Use of a Modified Preexposure Prophylaxis Vaccination Schedule to Prevent Human Rabies: Recommendations of the...

Human rabies is an acute, progressive encephalomyelitis that is nearly always fatal once symptoms begin. Several measures have been implemented to prevent human rabies in the United States, including vaccination of targeted domesticated and wild animals, avoidance of behaviors that might precipitate an exposure (e.g., provoking high-risk animals), awareness of the types of animal contact that require postexposure prophylaxis (PEP), and use of proper personal protective equipment when handling animals or laboratory specimens. PEP is widely available in the United States and highly effective if administered after an exposure occurs. A small subset of persons has a higher level of risk for being exposed to rabies virus than does the general U.S. population; these persons are recommended to receive preexposure prophylaxis (PrEP), a series of human rabies vaccine doses administered before an exposure occurs, in addition to PEP after an exposure. PrEP does not eliminate the need for PEP; however, it does simplify the rabies PEP schedule (i.e., eliminates the need for rabies immunoglobulin and decreases the number of vaccine doses required for PEP). As rabies epidemiology has evolved and vaccine safety and efficacy have improved, Advisory Committee on Immunization Practices (ACIP) recommendations to prevent human rabies have changed. During September 2019-November 2021, the ACIP Rabies Work Group considered updates to the 2008 ACIP recommendations by evaluating newly published data, reviewing frequently asked questions, and identifying barriers to adherence to previous ACIP rabies vaccination recommendations. Topics were presented and discussed during six ACIP meetings. The following modifications to PrEP are summarized in this report: 1) redefined risk categories; 2) fewer vaccine doses in the primary vaccination schedule; 3) flexible options for ensuring long-term protection, or immunogenicity; 4) less frequent or no antibody titer checks for some risk groups; 5) a new minimum rabies antibody titer (0.5 international units [IUs]) per mL); and 6) clinical guidance, including for ensuring effective vaccination of certain special populations.