ACIP Recommends 2 Vaccines for Some Travelers BY MARIE ROSENTHAL, MS
T
he Advisory Committee on Immunization Practices (ACIP) voted to recommend two vaccines for people who travel abroad to areas with endemic disease. The first set of recommendations concern a rare disease transmitted by ticks, tickborne encephalitis (TBE). The ACIP voted to recommend TBE vaccine (TicoVac, Pfizer) for people 12 months of age and older, who may be exposed to the virus by being in TBE-endemic areas or who could be exposed through laboratory work, regardless of where they live.
TBE is caused by a rare but serious flavivirus related to the Powassan virus, which causes neuroinvasive disease. The virus is transmitted to people through the bite of the Ixodes species of tick, which is focally endemic in parts of Europe and Asia. About 5,000 to 10,000 cases are reported each year. The risk is seasonal and typically lasts from April to November. The incidence varies from country to country, within countries and year to year, according to Susan Hills, MBBS, MTH, a medical epidemiologist at the Arborviral Diseases Branch, CDC. There is no cure or specific treatment for TBE, but management of symptoms is possible. The risk is low to Americans, Ms. Hills added. Only 11 cases occurred in U.S. travelers from 2001 to 2020, and nine cases among military personnel assigned overseas between 2006 and 2020. Still, one in three people can have long-lasting effects after exposure that include cognitive changes, muscle weakur. ness or permanent paralysis, and in rare cases, death can occur. to A factor limiting exposure is that a person must come into p le contact with the ticks, so a person’s planned activities while eir exposure. visiting an endemic area are key to their ations for the vaccine: The ACIP made three recommendations eople who • TBE vaccine is recommended for people are moving to or traveling to a TBE-ve exposure to endemic area and will have extensive or activities and itinerary. itinerary ticks based on their planned outdoor • TBE vaccine may be considered for those traveling or moving to a TBE-endemic area who might engage in outdoor activities in areas where ticks are likely to be found. The decision to vaccinate should be based on an assessment of their planned activities and itinerary, risk factors for a
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poorer medical outcome, and personal perception and tolerance of risk. • TBE vaccination is recommended for laboratory workers with a potential exposure to the TBE virus. The FDA approved TicoVac on Aug. 13, 2021, for active immunization to prevent TBE in individuals 12 months of age and older. In clinical trials, the safety and immunogenicity of the TBE vaccine were assessed in two age groups (12 months to 15 years, and 16 years and older). In these studies, seropositivity rates were 99.5% in the younger group and 98.7% to 100% in people 16 years and older following three doses. The most common adverse reactions in both age groups were local tenderness, headache, local pain, fever, restlessness, fatigue and muscle pain. ACIP voting member Camielle Nelson Kotton, MD, an associate p professor of medicine at Harvard Medical School, in Boston, sa said she was glad for the recommendation, because it provided flexibility and a mechanism for shared decision m making between the healthcare provider and patient. Wilber H. Chen, MD, MS, a professor of medicine at the Cente Center for Vaccine Development and Global Health, University of Maryland School of Medicine, in Baltimore, also was glad for the recommendations, but for a different reason: global warming. “Even though we don’t perceive that the burden of TBE is large and it might be difficult to perhaps implement this vaccine because of the complexity of trying to understand where the tick habitat is, with the trend of global warming, we are seeing tick habitats and mosquito habitats and flaviviruses continue to circulate, so it’s just a reminder that flaviviruses— among which are dengue, West Nile, yellow fever—continue to scorch the world,” said Dr. Chen, who is also a voting member of ACIP. “So, I think we will see these types of vaccines becoming more and more important.” The second travel vaccine that was recommended was lyoph-
ilized CVD 103 HgR cholera vaccine (Vaxchora 103-HgR (Vaxchora, Emergent) Emergent), which is now recommended for children and adolescents 24 months to 17 years of age, who are traveling to an area with active cholera transmission. Fourteen of the 15-member panel voted in favor of the vaccine. Dr. Chen abstained because of a continued on page 18
