 15 years. A 9vHPV vaccine 2-dose schedule (0 months prime dose, 6 months boost dose) immunogenicity trial will be reviewed by the FDA in 2016. The basis of protection against HPV is neutralizing antibody, but a minimum protective level is not known. No loss of seroconversion is seen in trials with 2 doses rather than 3 doses, and Geometric Mean Titers (GMTs) in in a 2-dose schedule for girls and for boys age 9 to 14 years was non-inferior to a 3-dose series in young women age 16 to 26 years. The GMTs for girls given 2 doses was lower than the GMTs when girls were given 3 doses.         
Making sure there is a 6-month interval between doses allows the last dose to efficiently reactivate memory B cells. Duration of protection provided by 2 doses has not yet been assessed, but some studies seem to show that starting with a lower GMT with only 2 doses does not lead to a significant degradation of immunity over time.
The AICP will review post-licensure effectiveness of the 9vHPV vaccine as well as cost-effectiveness and programmatic considerations of a 2-dose schedule in their next meeting.
Meningococcal Conjugate 4-Valent
Due to studies showing that the risk of contracting meningococcal disease is 10 times higher in individuals with HIV than in the general population, and a higher case fatality rate in those with HIV, and in order to harmonize with AAP recommendations to provide Men-ACWY to HIV infected children > 2 years of age, the Meningococcal Work Group would like to propose adding HIV to the list of high risk conditions recommended to receive Men-ACWY.
Japanese Encephalitis Vaccine
The FDA is reviewing data supporting a booster dose in children. ACIP is considering strengthening the language of their adult booster recommendation to more closely reflect the language of European recommendations. Data was presented about a second booster dose 10 years after the first booster. While that is standard practice in Europe, there are no plans to present that data to the FDA for an expanded recommendation. The ACIP will incorporate the data about second booster in an updated MMWR, but do not feel the data is sufficient to support an off-label recommendation.
Cholera Vaccine
Pax-Vax has submitted a BLA for adults age > 18 years to the FDA for approval of a live attenuated oral vaccine to protect travelers against Vibrio cholera.
If you have any questions regarding immunization, feel free to contact Tamara Sheffield, MD, MPA, MPH, Medical Director, Community Health and Prevention, Intermountain Healthcare, at (801) 442-3946.