[VA-MENGOC-BC vaccine: its impact on meningococcal disease in children 1-4 years old]

Area of Science:

• Public Health
• Vaccinology
• Epidemiology

Background:

• The VA-MENGOC-BC vaccine has been integral to Cuba's National Immunization Program (NIP) for infants since 1991.
• Evaluating vaccine effectiveness in high-risk pediatric populations is crucial for public health strategies.
• Meningococcal disease (MD) poses a significant risk to young children.

Purpose of the Study:

• To assess the impact of the VA-MENGOC-BC vaccine on meningococcal disease morbidity and mortality in Cuban children aged 1-4 years.
• To analyze trends in disease incidence and lethality following vaccine implementation within the NIP.

Main Methods:

• A descriptive epidemiological study was conducted.
• Data from 145 cases of meningococcal disease between 1991 and 1996 were analyzed.
• Vaccine histories, including timing of immunization, were examined for cases and deaths.

Main Results:

• A consistent decreasing trend in the incidence density (ID) of meningococcal disease was observed across all age groups, with the most significant decline in one-year-old infants (ID of 10.8 per 100,000 children/years by 1996).
• The age distribution of cases shifted from predominantly one-year-olds at the program's start to three- and four-year-olds by the study's end.
• Mortality density also declined significantly after 1993, though two-year-olds faced the highest risk of death; overall lethality was 24.1%, lowest in one-year-olds (14.3%).

Conclusions:

• The VA-MENGOC-BC vaccine, as part of the NIP, has demonstrably altered the behavior of meningococcal disease in high-risk children.
• The observed reductions in incidence and mortality strongly support the continued administration of the VA-MENGOC-BC vaccine.
• Vaccination, even when administered over a year prior to illness, appears to confer protection, though further analysis of optimal timing may be warranted.