The use of toxoid for the prevention of tetanus neonatorum. Final report of a double-blind controlled field trial. Reduction of neonatal tetanus by mass immunization of non-pregnant women: duration of protection provided by one or two doses of aluminium-adsorbed tetanus toxoid.
With a view to determining the effectiveness of a method for the control of tetanus neonatorum which would be independent of medical examination or care, a double-blind field trial covering 1618 women was conducted between 1961 and 1966 in a rural area of Colombia with an estimated existing tetanus neonatorum death rate of 11.6 per 100 births. The study group was given 1-3 injections of 1 ml of an aluminium-phosphate-adsorbed tetanus toxoid more than 6 weeks apart, and the control group a similar number of injections of an influenza-virus vaccine.There was no statistically significant difference between those in the two groups given one injection. Those in the control group given 2 or 3 injections had a tetanus neonatorum death rate of 7.8 deaths per 100 births, and the corresponding subjects in the study group had none. This difference is unlikely to have occurred by chance. Immunization of non-pregnant women in rural Bangladesh with two doses of aluminium-adsorbed tetanus-diphtheria toxoids reduced neonatal mortality by one-third during a period of 9-32 months after vaccination. The reduction in mortality rate was attributable almost entirely to a 75% lower mortality rate among 4-14-day-old infants, when tetanus was the predominant cause of death.In the period up to 20 months following vaccination, the reduction in deaths among 4-14-day-old infants after a single dose of tetanus-diptheria toxoids was about the same as that after two doses. However, beyond 20 months a single dose did not appear to provide protection.