Influenza activity, herpes zoster vaccine, meningococcal vaccine, vaccine errors focus of recent ACIP meeting
Complete meeting minutes will be available soon on CDC's website
On February 22 and 23, the Advisory Committee on Immunization Practice (ACIP) met in Atlanta to discuss a variety of immunization topics, including influenza activity, herpes zoster, meningococcal vaccines, and vaccine errors, summarized below. Complete minutes of the meeting will be published on CDC’s National Immunization Program website in the near future (www.cdc.gov/vaccines/acip/index.html). ACIP’s next meeting is scheduled for June 20–21, 2017.
Influenza activity is currently at a moderate level, CDC noted, but the seasonal peak may not have occurred yet. The vaccine is well matched for the A(H3N2) virus, the primary circulating strain, with 96% of samples tested. In addition, influenza B may start to rise, as it usually appears toward the latter part of the season. Interim estimates of influenza vaccine effectiveness, recently published in the MMWR, show that overall effectiveness was 48% for all influenza viruses and 43% for A(H3N2). The recommendation for next year’s vaccine strains will be made in the coming weeks.
Another topic of discussion was Afluria’s (Seqirus) vaccine adverse events. The trivalent (TIV) formula was previously FDA approved for ages 5 and older, although ACIP recommended it for ages 9 years and older due to reports of an increase in febrile events. The quadrivalent (QIV) vaccine was recently FDA approved for 18 years and older, although Seqirus is seeking approval for use in 5- to 18-year-olds. Clinical trial results demonstrated that QIV fever rates were similar to the comparator TIV; however, there were no reports of more serious events associated with fever.
A study on use of high-dose influenza in nursing homes was presented. This large study of approximately 50,000 residents in 823 nursing homes demonstrated a number needed to treat of 81 given high-dose over standard dose to prevent one hospitalization. To put this in perspective on the basis of cost, if the vaccine cost $30, then 81 doses at approximately $2,430 would result in a much lower cost than the cost of hospitalization.
MedImmune presented data on effectiveness of the FluMist live-attenuated influenza vaccine (LAIV). While effectiveness for the 2015–16 season was low, as demonstrated in the CDC studies, results from other studies around the world showed varying rates. Two potential causes for reduced effectiveness were reduced replication of A(H1N1) in the LAIV strains and the formulation change to a QIV. There does appear to be a decrease in viral replication in the postpandemic A(H1N1) vaccine strains compared with prepandemic seasonal a(H1N1) strains.
A new candidate vaccine strain for the LAIV has been identified and will be studied in clinical trials during the 2017–18 season. ACIP is awaiting more clinical data directed against the A(H1N1) before adding LAIV to the recommendations. Predicting when an A(H1N1) predominant influenza season will occur is not possible, however, so it is unclear when the recommendations may change.
No CDC policy changes have been planned for next year’s influenza vaccine recommendation. ACIP continues to make no preference for one influenza vaccine over another.
Herpes zoster vaccine
HZ/su (Shingrix—GlaxoSmithKline) is an investigational, adjuvanted vaccine that has been discussed at the two previous ACIP meetings. Safety data from two studies published in the New England Journal of Medicine were summarized at the recent meeting. Local and systemic adverse symptoms were higher in vaccine recipients compared with placebo recipients, but most were mild to moderate and of short duration. Grade 3 adverse reactions were reported in 6% or fewer of patients depending on the symptom, and most patients with a grade 3 reaction to the first dose had a lower reaction to the second dose.
In addition, duration of protection, using cellular and humoral immunity studies, has been sustained above baseline for at least 9 years. Levels decrease over the first 4 years, then remain steady for up to 9 years. More data will be available in the near future, but vaccine efficacy has been demonstrated for at least 4 years, independent of age.
Manufacturing of Menomune (ACYW meningococcal polysaccharide vaccine—Sanofi Pasteur) has been discontinued, and all existing supplies will expire by September 2017. The other conjugated meningococcal ACWY vaccines are not FDA licensed for use in persons older than 56 years of age; however, CDC recommends their use in high-risk groups.
Because of certain diseases or continued exposure to outbreaks, booster doses of meningococcal ACWY vaccines for high-risk groups have been recommended every 5 years; however, no recommendations have been made for meningococcal B vaccines. Persons at high risk include those with complement deficiencies (an estimated 70,000), those taking eculizumab (Soliris—Alexion), patients with asplenia (estimated 100,000), microbiologists (estimated 100,000), and students during outbreaks of disease (estimated 180,000 students identified in 11 outbreaks). The estimated total number of individuals who fall into these groups is 270,000, excluding outbreaks. Antibody levels wane after 1 year following completion of the primary series of meningococcal B vaccines.
Booster studies of both meningococcal B vaccines (Trumenba—Pfizer and Bexsero—GlaxoSmithKline) demonstrated high levels 1 month following the booster dose, with minimal adverse effects reported. No data are available for intervals longer than 1 month after the booster dose. The ACIP working group recommended booster doses be harmonized with the recommendation for the meningococcal ACWY vaccine (i.e., every 5 years), except for repeat outbreak case exposures (>6 mo since completion of series). This recommendation will be discussed at future ACIP meetings.
In addition, future updates to the ACIP guidance for meningococcal outbreaks will include new case inclusion definitions, outbreak thresholds, the role of genotyping, vaccine selection guidance, recommendations for nonvaccine interventions (e.g., chemoprophylaxis), and re-evaluation of outbreak status.
The Immunization Safety Office, which monitors vaccine safety through the Vaccine Adverse Event Reporting System (VAERS), Vaccine Safety Data Link (VSD), and the Clinical Immunization Safety Assessment (CISA) Project, presented a report. From 2000 to 2013, 311,185 total vaccination errors were reported to VAERS, of which 20,585 were vaccination errors (7% of total).
According to VAERS, the most commonly reported errors were inappropriate schedule errors (27%), storage and dispensing errors (23%), and wrong vaccine (15%). Inappropriate schedule errors included wrong age and wrong timing, and storage errors included administering expired vaccine and storing at incorrect temperature. While not all errors caused health issues, 25% caused adverse health events.
A total of 92% of the errors were reported as nonserious, with injection site pain and redness and fever the most commonly reported symptoms. Although most of the errors do not appear to pose a risk, they do have an impact on costs, decreased protection, patient and provider inconvenience, and loss of confidence by the patient. CDC has many resources on its website to help reduce these errors.
For the full article, please visit www.pharmacytoday.org for the upcoming April 2016 issue of Pharmacy Today.