A new study shows that a new 4-component meningococcal (4CMenB) vaccine for teenagers is effective when administered on a schedule of 2 doses from 1 to 6 months apart. María Elena Santolaya, from the Department of Pediatrics, University of Chile, Santiago, and colleagues performed the study, which was published online January 18 in the Lancet.
The authors of the study write, “Development of a broadly protective vaccine against meningococcus B has been a longstanding challenge in order to provide more comprehensive protection against the most common pathogenic meningococcus. Currently this is the predominant strain in Europe and is a substantial contributor to the disease burden in the United States, in large part due to the control of other strains with effective MebC or MenACWY vaccine strategies. In this context, adding a meningococcal B vaccine as a standalone or eventually combined vaccine can be foreseen for both regions in the near future.”
The researchers used whole-genome sequencing to identify proteins on the surface of many meningococcal strains and developed the broadly protective vaccines against serogroup B. This pivotal study showed a potentially protective immune response against serotype B in almost 100% of vaccinated adolescents (a total of 1631 adolescents with a mean age of nearly 14 years), irrespective of previous antibody status. The vaccine was also found to be well-tolerated.
Protective human complement titres (the lowest concentration of virus that still infects cells) against 3 meningococcal serogroup B strains developed in from 92% to 97% of adolescents after 1 dose of 4CMenB vaccine and only 29% to 50% following placebo administration. Protective titres increased to from 99% to 100% after 2 or 3 doses were administered at 1-, 2-, or 6-month intervals. The high percentage of participants in the study with preexisting human complement titres against meningococcal test strains indicates environmental exposure.
The authors note that the actual level of protection will depend on geographical strain variation, as circulating meningococcal B strains are known to vary worldwide. Nonetheless, data on invasive strains of the disease circulating in Chile would suggest that 2 doses of 4CMenB given to healthy adolescents are protective against meningococcal serogroup B disease. Additional studies also have shown the vaccine to be effective in adults and children.
In an accompanying editorial, David S. Stephens, from Emory University School of Medicine and the VA Medical Center, Atlanta, Georgia, questions whether additional booster doses would be needed to maintain protection, and whether the vaccine could be targeted to infants and young children — a major group at risk for serogroup B disease. “Data are also needed for concurrent administration of 4CMenB with other vaccines,” Dr. Stephens states, adding that answers to all of these questions “are crucial to widespread use and population-specific recommendations.”
Dr Myron Christodoulides, chair of Meningitis UK’s Scientific Medical Panel and expert in microbiology and infection at the University of Southampton, said “Previous studies have shown that 4CMenB has the potential to provide significant protection when administered to infants. This new study shows that the vaccine could also be highly protective in the adolescent age group. However, there are still a number of important questions to be answered such as how many strains it will protect against, how long the protection will last and whether it will stop the bacteria from being passed on to others, providing indirect protection to those not vaccinated.”
Steve Dayman, founder of Meningitis UK who lost his own son Spencer to the disease in 1982, said, “It is extremely encouraging that the vaccine could provide almost 100 per cent protection to adolescents. Behind the under-fives, teenagers are the next most at-risk from this disease. Meningitis can kill in hours and we have seen first-hand the devastation this disease can cause people. If introduced, this vaccine will be the first of its kind and could save thousands of lives but it is vital that research continues to develop improved vaccine strategies.”
The study was backed by Novartis. The findings follow successful studies of the vaccine in infants and adults. Infants and adolescents are most at risk of the potentially fatal and sometimes debilitating infections. Novartis has already asked European regulators for a green light to provide the vaccine to at-risk patients, and a nod to begin sales of the vaccine could come this spring. Pharmaceutical company, Pfizer is also in the process of developing a Meningitis B vaccine to protect teenagers.