The rabies virus is transmitted through direct contact with infectious tissue or fluids from infected mammals. These include nerve tissue, saliva, respiratory fluids, and tears. Direct contact means broken skin or mucous membranes of the eyes, mouth or nose.5 The incubation period is between 20 and 60 days but can be several years before the virus enters the central nervous system. The disease manifests as angry rabies that causes hyperactivity, hydrophobia, and sometimes aerophobia, or paralytic rabies that begins a paralysis that begins at the site of transmission. Once clinical symptoms appear, survival is rare and associated with permanent disability and severe brain damage.4,6.7 Fortunately, vaccinations have almost eliminated death from rabies.7th
Recommendations for prophylaxis and vaccination
According to CDC guidelines, the population of the United States as a whole does not require any vaccinations. Travelers to other countries, particularly Africa and Asia, should visit the CDC Poxvirus and Rabies Branch website (https://www.cdc.gov/rabies/resources/countries-risk.html) to assess their risk of rabies exposure and their need for post-exposure prophylaxis (PEP).4th The PEP consists of 1 dose of rabies immunoglobin and 4 doses of rabies vaccination on days 0.3, 7 and 14.8th
Travelers should consider pre-exposure prophylaxis (PrEP) vaccination if planned activities include encounters with pets or wildlife, if they are in an area where canine rabies is common for more than a month, or if they visit remote areas in where medical care can be delayed.4th The CDC categorizes risks into 3 categories: continuous, frequent and infrequent. The level of risk is determined by the level of contact with the rabies virus, such as: or working with animals in areas where rabies is not endemic (rare risk).9
In addition to these categories, adventure travelers, campers, speleologists, and rural visitors are among the people who are more likely to encounter rabid animals. Consider vaccinating children as they may not report bites or get more severe bites.4th
The PrEP vaccination was recently updated to 2 doses on days 0 and 7 instead of 3 doses on days 0, 7 and 21 or 28 for immunocompetent persons aged 18 and over, instead of a titer control in immunocompetent persons aged 18 and over with an increased and persistent risk of one Rabies exposure. This booster dose should be given on the 21st day at the earliest and no later than 3 years after the 2-dose PrEP vaccinations.10
Specific features of the vaccine
If you are considering a PrEP vaccination, you do not have to postpone mild illnesses such as colds.
Consider delaying vaccination for people with AIDS / HIV, a history of allergic reactions to the rabies vaccine, cancer or severe allergies, or people who are breastfeeding, pregnant, or taking immunocompromising drugs. After exposure to rabies, all patients should be vaccinated regardless of any of the above conditions.7th The side effects of the vaccine are usually mild and may include dizziness, headache, muscle aches, pain, redness and swelling at the injection site, stomach pain, and upset stomach. The symptoms are self-limiting and go away within a few days.8th
The same vaccine is used before and after exposure. The 2 rabies vaccines available in the US are the human diploid cell vaccine (Imovax rabies; Sanofi Pasteur SA) and the purified chicken embryo cell vaccine (RabAvert; GlaxoSmithKline).7.11 Both are given intramuscularly and contain inactivated rabies virus.5 In the event of a shortage or when a vaccine is not available, the vaccines are interchangeable. Once one patient has started a series with a vaccine, the other can be used to complete both a pre- and post-exposure series.
PrEP should be considered when traveling to areas where there is a high likelihood of encountering domestic or wildlife, or when working in an area of ââhigh risk. PrEP vaccination does not eliminate the need for post-exposure treatment, but it simplifies treatment and provides protection for those unable to access higher quality care quickly.
Kathryn Lincoln, PharmD, BCIDP, is a clinical infectious disease pharmacist for Olathe Health in Kansas City, Missouri.
Jerline Hsin, PharmD, BCOP, BCPS, is head of the hematological oncology pharmacy at Tripler Army Medical Center in Honolulu, Hawaii.
1. Wallace RM, Petersen BW, Shlim DR. Travel-related infectious diseases – rabies. In: CDC Yellow Book 2020. Oxford University Press; 2019: 169-392. Accessed on August 13, 2021. https://wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/rabies
2. Rabies and your pet. American Veterinary Association. Retrieved on August 14, 2021. https://www.avma.org/resources/public-health/rabies-and-your-pet
3. Which animals did you come into contact with? CDC. June 11, 2019. Accessed August 13, 2021. https://www.cdc.gov/rabies/exposure/animals/index.html
4. Rabies. CDC. Updated September 25, 2020. Accessed August 13, 2021. https://www.cdc.gov/rabies/index.html
5. Manning SE, Rupprecht CE, Fishbein D, et al .; Advisory Committee on Immunization Practices Centers for Disease Control and Prevention (CDC). Human Rabies Prevention – United States, 2008: Recommendations of the Advisory Committee on Vaccination Practices. MMWR recommended rep. 2008; 57 (RR-3): 1-28.
6. Rabies. World health organization. May 17, 2021. Accessed August 14, 2021. https://www.who.int/news-room/fact-sheets/detail/rabies
7. RabAvert. Prescribing information. GlaxoSmithKline; 2018. Accessed August 14, 2021. https://www.fda.gov/files/vaccines%2C%20blood%20%26%20biologics/published/Package-Insert—RabAvert.pdf
8. Vaccines after illness. U.S. Department of Health and Social Welfare. Updated April 29, 2021. Accessed August 14, 2021. https://www.vaccines.gov/diseases/rabies
9. Pre-exposure vaccinations. CDC. Updated April 22, 2011. Retrieved August 14, 2021. https://www.cdc.gov/rabies/specific_groups/travelers/pre-exposure_vaccinations.html
10. ACIP recommendations. CDC. Updated July 13, 2021. Accessed August 14, 2021. https://www.cdc.gov/vaccines/acip/recommendations.html
11. Imovax rabies. Prescribing information. Sanofi Pasteur SA; 2019. Accessed August 14, 2021. https://www.fda.gov/media/75709/download