Meningococcal vaccine 76% effective for children under 5, study says

Complete immunization with a four-component, protein-based meningococcal serogroup B vaccine (4CMenB; Bexsero) has been found to be effective in preventing invasive serogroup B and non-serogroup B disease in children younger than 5 years of age. A study from Spain has shown.

In a cohort of 306 case patients and 1,224 matched controls, the efficacy of full vaccination (ie at least two doses of 4CMenB) against invasive meningococcal disease caused by any serogroup reached 76% (95% CI 57-87), reported Jesus Castilla, MD. , PhD, of the Instituto de Salud Pública de Navarra in Pamplona, ​​and colleagues.

For children who received one dose of the vaccine (11.4% of case patients and 24.3% of controls), efficacy was 54% (95% CI 18-74), they noted. New England Journal of Medicine.

Broken down by serogroup, full vaccination was 71% effective against meningococcal serogroup B disease and partial vaccination was 50% effective, while these rates were 92% and 58%, respectively, for non-serogroup B disease.

“This evidence may be useful in deciding whether to include this vaccine in the immunization programs of countries where invasive meningococcal disease in children is problematic and whose prevention is a priority,” Castilla and team wrote.

They noted that post-hoc analyzes showed no difference in efficacy among fully vaccinated children by number of vaccine doses (two or more than two) or time elapsed since receiving the last dose (<12 months vs. ≥12 months).

Of note, full vaccination was 71% effective (95% CI 43–86) against severe disease.

“In the analysis of the most severe cases, estimates of effectiveness were similar to those in the main analysis, findings that are particularly relevant given that prevention of severe disease is the primary objective of vaccination programs,” the authors wrote.

Previous studies looking at 4CMenB for serogroup W and serogroup C, W, and Y isolates have suggested efficacy against invasive disease from meningococcal serogroups other than B “and may be explained by the fact that the vaccine components are not unique to serogroup B,” Castilla’s group noted.

The 4CMenB vaccine contains four recombinant antigens, as well as porin A subtype P1.4 outer-membrane vesicles from strain NZ98/254, covering about a dozen serogroups, including A, B, C, W, X, and Y. Of these, serogroups B, C, and Y are most common in Europe and North America.

Meningococcal disease is rare and has a mortality rate of 10% to 15% in the United States. usually seen. -23, and adults over 85.

The CDC recommends vaccination for all preteen and adolescent girls in the US. The agency is currently recommending vaccination in Florida for an outbreak that primarily affects gay and bisexual men. In Europe, the 4CMenB vaccine is part of national routine immunizations in many countries, including Ireland, Italy and the UK, and has been part of the publicly funded vaccination schedule for all children in Spain since 2000.

For this study, Castilla and team included 306 patients (53.3% boys) under 5 years of age for whom there was a laboratory-confirmed PCR test. Neisseria meningitis From October 2015 to October 2019, 5.2% of them were fully vaccinated. Of these children, 79.4% had serogroup B disease, 33.3% had a clinical presentation of meningitis, 38.6% had sepsis, and 24.8% had both meningitis and sepsis.

Each case patient was matched to four controls by date of birth and province, for a total of 1,224 matched controls (50.7% boys), of whom 14.2% were fully vaccinated.

Because 4CMenB is available for private purchase in Spain, higher socioeconomic status may be associated with higher vaccination coverage, Castilla and team said, and higher socioeconomic status is associated with a lower incidence of meningococcal diseases.