The Centers for Disease Control and Prevention (CDC) is recommending that caregivers of adolescents who receive quadrivalent meningococcal conjugate vaccine (MCV4; Menactra) be informed of an ongoing investigation into reports of Guillain-Barré syndrome in patients who received the vaccine. The CDC issued a dispatch on Oct. 6, 2005, which was published in the Oct. 14, 2005, issue of Morbidity and Mortality Weekly Report; it is available online athttp://www.cdc.gov/mmwr/preview/mmwrhtml/mm5440a6.htm.

In February 2005, the CDC’s Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination of adolescents at the preadolescent health care visit (at 11 to 12 years of age). For persons who have not been vaccinated previously, ACIP recommended vaccination before high-school entry (at approximately 15 years of age). Routine vaccination also was indicated for first-year college students living in dormitories and for other persons at increased risk.

As of October 4, 2005, the CDC’s Vaccine Adverse Event Reporting System (VAERS) received five reports of Guillain-Barré syndrome in persons after vaccination with MCV4. All reported cases occurred in persons 17 to 18 years of age who were vaccinated between June 10 and July 25, 2005. Symptom onset was 14 to 31 days after vaccination. The five affected patients were from Pennsylvania, New York, Ohio, and New Jersey.

Data suggest that the rate of Guillain-Barré syndrome reported within six weeks of administration of MCV4 is similar to what might have been expected to occur by chance alone. However, the timing of the onset of neurologic symptoms (i.e., within two to five weeks of vaccination) is of concern. In addition, the extent of under-reporting to VAERS is unknown; therefore, additional cases may be unreported.

To date, evidence is insufficient to conclude that MCV4 causes Guillain-Barré syndrome. An ongoing known risk for serious meningococcal disease exists. Therefore, the CDC is recommending continuation of current vaccination strategies. It is not known whether receipt of MCV4 may increase the risk for recurrence of Guillain-Barré syndrome; avoiding the vaccination of persons who are not at high risk for meningococcal disease and who are known to have had Guillain-Barré syndrome is prudent.

The CDC requests that physicians with knowledge of possible cases of Guillain-Barré syndrome or other clinically significant adverse events occurring after vaccination with MCV4 report these events to VAERS (http://www.vaers.hhs.gov; telephone, 800-822-7967). The CDC also requests that physicians report cases of Guillain-Barré syndrome in persons 11 to 19 years of age to state health departments. Cases of meningococcal disease should be reported to state health departments and, if available, information on vaccination status should be provided; isolates should be saved and sent to state health departments for serogroup identification.