What is the latest World Health Organization (WHO) guideline for antirabies (rabies) vaccination?

Latest WHO Guidelines for Rabies Post-Exposure Prophylaxis (PEP)

The latest WHO recommendation for rabies post-exposure prophylaxis is a 4-dose vaccine schedule administered on days 0,3,7, and 14, along with rabies immunoglobulin infiltrated around the wound for previously unvaccinated individuals. 1

Components of Rabies Post-Exposure Prophylaxis

Wound Treatment

• Immediate and thorough cleansing of all bite wounds and scratches with soap and water for 15 minutes is the first critical step in rabies prevention 1, 2
• If available, a virucidal agent such as povidone-iodine solution should be used to irrigate the wounds 1
• Wound cleansing alone has been shown to markedly reduce the likelihood of rabies in animal studies 1
• Suturing should be avoided when possible to prevent deeper inoculation of the virus 1

Rabies Immunoglobulin (RIG)

• Human Rabies Immunoglobulin (HRIG) is administered only once at the beginning of PEP to previously unvaccinated persons 1
• The recommended dose is 20 IU/kg body weight 1, 3
• If anatomically feasible, the full dose should be infiltrated around and into all wounds 1
• Any remaining volume should be administered intramuscularly at a site distant from vaccine administration 1
• HRIG can be administered up to day 7 after the first vaccine dose if not given initially 1
• HRIG should never be administered in the same syringe or at the same anatomical site as the first vaccine dose 1
• The WHO now emphasizes that local wound infiltration of RIG is the primary mechanism of protection 4

Vaccination Schedule

• For previously unvaccinated individuals:

  • 4 doses of vaccine (HDCV or PCECV) administered intramuscularly (1.0 mL each) 1
  • Schedule: days 0,3,7, and 14 1, 5
  • For immunocompromised patients, a 5-dose schedule is still recommended (days 0,3,7,14, and 28) 1

• For previously vaccinated individuals:

  • Only 2 doses of vaccine are required (days 0 and 3) 1
  • HRIG is not necessary 1

Administration Considerations

• Vaccine should be administered in the deltoid area for adults and older children 1
• For younger children, the anterolateral aspect of the thigh may be used 1
• The gluteal area should never be used for vaccine administration due to risk of reduced immunogenicity 1, 3
• All PEP should begin as soon as possible after exposure, regardless of the time interval between exposure and initiation of treatment 1

Efficacy and Safety

• The 4-dose vaccine schedule has been proven safe and effective in inducing an adequate antibody response in all recipients 5
• Clinical trials with PCECV have demonstrated immunogenicity equivalent to HDCV 1
• Studies have shown that even 3 doses of rabies vaccine (days 0,3, and 7) can provide sufficient neutralizing antibody levels 6
• The intradermal 1-week vaccination regimen recommended by WHO carries important cost-, dose- and time-sparing benefits compared to older regimens 2

Special Considerations

• For pregnant women, rabies PEP should be administered as indicated, as the vaccine is safe and effective during pregnancy 7
• Postexposure prophylaxis should be initiated regardless of the length of delay since exposure, provided clinical signs of rabies are not present 1
• If the exposing animal is proven not to be rabid through appropriate laboratory testing, PEP can be discontinued 1

Common Pitfalls to Avoid

• Failure to adequately infiltrate wounds with HRIG, which is the primary mechanism of protection 4
• Administering vaccine in the gluteal area, which can result in diminished immune response 1
• Delaying PEP due to uncertainty about exposure - when in doubt, initiate treatment 3
• Not completing the full vaccination schedule, which is essential for adequate protection 2
• Inadequate wound cleansing, which is a critical first step in preventing rabies 1

The 4-dose vaccine schedule represents an evolution from previous 5-dose recommendations, offering similar protection with reduced healthcare visits, improved patient compliance, and lower costs 1, 5.