Hajj, the pilgrimage to Mecca, Kingdom of Saudi Arabia (KSA), is one of the obligatory rituals of worship in Islam. Muslims with good health and sufficient financial status are required to visit Mecca at least once in their lifetime. Hajj is the largest, most diverse mass gathering of people in the world and attracts more than 2.5 million Muslims from more than 160 countries each year. Mecca is also the setting for a less critical ritual called Umrah, which can be done at any time during the year.1 Panobinostat purchase In the Netherlands, the Saudi

Arabia Embassy issues about 5,000 to 6,000 visas for Hajj every year (personal communication, April 17, 2010). Hajj lasts for 5 days, and it takes place from the 8th to the 12th day of the last month of the

Islamic calendar. As the Islamic calendar is lunar, the precise Gregorian calendar dates of the Hajj season vary each year.2 This continuous seasonal movement has implications for the spread of disease and other health risks.3 Transmission of infectious disease during mass gatherings has a global effect when visitors return to their country of origin. Individuals going on Hajj contributed to a global cholera outbreak in the 19th century.1 Several outbreaks of meningococcal serogroup A disease occurred during the 1987 Hajj season. For the following Hajj of 1988, the Saudi Arabian government required ALK inhibition compulsory why divalent AC vaccination to

issue a Hajj visa. During the Hajj seasons 2000–2002, there was a shift in the epidemic pattern of the meningococcal disease with a predominance of Neisseria meningitidis serogroup W135. In the year 2002, the Ministry of Health decided to demand the tetravalent ACYW135 polysaccharide vaccine. These interventions have quelled meningococcal disease since 2002.4 The travelers’ advice and vaccination clinic (TAVC) of the Public Health Service (PHS) Amsterdam, administers vaccinations including meningitis ACYW135 vaccine and provides about 25,000 travelers annually with individual recommendations for all their travels. Each year a large number of Muslims, in preparation for Hajj, visit the TAVC for the required tetravalent ACYW135 vaccine whereby they also receive standard recommendations. Although most travelers who visit the TAVC follow our advice, many Hajj pilgrims only take meningitis vaccination, and not the other recommended vaccinations. The aim of this study is to investigate the acceptance of non-required, but advised, vaccinations by the Mecca travelers who visit the PHS before departure for a mandatory vaccine. Further, we investigated predictors for this acceptance.