Contraindications and Precautions of Meningococcal Vaccine The main contraindication for meningococcal vaccines is A severe allergic reaction (eg, anaphylaxis) after previous dose or to a vaccine component The main precaution with meningococcal vaccines is Moderate or severe illness with or without a fever (vaccination is postponed until illness resolves if possible) Meningococcal conjugate vaccines may be given to pregnant women who are at increased risk of serogroups A, C, W, or Y meningococcal disease. Meningococcal serogroup B vaccines are recommended to be deferred during pregnancy unless women are at increased risk of serogroup B disease and the benefits of vaccination are thought to outweigh potential risks.