Ask the Experts: Summary of topics discussed at recent ACIP meeting
Committee addresses issues surrounding Japanese encephalitis, pertussis, and rotavirus vaccines, among others.
The Advisory Committee on Immunization Practice (ACIP) met in Atlanta, GA, on June 19–20, 2013. Complete minutes of the meeting will be published on the ACIP website.
Japanese encephalitis vaccine in children
The Japanese encephalitis (JE) vaccine JE-Vax (inactivated virus grown in mouse brain [JE-MB]—Biken) is no longer available. Ixiaro (Novartis) is an inactivated vero cell culture vaccine that is FDA approved for patients 17 years or older. It is given as a two-dose series (0 and 28 days) and may be boosted after 1 year. In May 2013, based on three clinical trials, FDA licensed Ixiaro for patients aged 2 to 16 years. The recommended dose is 0.25 mL administered at 0 and 28 days for patients aged 2 months to 2 years, 0.5 mL administered at 0 and 28 days for patients 3 years or older, and a booster after 1 year from completion of the series for patients older than 17 years. The booster dose has not been evaluated in children.
A representative from Intercell (a new company whose name will become Valneva) presented the pediatric clinical trial data. The seroprotection rates and adverse effects of Ixiaro were similar to JE-MB. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was applied to Ixiaro.
Based on the analysis, the working group determined that JE-VC is effective using seroprotection and safe in children aged 2 months to 16 years. The working group proposed to extent current recommendations from 2009 for children older than 2 months. These recommendations include spending 1 month or longer in JE endemic areas and short-term travelers if travel will be outside of urban areas or if outbreaks are occurring in the region. The vaccine is not recommended for short-term travelers whose visit is restricted to urban areas or does not occur during JE season.
General recommendations on immunization
Updates to the 2011 General Recommendations on Immunization were presented on one additional section: preventing and managing adverse reactions. All vaccine providers must have the capacity to recognize and manage an allergic reaction, including having a plan in place to get additional help. For patients who have had allergies previous, referral to a specialist is recommended unless testing and vaccination under a control protocol is possible. Egg allergy also was discussed, but management of patients with egg allergy is different for individual vaccines (i.e., influenza versus yellow fever vaccines). Allergy to thimerosal, neomycin, and latex also was discussed. Because these are contact-type allergies, vaccination is not contraindicated unless the allergies are severe. The complete, revised general recommendations document will be presented to ACIP for approval in June 2014.
Pertussis outbreaks are continuing, with the 2012 incidence the highest since 1955 and most cases occurring in adolescents. Tetanus–diphtheria–acellular pertussis (Tdap) vaccine coverage is about 78% in adolescents but only 12.5% in adults (according to 2011 statistics). The current recommendations for Tdap vaccination include (1) a single Tdap dose for all adolescents and all adults, (2) a Tdap dose for women during every pregnancy, and (3) a Td booster every 10 years (5 years for wound management). We can conclude that pertussis disease is increasing. We are seeing a resurgence of childhood disease despite high diphtheria–tetanus–acellular pertussis (DTaP) vaccine coverage, a reemergence of adolescent disease despite Tdap, and that the switch to acellular pertussis vaccines appears to be changing pertussis epidemiology. When antibody studies are performed, the tetanus and diphtheria titers decrease rapidly but remain elevated above protective levels. Correlates of protection for pertussis antibodies are not well defined; however, it appears that they decrease considerably at 2 to 4 years.
Cost-effectiveness studies were presented. Revaccination with Tdap at 16 years of age will prevent about 284 cases at a cost of about $77 million, while revaccination at 21 would prevent 168 cases at a cost of about $23.5 million. However, as these data are grossly underreported, estimates indicate 28,000 cases prevented with revaccination at age 16 years and 16,000 cases prevented with revaccination at 21 years.
The working group concluded that the data do not support a recommendation for a second dose of Tdap. Instead, ACIP recommends focusing on preventing pertussis in infants by vaccinating during pregnancy.
Human papillomavirus vaccine
Merck has maintained a pregnancy registry for more than 6 years. They have found no clustering of malformations and no pattern of birth defects and that the rates of spontaneous abortion, fetal deaths, and congenital anomalies are at or below background cases. Because they have exceeded the requirements of FDA, the registry will be discontinued.
