Incidence and Prevention of Invasive Meningococcal Disease in Global Mass Gathering Events.

INTRODUCTION: Mass gathering events involve close contact among large numbers of people in a specific location at the same time, an environment conducive to transmission of respiratory tract illnesses including invasive meningococcal disease (IMD). This report describes IMD incidence at mass gatherings over the past 10 years and discusses strategies to prevent IMD at such events. METHODS: A PubMed search was conducted in December 2018 using a search string intended to identify articles describing IMD at mass gatherings, including religious pilgrimages, sports events, jamborees, and refugee camps. The search was limited to articles in English published from 2008 to 2018. Articles were included if they described IMD incidence at a mass gathering event. RESULTS: A total of 127 articles were retrieved, of which 7 reported on IMD incidence at mass gatherings in the past 10 years. Specifically, in Saudi Arabia between 2002 and 2011, IMD occurred in 16 Hajj pilgrims and 1 Umrah pilgrim; serotypes involved were not reported. At a youth sports festival in Spain in 2008, 1 case of serogroup B IMD was reported among 1500 attendees. At the 2015 World Scout Jamboree in Japan, an outbreak of serogroup W IMD was identified in five scouts and one parent. At a refugee camp in Turkey, one case of serogroup B IMD was reported in a Syrian girl; four cases of serogroup X IMD occurred in an Italian refugee camp among refugees from Africa and Bangladesh. In 2017, a funeral in Liberia resulted in 13 identified cases of serogroup C IMD. Requiring meningococcal vaccination for mass gathering attendees and vaccinating refugees might have prevented these IMD cases. CONCLUSIONS: Mass gathering events increase IMD risk among attendees and their close contacts. Vaccines preventing IMD caused by serogroups ACWY and B are available and should be recommended for mass gathering attendees. FUNDING: Pfizer.

Meningococcal Group A, C, W, and Y Tetanus Toxoid Conjugate Vaccine: A Review of Clinical Data in Adolescents.

MenACWY-TT (Nimenrix) is a quadrivalent meningococcal vaccine containing polysaccharides from serogroups A, C, W, and Y conjugated to a tetanus toxoid carrier protein. MenACWY-TT is licensed in some countries as a three-dose primary series in individuals as young as 6 weeks of age and as a single dose in individuals ≥12 months of age. MenACWY-TT use is supported by long-term immunogenicity and safety across age groups, including data from several phase 2, 3, and 4 clinical studies in adolescents and young adults. Adolescents are an important population in the epidemiology, transmission, and prevention of invasive meningococcal disease, with this age-based population having the highest risk for carriage and transmission as well as one of the highest risks of disease. This age group is emerging as a target population in meningococcal vaccination programs globally, as vaccinating adolescents and young adults could potentially not only decrease disease rates directly for those vaccinated but also indirectly for unvaccinated individuals by decreasing carriage and eliciting herd protection. This review will consider available data for MenACWY-TT in adolescents, including safety and immunogenicity, booster and memory responses, persistence, and coadministration with other vaccines, with an emphasis on the rationale for use of MenACWY-TT and other quadrivalent meningococcal vaccines in adolescents to address the changing epidemiology of meningococcal disease.

A Review of Meningococcal Disease and Vaccination Recommendations for Travelers.

International travel has been steadily increasing since the middle of the twentieth century, including travel to regions with high levels of endemic meningococcal disease and areas with sporadic or sustained meningococcal outbreaks. Although invasive meningococcal disease (IMD) is relatively rare in travelers since the advent of quadrivalent meningococcal vaccines, it remains a serious concern because of its rapid progression, poor prognosis and outcomes, associated treatment delays, and the potential to precipitate outbreaks. Moreover, fatality occurs in up to 22% of those infected. This review will focus on IMD in travelers, with an emphasis on IMD epidemiology and the geographic regions of potential concern for international travelers. As vaccination is the best approach for preventing IMD among travelers, currently available meningococcal vaccines and corresponding country-specific national meningococcal vaccination recommendations, where available, will be summarized by age and type of vaccine recommended. The use of the quadrivalent meningococcal vaccines, specifically the tetanus toxoid conjugate vaccine (including MenACWY-TT; Nimenrix®), as a protective measure against IMD in travelers will be emphasized. FUNDING: Pfizer Inc.