June 27, 2018, 01:41 pm Chris Crawford – During the June 20-21 meeting of the CDC's Advisory Committee on Immunization Practices (ACIP), the group reaffirmed its recommendation to include live attenuated influenza vaccine (LAIV; FluMist) in its guidance for the 2018-19 influenza season. ACIP members also outlined new guidelines for use of the anthrax vaccine adsorbed (AVA; BioThrax) for post-exposure prophylaxis.
Additional updates were offered on HPV, mumps, zoster and pneumococcal vaccines, AAFP liaison to the ACIP Pamela Rockwell, D.O., of Ann Arbor, Mich., told AAFP News.
The ACIP reaffirmed the vote taken at its February meeting to officially recommend that all patients ages 6 months and older without contraindications should receive influenza vaccine during the 2018-19 influenza season; clinicians may administer any licensed, age-appropriate influenza vaccine, including LAIV (for patients ages 2-49 without contraindications), inactivated influenza vaccine and recombinant influenza vaccine.
The AAFP plans to review the evidence presented at the June ACIP meeting to determine its stance on using LAIV for the 2018-19 flu season.
AAFP News The ACIP had recommended against the use of LAIV for the 2016-17 and 2017-18 flu seasons because the vaccine's influenza A (H1N1) component wasn't protecting people against that influenza strain.
Rockwell told AAFP News after the ACIP's February meeting that FluMist manufacturer MedImmune, a subsidiary of AstraZeneca, had replaced the influenza A (H1N1) component with a more effective component for the upcoming flu season.
ACIP members also announced during last week's meeting that an influenza sub-working group for maternal influenza vaccine had been created and met for the first time in April.
Finally, GlaxoSmithKline (GSK) presented data on its Fluarix Quadrivalent vaccine. In January, the FDA approved GSK's application to extend the vaccine's age range to include children ages 6-35 months.
Next up, the ACIP voted unanimously to approve new guidelines for using AVA for post-exposure prophylaxis should an anthrax bioweapon be used in a mass event. The new guidance specifically addresses what to do if availability issues for AVA arise.
The routine recommendation for AVA for pre-exposure prophylaxis is five doses given at zero, one, six, 12 and 18 months subcutaneously, followed by an annual booster. Post-exposure AVA is recommended in a three-dose series given at zero, two and four weeks subcutaneously with co-administration of antibiotics for 60 days.
The newly proposed guidelines offer potential alterations in the route of administration and a shortened course of antibiotics, along with dosing changes for the vaccine.
First, an intramuscular route of administration may be used if the preferred subcutaneous route presents clinical, operational or logistical challenges that may delay or prevent effective vaccination.
Second, if the available AVA supply is inadequate for post-exposure prophylaxis, the vaccine may be administered in either two full or three half doses to expand vaccine coverage to all affected individuals.
Finally, for immunocompetent individuals, antibiotic post-exposure prophylaxis may be discontinued at 42 days after the first vaccine dose, if needed, or two weeks after the last vaccine dose, whichever comes later.
An update from the HPV work group noted that an application had been submitted to and accepted by the FDA to expand the age indication for nine-valent HPV vaccine (HPV9; Gardasil 9) through age 45 in both males in females.
Data from clinical studies presented supported use of HPV9 for patients ages 27-45; full analyses are expected from the work group in mid-2019, said Rockwell.
"The HPV work group again reviewed safety issues since HPV9 has been licensed and found no new concerns," she explained. "There also was strong support from the work group for harmonization of schedules for males and females."
The CDC's current recommendation for HPV9 is a two-dose schedule for patients ages 11-12, but dosing can begin as early as age 9 or as late as 13-14. The second dose should be administered six to 12 months after the first dose, with a minimum interval of five months.
Routine vaccination for previously unvaccinated females through age 26 and for previously unvaccinated males through age 21 is recommended, Rockwell said. Routine vaccination for males with high-risk conditions or who wish to be vaccinated between ages 22-26 also is recommended. For patients ages 15-26 initiating the HPV9 vaccine series, the recommended immunization schedule is three doses given at zero, one to two, and six months.
Furthermore, patients in this older age range who initiated the series before age 15 with one or two doses but did not complete the series require only one additional dose for adequate immunization.
The Mumps work group offered an update on policy options for administering a third dose of the measles, mumps and rubella (MMR) vaccine if an outbreak occurs.
Patients identified as being at increased risk are advised to seek vaccination through routine immunization channels.
Public health authorities might choose to expand their response to include vaccination campaigns or clinics in certain situations, Rockwell said, such as when case counts are increasing despite recommendations, when access to vaccine is poor or vaccine uptake is low in the group at increased risk, or when the group at increased risk includes hard-to-reach or vulnerable populations.
Further implementation guidance for a third MMR dose includes advice for patients with unknown vaccination history, those who have received fewer than two previous doses, and those who have evidence of presumptive immunity (born before 1957) or evidence of immunity through serology.
No additional dose is advised for patients who received three or more doses before the outbreak or for those who received a second dose during the outbreak.
"The bottom line for all those at risk during an outbreak: patients vaccinated with two MMR doses before the outbreak should receive a third dose regardless of the time since the second dose, following the guidelines for the minimum interval for live virus vaccines," Rockwell said.
Public health authorities may recommend a dose without verification of vaccination history to avoid delays, she added.
Rockwell said the group is working to develop transmission models to examine factors that impact the size and duration of an outbreak and collect data to measure the duration of antibody response five years after the third dose is given.
She said the work group planned to compare the antibody activity after the second and third doses of MMR, assess the differences between antibody responses to vaccine versus circulating wild-type mumps strains, and monitor the mumps incidence among populations with third-dose vaccine recipients to better characterize the duration of protection after the third dose.
The ACIP gave the newer herpes zoster subunit vaccine (HZ/su; Shingrix) a preferential recommendation over the herpes zoster live (Zostavax) vaccine for adults 50 and older at its October 2017 meeting.
"Because Shingrix has been so popular and in high demand, GSK has now implemented order limits due to limited supply, and there might be shipping delays for the rest of 2018," Rockwell said. "However, the company plans to release doses to all customer types on a consistent, predictable schedule for the remainder of the year."
Rockwell added that Shingrix manufacturer GSK said it has enough supply this year to vaccinate more U.S. patients than were vaccinated last year.
Rockwell said that during the ACIP's meeting in October, the Pneumococcal work group plans to share data on the 13-valent pneumococcal conjugate vaccine (PCV13) and its impact on all-cause pneumonia.
"Scientists are looking at whether after many years now of vaccinating children against pneumococcal disease and the subset of adults who have received the extra PCV13, if this will continue to be a cost-effective method of protection in (older populations)," she said.
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