Mass vaccination against poliomyelitis in Mexico

Area of Science:

• Public Health
• Epidemiology
• Vaccinology

Background:

• Oral poliovirus vaccine (OPV) introduction in Mexico in 1959 faced challenges including misuse, poor coverage, and inadequate cold chain.
• Despite initial difficulties, a 1972 mass campaign achieved 70% coverage in children under five, leading to a sharp decline in reported polio cases.

Purpose of the Study:

• To analyze the impact of oral poliovirus vaccine (OPV) on poliomyelitis incidence in Mexico.
• To evaluate the effectiveness of vaccination strategies in reducing and controlling poliomyelitis.
• To outline future strategies for polio eradication in Mexico.

Main Methods:

• Retrospective analysis of poliomyelitis case data and vaccination coverage rates in Mexico from 1959 onwards.
• Assessment of the impact of mass vaccination campaigns and single-dose OPV administration on disease incidence.
• Review of current poliomyelitis control aims and future vaccination plans.

Main Results:

• Reported polio cases declined from 1.9 to 0.4 per 100,000 population after the 1972 mass campaign.
• Current poliomyelitis incidence is 0.1 per 100,000, a 96.7% reduction from the prevaccine era rate of 4.26 per 100,000.
• Single-dose monovalent type 1 OPV administered to 80% of the target population in 1981-1983 contributed to sustained low incidence.

Conclusions:

• Mass vaccination campaigns and strategic OPV use have been highly effective in reducing poliomyelitis in Mexico.
• Sustained high vaccination coverage is crucial for maintaining disease reduction and achieving polio eradication.
• Future efforts must focus on reaching unvaccinated populations in remote areas to eliminate remaining poliovirus reservoirs.