Mass vaccination campaign against rabies: are dogs correctly protected? The Peruvian experience.

In a mass vaccination campaign conducted in Peru in March 1985, 270,000 dogs (65% of the estimated dog population) were vaccinated over the course of 1 month with an inactivated tissue culture vaccine. Since that time no human rabies cases have been reported; in addition, the number of animal rabies cases has declined to only three from a previous mean of 292 cases per year since 1980. A serologic survey was also done to determine the immune response among randomly selected vaccinated dogs, with titers determined 3, 6, 9, and 12 months after vaccination. Twelve months after vaccination, 97% of the dogs had a rabies neutralizing antibody titer of greater than or equal to 0.5 IU/mL, and 87% had a titer of greater than or equal to 1.0 IU/mL. Thus, this tissue culture rabies vaccine given under field conditions induced antibodies that lasted for at least 1 year in 97% of vaccinated dogs.