New Guidelines Recommend Revaccinating Those at Prolonged Increased Risk for Meningococcal Disease

From Medscape Medical News
Laurie Barclay, MD

September 25, 2009 — The Advisory Committee on Immunization Practices (ACIP) has updated and replaced its previous recommendations for revaccinating persons at prolonged increased risk for meningococcal disease. The new guidelines, which were approved at the June 24, 2009, ACIP meeting, are published in the September 25 issue of the Morbidity and Mortality Weekly Report.

ACIP has previously recommended quadrivalent meningococcal conjugate vaccine (MCV4; Menactra, Sanofi Pasteur) for all persons aged 11 to 18 years, as well as for persons aged 2 to 55 years who are at increased risk for meningococcal disease. Although MCV4 is licensed as a single dose, ACIP now recommends that persons at increased risk for meningococcal disease for prolonged periods of time because of medical conditions or because of prolonged exposure should be revaccinated with MCV4 every 5 years.

"Because of the high risk for meningococcal disease among certain groups and limited data on duration of protection, at its June 2009 meeting ACIP recommended that persons previously vaccinated with either MCV4 or MPSV4 (Menomune, Sanofi Pasteur) who are at prolonged increased risk for meningococcal disease should be revaccinated with MCV4," writes ACIP's Meningococcal Vaccine Work Group. "Persons who previously were vaccinated at age ≥7 years and are at prolonged increased risk should be revaccinated 5 years after their previous meningococcal vaccine, and persons who previously were vaccinated at ages 2–6 years and are at prolonged increased risk should be revaccinated 3 years after their previous meningococcal vaccine.... Persons who remain in one of these increased risk groups indefinitely should continue to be revaccinated at 5-year intervals."

Conditions placing persons at prolonged increased risk for meningococcal disease include persistent complement component deficiencies (such as C3, properdin, Factor D, and late complement component deficiencies), anatomic or functional asplenia, and prolonged exposure (eg, microbiologists routinely working with Neisseria meningitidis, or travelers to or residents of countries where meningococcal disease is hyperendemic or epidemic).

At this time, it is not recommended that college freshmen who live in dormitories but who were previously vaccinated with MCV4 be revaccinated. However, college freshmen who live in dormitories and who were vaccinated with MPSV4 5 or more years previously should be vaccinated with MCV4.

The new recommendations from ACIP's Meningococcal Vaccine Work Group are based on a review of data on the risk for meningococcal disease, decrease in antibody titer, and the safety and immunogenicity of revaccination with MCV4 at 3 and 5 years after the first dose of MCV4 or MPSV4.

Higher levels of serum bactericidal antibody against N meningitidis can offer increased protection to persons with prolonged increased risk for meningococcal disease. All persons revaccinated with MCV4 in the reviewed studies reached serum bactericidal antibody titers greater than 1:128 for serogroups C and Y. About 50% to 70% of persons in previously vaccinated and in unvaccinated groups reported mild to moderate local and systemic adverse events after revaccination or initial vaccination with MCV4, but no serious adverse events were reported in either group.

"On the basis of these data, expert opinion of the workgroup members, and feedback from partner organizations, the workgroup proposed that persons at prolonged increased risk for meningococcal disease be revaccinated with MCV4," the ACIP Meningococcal Vaccine Work Group writes. "Although the duration of protection from MCV4 is unknown, most entering college students will have received MCV4 within the preceding 4 years. Because of the limited period of increased risk, ACIP currently does not recommend that college freshmen living in dormitories who were previously vaccinated with MCV4 be revaccinated."

Information regarding MCV4 and other recommendations for individuals aged 2 to 55 years has been published previously. This includes a routine recommendation that persons aged 11 to 18 years be vaccinated with MCV4.

Morb Mortal Wkly Rep. 2009:58;1042–1043.