Unresoled Neisseria meningitidisinfection of history of meningococcal infection Unsuitable for antibiotic prophylaxis (e.g due to allergy) Known hypersensitivity to eculizumab, murine proteins or to any of the excipients Known or suspected hereditary complement deficiencies Women of child-bearing potential who are unwilling to use effective contraception during treatment and for 5 months after treatment is completed.