[A seroconversion study of the measles component of the MMR vaccine in adolescents of the town of Sabrosa].
The Portuguese national programme of vaccination has instituted a two-dose MMR vaccine schedule. The second dose of MMR (measles-mumps-rubella combined vaccine) is given at 11-13 years of age, for both sexes. This study was conducted to evaluate the duration of immunity of the monovalent measles vaccine, and the efficacy of a second dose given as MMR. MMR (Triviraten Berna with the strain Edmonston-Zagreb) was given to the 38 participants. Blood samples were collected before and after vaccination. Thirty-six participants had been vaccinated with measles monovalent vaccine during childhood. To measure anti-measles IgG (mIgG), an enzyme immunoassay was used. Participants were classified as "susceptible" or "immune", using 200 mIU/ml (milli international units per millilitre) as the threshold for "immune". Geometric mean concentration (GMC) of mIgG was 1401 mIU/ml in prevaccination sera (n = 38). Thirty-five (92%) of the adolescents were "immune". Only the two unvaccinated had a positive measles history. GMC in the sera of the 36 vaccinated participants was 1301 mIU/ml. Neither the time since measles vaccination nor age at vaccination were correlated with the levels of mIgG. After receiving MMR, all adolescents became "immune". GMC of mIgG was 2879 mIU/ml in postvaccination sera (n = 38). In 28 (74%) participants, mIgG levels increased after receiving MMR. Mean concentration increase was 1082 mIU/ml. For measles, results support the use of a two-dose MMR vaccine schedule in Portugal.
Gonçalves
G
G
Serviço de Higiene e Epidemiologia, Faculdade de Medicina, Universidade do Porto.
Tavares
F
F
de Andrade
H R
HR
D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D016014:Linear Models; D008457:Measles / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage* / Q000276:immunology*; D022542:Measles-Mumps-Rubella Vaccine; D009108:Mumps Vaccine / Q000008:administration & dosage*; D011174:Portugal; D012411:Rubella Vaccine / Q000008:administration & dosage*; D013997:Time Factors; D014505:Urban Population; D017778:Vaccines, Combined / Q000008:administration & dosage
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D008458:Measles Vaccine; D022542:Measles-Mumps-Rubella Vaccine; D009108:Mumps Vaccine; D012411:Rubella Vaccine; D017778:Vaccines, Combined