ABSTRACT
Here we report horizontal symptomatic transmission of the Leningrad-Zagreb (L-Zagreb) mumps vaccine virus. Children who were the source of transmission had been vaccinated with the MMR vaccine (Serum Institute of India) contained L-Zagreb mumps virus. This is the first report of horizontal symptomatic transmission of this vaccine. The etiology of all seven contact cases was confirmed by epidemiological linking, serology and by F, SH, NP and HN mumps virus genes sequencing.
Subject(s)
Meningitis, Viral/transmission , Mumps Vaccine/adverse effects , Mumps/transmission , Adult , Child, Preschool , Female , Humans , Male , Meningitis, Viral/diagnosis , Meningitis, Viral/drug therapy , Mumps/diagnosis , Mumps/drug therapy , Mumps Vaccine/genetics , Mumps Vaccine/immunology , Treatment OutcomeABSTRACT
The purpose of this study was to investigate mumps vaccine failures (VF) in a highly vaccinated population of Minsk, Belarus, and to investigate a possible role for virus strain-specific immunity. During our 3-year study period, 22 adults were admitted to the Infectious Diseases Hospital in Minsk with a diagnosis of mumps. A genotype H1 mumps virus (MuV) strain was identified in all patients. Of 15 patients from whom the paired sera were collected, 9 were confirmed to have been previously vaccinated. Serological examinations indicated primary VF in seven of these cases and secondary VF in two. Despite almost all vaccinated patients possessing MuV specific IgG, few possessed neutralizing antibody to the vaccine strain and titers were nominal. Importantly, none of the sera were able to neutralize a genotype H MuV strain. Our results demonstrate the importance of assaying for neutralizing antibody and support the assertion that antigenic differences between wild type and vaccine MuV strains may play a role in cases of breakthrough infection in vaccinees.