ACIP's HPV statement will be updated to include a few changes, including the recommendation for vaccination at age 9 years for sexually abused children. Other considerations that must be decided by ACIP include HPV immunization in immunocompromised individuals, those with end-stage renal disease, health care providers working in laboratories, and those exposed to surgical smoke.
HPV vaccine has been used since 2006, and the vaccination rates have increased each year (29.5% for individuals aged 19–26 years in 2011); however, the increase has been limited in recent years. Postlicensure monitoring data continue to show good safety profile. Available data are showing an impact on decreasing disease using early and mild outcomes. Monitoring by CDC will continue.
The safety of rotavirus vaccine was evaluated by the working group. Two vaccines are available: pentavalent rotavirus vaccine (RV5; Rotateq—Merck), which has been on the market since 2006, and monovalent rotavirus vaccine (RV1; Rotarix—GlaxoSmithKline), which has been on the market since 2008. Diarrheal disease has decreased significantly since the vaccines were introduced. Neither the postmarketing studies nor evaluation by the Vaccine Safety Datalink has revealed an increase in intussusception caused by the vaccine. A recent analysis looking at RV1 and RV5 separately demonstrated a slight but significant increased risk of intussusception with RV1 (one additional case for every 18,713 doses given). A cluster analysis of the 10 cases showed that most occurred on days 3 through 6 following vaccination. No increase was seen with RV5. A recent evaluation of the Vaccine Adverse Event Reporting System showed an increase in intussusception due to RV5 of 33 additional cases per year in the United States; however, hospitalizations due to rotavirus diarrhea have decreased by 40,000 cases per year. Another evaluation was performed by FDA using its PRISM (Post-Licensure Rapid Immunization Safety Monitoring) program. The program showed a very slight increase with Rotateq, but not enough doses of Rotarix were administered to demonstrate a statistical increase. Nationally, rotavirus-positive tests have decreased by 73% and hospitalizations caused by rotavirus diarrhea have decreased by 30,000 to 70,000. In conclusion, the benefits of the vaccine greatly outweigh the risks.
The issues regarding herpes zoster vaccine discussed by the working group included evaluation of persistence, safety, booster doses, immunocompromised conditions, inactivated investigational vaccines, and adjuvanted vaccines. This information will be shared at a future ACIP meeting.
DTaP combination vaccines are in short supply (Pentacel—Sanofi and Pediarix—GlaxoSmithKline); however, DTaP is available for single use (i.e. not in combination with other vaccines).
Details regarding the 2012–13 influenza season were presented. Notably, the season peaked quickly, with type A virus dominating early and type B later in the season. A high rate of hospitalizations occurred, with the highest rate of visits for influenza-like illness since 1997 and the largest number of pediatric deaths since reporting began, excluding the pandemic years. A new strain, A(H7N9), appeared briefly in China, leading to 132 laboratory-confirmed cases with 39 deaths; however, no new cases have appeared since May 21, 2013.
The studies reported an adjusted vaccine efficacy of 52% (range 46% to 58%). Vaccination reduced outpatient visits by 44% due to A(H3N2), except in ages 9 to 17 years and 65 years or older, and by 62% due to type B. Vaccination also reduced inpatient visits with a reported efficacy of 57% to 72%.
The 2013–14 influenza recommendations will be published soon, with new additions including the approval of Fluzone Quadrivalent vaccine (Sanofi), information on the trivalent and quadrivalent vaccines, and minor changes to the egg allergy recommendations since the approval of Flublok (Protein Sciences).
Vaccine safety reporting did not show differences for previous influenza seasons.
The next ACIP meeting will be October 23–24, 2013, in Atlanta, GA.
Rothholz presents to ACIP on pharmacy-based immunizations
On June 20, 2013, during the ACIP meeting, APhA Chief Strategy Officer Mitchel Rothholz, BSPharm, MBA, provided an overview of the profession’s immunization activities. His presentation covered the history and focus of pharmacy-based immunizations, developing “immunization neighborhoods,” and training of immunizing pharmacists. Rothholz further discussed the immunization process of care, legal and regulatory considerations and barriers, scope of immunization activities, best practices, documentation and communication processes, and innovations, as well as what is on the horizon for pharmacists’ immunization activities. There was good dialogue during the question-and-answer session, and Rothholz and Dr. Stephan Foster (APhA Liaison Representative to ACIP) continued the discussion with the ACIP voting members during a focused group session. Questions raised included the role of pharmacists within travel health, documentation and record keeping, education and training, scope of practice, and the direction of the profession.