Lactobacillus vaccine

Lore & Background

Lactobacillus vaccines were developed from aberrant strains of Lactobacilli isolated from women with acute colpitis. These strains are polymorphic, often shortened or coccoid, and fail to create an acidic environment that normally suppresses pathogens. Colonization with such strains correlates with heightened susceptibility to vaginal infections and frequent relapse after antimicrobial therapy. The vaccines work by stimulating the immune system to produce antibodies that inhibit the aberrant lactobacilli, allowing normal rod-shaped lactobacilli to recolonize and exert protective effects.

Reader's Guide

Lactobacillus vaccines have been studied primarily for bacterial vaginitis and trichomoniasis, with evidence from randomized, double-blind, placebo-controlled trials. In bacterial vaginitis, one study showed that 75% of vaccinated patients remained infection-free at 12 months versus 37% in the placebo group, following initial local antibiotic treatment. For trichomoniasis, vaccination reduced reinfection rates to 0% in one study and 3.1% in another, compared to 33.3% and 21.6% in placebo groups. Efficacy is weaker in vaginal candidiasis, where only 17% of treatment-resistant patients healed. The vaccines have also been investigated for preventing low birth weight and preterm birth: in one study, vaccinated pregnant women had a 10.4% rate of low birth weight versus 24.1% in controls, and a preterm birth rate of 7.1% versus 12.2% in a larger prospective study. No studies using modern formulations have been conducted for recurrent urinary tract infections, though initial success was reported in pregnant women.

Did You Know?

• The aberrant lactobacilli used in the vaccines are polymorphic, often shortened or coccoid, and do not produce an acidic vaginal environment.
• In a 12-month study, 75% of vaccinated patients remained free from bacterial vaginitis versus 37% in the placebo group.
• For trichomoniasis, one study reported zero reinfections in the vaccinated group compared to 33.3% in the placebo group over months 4 to 12.
• Vaccinated pregnant women had a preterm birth rate of 7.1% versus 12.2% in controls in a prospective study of 1852 vaccinated women and 1418 controls.