Percent of 11-16 year-olds vaccinated with MCV4, for all 5 MCOs combined, 2005. MCV4 - Meningococcal conjugate vaccine; MCO - Managed care organization. i - Jan 14, 2005 - Food and Drug Administration (FDA) licenses MCV4. ii - Feb 10, 2005 - Advisory Committee on Immunization Practices (ACIP) recommends MCV4. iii - May 30, 2005 - ACIP recommendations published (become official). iv - July 19, 2005 - MCV4 manufacturer announces limits on MCV4 orders. v - Sep 30, 2005 - FDA and Centers for Disease Control and Prevention announce an investigation of a potential link between MCV4 and Guillain-Barré Syndrome.