(RNS) The nearly 3 million Muslims who will make next week’s annual hajj pilgrimage to the sacred Saudi Arabian city of Mecca are required to be vaccinated against meningitis. Swiss pharmaceutical giant Novartis claims to have developed, in 2010, the first anti-meningitis vaccine without pork, which Muslims are forbidden to consume under Islamic law. Many religious authorities have already certified the Menveo vaccine as “halal,” or permitted under Islamic law. Not all Muslims, however, believe the vaccine is truly halal. Anti-meningitis vaccine was developed in the 1930s, and pork derivatives were and remain an important part of the compound today.