This Medical Product Alert relates to the circulation of confirmed falsified Mencevax ACWY in the WHO region of Africa Genuine Mencevax ACWY is used to prevent meningitis types A C W and Y On 15 March 2019 the Ministry of Public Health in Niger issued a call for vigilance regarding the circulation of falsified Mencevax ACWY vaccines This WHO medical product alert provides the details of those products which have been confirmed as falsified to date Inquiries indicate that the supply chain route of these falsified vaccines includes other countries in West Africa as such increased vigilance is requested in all countries of the region at all levels of the supply chain