Group B meningitis poses a serious health risk to children, but the disease is vaccine preventable. A recent study published in the New England Journal of Medicine evaluated the efficacy of vaccination with the multicomponent meningococcal group B (4CMenB) vaccine for actual versus expected incidence of the disease in young children with positive results.1
The 4CMenB vaccine became a part of the publicly funded immunization program in the United Kingdom in September 2015. It was given in a 2-dose priming schedule in infants along with a 12-month booster. The researchers compared the observed incidence of meningococcal group B disease with the expected incidence, which was based on the incidence during the 4-year prevaccination period in equivalent cohorts. They also used disease trends from cohorts of children aged younger than 5 years who were ineligible to get the vaccine.
During the study period, the number of children receiving the 4CMenB vaccine remained high, with data in the first 3 months of 2018 showing that 92.5% of children had received the primary immunizations by their first birthday and 87.9% of children had completed the 3-dose series by their second birthday.
4CMenB proved effective in reducing cases of group B meningitis
From the start of 4CMenB’s inclusion in the program in September 2015 to August 2018, the incidence of meningococcal disease was significantly lower in the vaccine-eligible cohorts than the expected incidence (63 observed cases compared with 253 expected cases; incidence rate ratio, 0.25; 95% confidence interval [CI], 0.19-0.36). Additionally, there was a 75% reduction of incidence of meningococcal disease in the age groups that were considered fully eligible to receive the vaccine.
In the 2-dose priming schedule for infants, the adjusted vaccine effectiveness was 52.7% (95% CI, −33.5 to 83.2. The effectiveness rose with the 2-dose priming schedule plus a booster at age 1 year to 59.1% (95% CI, −31.1 to 87.2). Over the course of the 3 years studied, a total of 169 cases of meningococcal group B disease occurred in the vaccine-eligible cohorts and an estimated 277 cases (95% CI, 236-323) were prevented.
The researchers concluded that the 4CMenB vaccine had a positive effect against meningococcal group B disease and that protection from the disease lasted at least 2 years after receiving 3 doses. Interestingly, in the same issue of the New England Journal of Medicine, there was an Australian study that examined whether the 4CMenB vaccine can build herd immunity in teenagers.2 The results indicated that the vaccine does not, making it even more imperative that children receive the vaccine when they are young.
1. Ladhani SN, Andrews N, Parikh SR, et al. Vaccination of infants with meningococcal group B vaccine (4CMenB) in England. N Engl J Med. 2020;382(4):309-317.
2. Marshall HS, McMillan M, Koehler AP, et al. Meningococcal B vaccine and meningococcal carriage in adolescents in Australia. N Engl J Med. 2020;382(4):318-327.