Preventing meningitis: New vaccine available

Meningococcal disease is a rare but potentially fatal bacterial infection that causes meningitis or sepsis in a majority of cases. Meningitis most frequently occurs in young children but sometimes can strike among adolescents and young adults living in close quarters, such as college students or military recruits. The most alarming feature of the disease is that it can progress very rapidly and kill an otherwise healthy individual in less than 48 hours.

Despite administration of appropriate antibiotics and adjunctive therapy, the mortality rate associated with meningococcal disease remains high, said Esther Hilburger, Pharm.D., clinical pharmacist at Sentara CarePlex Hospital in Hampton, Va. The licensure of Menactra vaccine, if it is coupled with widespread meningococcal immunization, represents a significant step toward eradicating this devastating disease, stated Michael Pichichero, M.D., professor of microbiology/immunology, pediatrics, and medicine, University of Rochester Medical Center.

In the United States, four meningococcal serogroups (C, Y, W-135, and B) are prevalent. Menactra vaccine contains three of these four serogroups, which are responsible for causing more than 75% of meningococcal diseases in adolescents.

The safety and immunogenicity of Menactra vaccine was demonstrated in clinical trials, which enrolled more than 7,500 adolescents and adults. All vaccine immunogenicity measurements indicated that a single dose of Menactra elicited strong immune responses, which were equivalent to a single dose of Menomune. The most common adverse events associated with Menactra vaccine were local pain and redness at the injection site, headache, and fatigue, said Hilburger. Most of these cases, however, were mild in intensity.

In order to accurately determine Menactra's length of protection, the FDA has asked the manufacturer to perform longer studies of the conjugate vaccine and conduct follow-up research tracking immunity levels five to 10 years after vaccination. Sanofi also plans to apply next month for approval to market Menactra for vaccination of two- to 10-year-olds and then eventually expand its indication to include adults over 55.

The Centers for Disease Control & Prevention's National Immunization Program (NIP) presented a cost-benefit analysis of Menactra to the Advisory Committee on Immunization Practices in October 2004. The proposed recommendations for the vaccine would be routine immunization of adolescents aged 11 to 12 years; catch-up vaccination of 12- to 19-year-olds; and immunization of persons at increased risk, such as college freshmen living in dorms. NIP's analysis predicted that the vaccination program would significantly reduce healthcare costs associated with preventable meningococcal diseases.