BACKGROUND: Few data are available on the risk of aseptic meningitis following vaccination with the Leningrad-Zagreb (L-Z) strain of mumps vaccine. In 1997 the mumps vaccine was introduced into the state of Rio Grande do Sul in Brazil through mass vaccination with mumps-measles-rubella (MMR), targeting children aged 1-11 years. Five municipalities used exclusively MMR vaccine containing the L-Z strain of mumps. An outbreak of aseptic meningitis was observed shortly after the mass campaign. METHODS: To estimate the risk of aseptic meningitis associated with this strain, we analysed vaccination and meningitis case surveillance data from the selected municipalities. A case of vaccine-associated aseptic meningitis was defined as one with a pleocytosis of 10-1,500 leukocytes/ml and occurring within 15-35 days after vaccine receipt. RESULTS: We estimated a risk of 2.9 cases per 10,000 doses of L-Z administered, equivalent to 1 case per 3,390 doses administered. The overall risk of aseptic meningitis following the campaign was increased 12.2-fold (95% CI: 6.0-24.7) compared with the same period in 1995-1996. Following the mass campaign, the incidence of mumps declined 93% during 1998-2000. CONCLUSIONS: Vaccination with the L-Z strain of mumps vaccine as part of a mass campaign was associated with a significantly increased risk of aseptic meningitis. Decisions about type of mumps vaccine and mumps vaccination strategies must consider vaccine safety issues in addition to other criteria.
BACKGROUND: Few data are available on the risk of aseptic meningitis following vaccination with the Leningrad-Zagreb (L-Z) strain of mumps vaccine. In 1997 the mumps vaccine was introduced into the state of Rio Grande do Sul in Brazil through mass vaccination with mumps-measles-rubella (MMR), targeting children aged 1-11 years. Five municipalities used exclusively MMR vaccine containing the L-Z strain of mumps. An outbreak of aseptic meningitis was observed shortly after the mass campaign. METHODS: To estimate the risk of aseptic meningitis associated with this strain, we analysed vaccination and meningitis case surveillance data from the selected municipalities. A case of vaccine-associated aseptic meningitis was defined as one with a pleocytosis of 10-1,500 leukocytes/ml and occurring within 15-35 days after vaccine receipt. RESULTS: We estimated a risk of 2.9 cases per 10,000 doses of L-Z administered, equivalent to 1 case per 3,390 doses administered. The overall risk of aseptic meningitis following the campaign was increased 12.2-fold (95% CI: 6.0-24.7) compared with the same period in 1995-1996. Following the mass campaign, the incidence of mumps declined 93% during 1998-2000. CONCLUSIONS: Vaccination with the L-Z strain of mumps vaccine as part of a mass campaign was associated with a significantly increased risk of aseptic meningitis. Decisions about type of mumps vaccine and mumps vaccination strategies must consider vaccine safety issues in addition to other criteria.
Authors: Silvia Perez-Vilar; Daniel Weibel; Miriam Sturkenboom; Steven Black; Christine Maure; Jose Luis Castro; Pamela Bravo-Alcántara; Caitlin N Dodd; Silvana A Romio; Maria de Ridder; Swabra Nakato; Helvert Felipe Molina-León; Varalakshmi Elango; Patrick L F Zuber Journal: Vaccine Date: 2017-05-27 Impact factor: 3.641
Authors: Eliane Matos dos Santos; Gloria Regina da Silva e Sá; Marilda Mendonça Siqueira; Reinaldo de Menezes Martins; Luiz Antonio Bastos Camacho; Vanessa dos Reis von Doellinger; Maria de Lourdes de Sousa Maia Journal: Mem Inst Oswaldo Cruz Date: 2014-05-07 Impact factor: 2.743