GBS and Menactra Meningococcal Vaccine

by CDC

The CDC and FDA, in partnership with state health departments, are investigating cases of Guillain-Barré syndrome (GBS) among adolescents who have recently received tetravalent (A, C, Y, W135) meningococcal conjugate vaccine (Meningococcal Polysaccharide Diphtheria Toxoid Conjugate Vaccine, Menactra, sanofi pasteur [MCV4]). As of September 22, 2006 the Vaccine Adverse Event Reporting System (VAERS) received 17 confirmed case reports of GBS in adolescents after receipt of MCV4 Menactra meningococcal vaccination. Fifteen people, 11 to 19 years of age, experienced symptoms within six weeks after receiving Menactra®. Two other reports of GBS among persons 20 years of age and older have alsobeen confirmed. The symptom onset was 2-33 days after vaccination. The timing and onset of neurological symptoms are reasons to gather further information.

While this study suggests a small increased risk of Guillain-Barré Syndrome (GBS) following Menactra immunization, there are a number of limitations in the data. The findings should be viewed with caution until they can be further studied and clarified. CDC is unable to determine if Menactra® increases the risk of GBS in persons who receive the vaccine at this time. GBS is a rare illness and the expected background population rates of GBS are not precisely known. An ongoing known risk for serious meningococcal disease exists.

CDC recommends that adolescents and their caregivers be informed of this ongoing investigation as part of the consent process for vaccination with MCV4.

Whether receipt of MCV4 vaccine might increase the risk for recurrence of GBS is unknown. Persons with a history of GBS who are not in a high risk group for invasive meningococcal disease should not receive MCV4.

FDA and CDC are requesting that providers or other persons with knowledge of possible cases of GBS (or other clinically significant adverse events) occurring after vaccination with MCV4 and/or other vaccines report them to VAERS.

CDC further requests that healthcare providers report other cases of GBS (even those not associated with MCV4 or other vaccination) that occur among persons 11-19 years of age to state health departments in accordance with state or local disease-reporting guidelines. Provisional case definitions for GBS have been developed to assist public health and other medical personnel with GBS surveillance activities.

Additional Facts

Invasive meningococcal disease

• Occurs in three common clinical forms: meningitis (49% of cases), blood infection (33%) and pneumonia (9%); other forms account for the remainder (9%) of the cases.
• Can have an abrupt onset with a rapid course of disease.
• Has a case fatality rate of 10%-14%; 11%-19% of survivors suffer serious sequelae including deafness, neurologic deficit, or limb loss.
• Affects approximately 1 in 100,000 people annually in the United States.
• Cases in the United States are almost all caused by caused by Neisseria meningitidis bacteria serogroups B, C and Y.

High risk groups for invasive meningococcal disease include

• college freshmen living in dormitories
• microbiologists who are routinely exposed to isolates of N. meningitidis
• military recruits
• persons who travel to or reside in countries in which N. meningitidis is hyperendemic or epidemic, particularly if contact with the local population will be prolonged
• persons who have terminal complement component deficiencies
• persons who have anatomic or functional asplenia

Meningococcal Vaccines

Two vaccines licensed in the United States protect against invasive meningococcal disease, tetravalent (A, C, Y, W135) meningococcal conjugate vaccine (MCV4) and tetravalent (A, C, Y, W135) Meningococcal Polysaccharide Vaccine (MPS4).There is currently no licensed vaccine that protects against serogroup B in the United States.

Since February 2005, CDC's Advisory Committee on Immunization Practices (ACIP) has recommended routine vaccination of adolescents 11-12 years of age with MCV4. For adolescents who have not previously received MCV4, ACIP also recommends vaccination before high-school entry (at approximately age 15 years) as an effective strategy to reduce meningococcal disease incidence among adolescents and young adults.

ACIP recommends routine vaccination with meningococcal vaccine (MCV4 preferred for persons 11-55 years of age, MPS4 acceptable) who are at high risk for meningococcal disease (see high risk groups above) and during meningococcal outbreaks caused by vaccine-preventable serogroups.

Approximately 5.7 million doses of MCV4 have been distributed nationally since March 2005 (sanofi pasteur, unpublished data, 2006). Although the number of doses distributed is known, the exact number of vaccine doses administered is unknown.

Guillain-Barré syndrome (GBS)

GBS is a serious neurologic disorder involving inflammatory demyelination of peripheral nerves. It can occur spontaneously or after certain events such as infections.

Illness is typically characterized by the subacute onset of progressive, symmetrical weakness in the legs and arms, with loss of reflexes. Sensory abnormalities, involvement of cranial nerves, and paralysis of respiratory muscles also can occur. A small proportion of patients die, and 20% of hospitalized patients can have prolonged disability.

Campylobacter jejuni, which causes bacterial gastroenteritis is one identified precipitating factor for GBS.

The precise rate of GBS in adolescents is unknown. Data from the Vaccine Safety Datalink (VSD), a collaborative project between CDC and eight managed care organizations in the United States, and the Health Care Utilization Project on GBS incidence in persons aged 11-19 years indicate a background annual incidence of 1-2 cases per 100,000 persons per year.

This finding suggests that the rate of GBS among MCV4 recipients based on the number of cases reported within 6 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 neurological symptoms (i.e., within 1.5-5 weeks of vaccination) is of concern.

About the Author

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The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.