The potential for pneumococcal vaccination in Hajj pilgrims: expert opinion.

Hajj is the annual pilgrimage to Mecca in the Kingdom of Saudi Arabia, and is one of the largest mass gathering events in the world. Acute respiratory tract infections are very common during Hajj, primarily as a result of close contact among pilgrims, intense congestion, shared accommodation and air pollution. A number of vaccines are (or have been) recommended for Hajj pilgrims in recent years. Several additional vaccines could significantly reduce the morbidity and mortality at Hajj and should be considered in health recommendations for pilgrims. Pneumococcal vaccines (particularly for those aged >65 years) are widely available, and have been shown to reduce the burden of disease associated with Streptococcus pneumoniae infection. Importantly, a considerable percentage of Hajj pilgrims have pre-existing illnesses or are elderly, both important risk factors for pneumococcal infection. While there are substantial gaps that need to be addressed regarding our knowledge of the exact burden of disease in Hajj pilgrims and the effectiveness of pneumococcal vaccination in this population, S. pneumoniae may be an important cause of illness among this group of travelers. It can be assumed that the majority of pneumococcal serotypes circulating during Hajj are included in the existing pneumococcal vaccines.