title: Cross-neutralization between three mumps viruses & mapping of haemagglutinin-neuraminidase (HN) epitopes.
abstract: OBJECTIVE
  The reports from the countries where mumps vaccine is given as routine immunization suggest differences in mumps virus neutralizing antibody titres when tested with vaccine and wild type viruses. Such reports are unavailable from countries like India where mumps vaccine is not included in routine immunization. We, therefore, undertook this study to understand the cross-neutralization activity of Indian mumps viruses.
  
  
  METHODS
  By using commercial mumps IgG enzyme immunoassay (EIA) and a rapid focus reduction neutralization test (FRNT), a panel of serum samples was tested. The panel consisted of 14 acute and 14 convalescent serum samples collected during a mumps outbreak and 18 archived serum samples. Two wild types (genotypes C and G) and Leningrad-Zagreb vaccine strain (genotype N) were used for the challenge experiments and FRNT titres were determined and further compared. The HN protein sequence of three mumps viruses was analyzed for the presence of key epitopes.
  
  
  RESULTS
  All serum samples effectively neutralized mumps virus wild types and a vaccine strain. However, significantly lower FRNT titres were noted to wild types than to vaccine strain (P<0.05). The comparison between EIA and FRNT results revealed 95.6 per cent agreement. No amino acid changes were seen in the epitopes in the Indian wild type strains. All potential N-linked glycosylation sites were observed in Indian strains.
  
  
  CONCLUSIONS
  Good cross-neutralization activity was observed for three mumps virus strains, however, higher level of FRNT titres was detected for mumps virus vaccine strain compared to Indian wild type isolates.
authors.affiliation: WHO National Measles Reference Laboratory, National Institute of Virology (ICMR), Pune, India.
authors.forename: Sunil R
authors.initials: SR
authors.lastname: Vaidya
authors.forename: Garima M
authors.initials: GM
authors.lastname: Dvivedi
authors.forename: Santoshkumar M
authors.initials: SM
authors.lastname: Jadhav
mesh_terms: D057134:Antibodies, Neutralizing / Q000276:immunology / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D000939:Epitopes / Q000276:immunology / Q000627:therapeutic use; D005838:Genotype; D015707:HN Protein / Q000276:immunology* / Q000627:therapeutic use; D006801:Humans; D007194:India; D009107:Mumps / Q000276:immunology / Q000517:prevention & control*; D009108:Mumps Vaccine / Q000276:immunology / Q000627:therapeutic use*; D009109:Mumps virus / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity; D009500:Neutralization Tests
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D015707:HN Protein; D009108:Mumps Vaccine