Vaccination of BALB/c mice against Brugia malayi and B. pahangi with larvae attenuated by gamma irradiation.

The vaccination with radiation-attenuated infective larvae of Brugia malayi and B. pahangi was attempted and evaluated in BALB/c mice. Two weeks after intraperitoneal infection with 100 3rd stage larvae, the worms of both species of Brugia were recovered in the peritoneal cavity of BALB/c mice. The average recovery was more than 20% in both Brugia infections. Groups of 10 mice were vaccinated subsequently three times with 100 3rd stage larvae of B. malayi or B. pahangi attenuated by 20 krad gamma irradiation and challenged with the homologous species. Vaccinated mice showed a 95.5% reduction in recovered worms in the challenge infection with B. malayi as compared to the infection in non-vaccinated controls, and a 93.8% reduction in the B. pahangi group.