All of the meningococcal vaccines are very safe.. Many million doses of the group C vaccine have been administered in England over the past 8 years without any serious side effects being noted. The group C vaccine has been used routinely for infants and adolescents throughout Canada without any serious reactions being reported. The new group A-C-Y-W135 conjugate vaccine (Menactra) has been administered to several million adolescents in the USA.