ACIP Updates Japanese Encephalitis, Anthrax Vaccine Guidance

Group Considers Data on Various Other Immunization Topics

March 06, 2019, 02:00 pm Chris Crawford – During the Feb. 27-28 meeting of the CDC's Advisory Committee on Immunization Practices (ACIP), the group voted to update its recommendations for the Japanese encephalitis (JE) vaccine.

The risk for JE is very low for most U.S. travelers -- even those who travel to countries where the disease is endemic, she said. However, some travelers will be at increased risk of infection based on their planned itinerary and other factors.

The ACIP first voted to update its policy recommendation for U.S. travelers to read: "JE vaccine is recommended for persons moving to a JE-endemic country to take up residence longer-term (e.g., more than or equal to one month), travelers to JE-endemic areas and frequent travelers to JE-endemic areas."

Furthermore, the group said JE vaccine should be considered for shorter-term (e.g., less than one month) travelers with an increased risk of JE based on planned travel duration, season, location, activities and accommodations. Vaccination also should be considered for travelers to JE-endemic areas who are uncertain of specific duration of travel, destinations or activities.

The ACIP said JE vaccine isn't recommended for travelers with very low-risk itineraries, such as shorter-term travel limited to urban areas or travel that occurs outside of a well-defined JE virus transmission season.

Next, the group voted to recommend an accelerated schedule of the JE vaccine in adults ages 18-65, with two doses administered on days 0 and 7-28 -- a change from the previous recommendation. "JE vaccine used to be recommended for adults ages 18-65 at zero and 28 days," Rockwell clarified.

Finally, the ACIP voted to address JE booster doses by lowering the age to include children and strengthening the current permissive booster dose recommendation.

The updated recommendation says: "A booster dose (i.e., third dose) should be given at more than one year after completion of the primary JE-VC series if ongoing exposure or re-exposure to JE virus is expected."

"I believe the final language on the booster dose will also clarify that it now includes children," Rockwell said, by specifically adding the word "children" to the recommendation.

Anthrax Vaccine

The fourth vote of the meeting also was unanimous and recommended that a pre-exposure prophylaxis booster dose of anthrax vaccine adsorbed (AVA) be given every three years to patients not currently at high risk for exposure to Bacillus anthracis who have been previously primed with AVA and wish to maintain protection.

"Basically, this policy updates the booster recommendation to be given every three years to maintain your immune status," Rockwell said, whereas the previous recommendation was for annual boosters.

AVA is the only licensed preventive vaccine for U.S. adults at increased risk for exposure to B. anthracis, such as certain laboratory workers who work with B. anthracis, people who handle potentially infected animals and some military personnel (determined by the Department of Defense), Rockwell said.

The routine recommendation for AVA vaccination has been five doses given at zero, one, six, 12 and 18 months subcutaneously, followed by an annual booster -- now updated to every three years -- for those who require ongoing protection.

Additional Notes

Other noteworthy items from the meeting include the fact that the HPV vaccine work group is examining data on extending the immunization's age recommendation to age 45 and will present that information at the June ACIP meeting in preparation for a vote on the topic.

"This might end up being what used to be called a 'Category B recommendation,' which is now called 'individual decision-making,'" Rockwell said. "The work group also plans to address the harmonization of male and female recommendations for catch-up HPV vaccines."

Another presentation at the meeting highlighted a new hexavalent vaccine, Vaxelis, that was developed as a partnership between Sanofi Pasteur and Merck and that the FDA approved Dec. 21. The vaccine protects against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B infection and invasive disease due to Haemophilus influenzae type b.

The combination vaccines work group plans to apply an evidence framework during the June ACIP meeting to decide whether the hexavalent vaccine should be included as an option in the Vaccines for Children program for the infant series at 2, 4 and 6 months of age.

It also will consider whether the vaccine should be preferentially recommended for the American Indian/Alaska Native population.

"If approved and recommended, I would consider Vaxelis for my patients because it would mean one less injection for infants at 4 months of age, given the types of combination vaccines used in my practice," Rockwell said. "Depending on what combination of vaccine products one uses in their practice, using Vaxelis could reduce (the total number by) anywhere between one and four injections."

Also during the February meeting, the pneumococcal vaccines work group presented data showing that giving PCV13 to adults 65 and older in addition to PPSV23 has been shown to be helpful.

"However, the herd effect from children getting PCV13 now has been shown to be beneficial," Rockwell noted, "and some academics are proposing we stop giving adults PCV13 based on the data presented."

Rockwell said she spoke up during this discussion at the meeting, saying the data (which is only about four years old now) failed to capture everyone who wasn't hospitalized and potentially benefited from receiving PCV13.

"This could be because the PCV13 vaccine either allowed them to be diagnosed with an outpatient pneumonia and they never got sick enough for a hospitalization or they never required hospitalization for other reasons due to pneumococcal infections," she said, adding that the data could also be affected by physicians typically taking a year or longer to adopt new guidelines.

To further complicate things, two phase 3 trials are currently being conducted on new adult pneumococcal vaccines (PCV15 and PCV20), Rockwell said, which would offer broader coverage for pneumococcal disease.

"Theoretically, recommendations to adopt these vaccines could actually replace (those for) PCV13 in the future," she said. As the AAFP's liaison to the ACIP, said Rockwell, she was asked to gather input for this topic from the Academy and its family physician members.

At an upcoming ACIP meeting, the meningococcal vaccine work group will present policy options for a vote regarding use of that vaccine in patients with complement deficiency, complement inhibitor use or asplenia, as well as for microbiologists and patients at increased risk during an outbreak.

Regarding GlaxoSmithKline's recombinant zoster vaccine, Shingrix, Rockwell said the zoster work group presented an update on monitoring reported safety issues but said it found insufficient evidence at this time to determine whether there was a safety problem with the vaccine.

Four cases of Guillain-Barré syndrome had been reported as possibly associated with use of the vaccine, but the work group said two cases had been ruled out, one case was only possibly associated and one is still under investigation. Currently, the CDC's Immunization Information Systems in Minnesota, Michigan, Oregon, North Dakota, Wisconsin and New York City are observing zoster vaccine uptake.

Finally, the hepatitis work group (of which Rockwell is a member) reviewed HIV infection as an indication for hepatitis A vaccination regardless of other indications for vaccination.

"The work group consensus was to recommend this intervention, but the vote on this topic will come at a future meeting," Rockwell said.

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