Measles humoral and cell-mediated immunity in children aged 5-10 years after primary measles immunization administered at 6 or 9 months of age.

Background: Given the high infant measles mortality rate, there is interest in whether a measles immunization regimen beginning at <12 months of age provides lasting immunity.

Methods: Measles-specific immune responses were evaluated in 70 children aged 5-10 years after primary measles vaccine administered at 6, 9, or 12 months.

Results: At 5-10 years of age, the stimulation index for measles T-cell proliferation was 11.

Age-related increase in the frequency of CD4(+) T cells that produce interferon-gamma in response to staphylococcal enterotoxin B during childhood.

Background: The susceptibility of infants to infections is well defined clinically, and immunologic abnormalities have been described. Immune maturation is complex, however, and the interval during which changes occur during childhood has not been identified.

Methods: To assess age-related differences in the CD4(+) T cell responses, we evaluated the frequency of CD4(+) T cells that produced interferon (IFN) gamma in response to staphylococcal enterotoxin B (SEB) stimulation in 382 healthy infants and children (2 months to 11 years of age) and 66 adults.

Effects of interleukin-12 and interleukin-15 on measles-specific T-cell responses in vaccinated infants.

Understanding the infant host response to measles vaccination is important because of their increased mortality from measles and the need to provide effective protection during the first year of life. Measles-specific T and B-cell responses are lower in infants after measles vaccination than in adults. To define potential mechanisms, we investigated age-related differences in measles-specific T-cell proliferation, CD40-L expression, and IFN-gamma production after measles immunization, and the effects of rhIL-12 and rhIL-15 on these responses.

T cell immunity to measles viral proteins in infants and adults after measles immunization.

Vaccination of infants against measles remains of global importance, and proposed new vaccine strategies include the use of measles proteins or synthetic peptides as immunogens. We studied cell-mediated immunity to whole measles antigen and measles proteins in immune adults and infants after measles vaccine. Further, we measured CD8+ T cell responses to peptide pools corresponding to the nucelocapsid (N) measles protein in adults given measles vaccine.

Humoral and cell-mediated immune responses to an early 2-dose measles vaccination regimen in the United States.

Background: Shifts in peak measles incidence to children <12 months old and the associated high mortality support the study of an early 2-dose measles vaccine regimen.

Methods: Fifty-five infants were vaccinated with measles vaccine at age 6 (n=32) or 9 (n=23) months, followed by measles-mumps-rubella (MMR)-II vaccine at age 12 months. A control group received MMR-II only at age 12 months.

Measles and mumps vaccination as a model to investigate the developing immune system: passive and active immunity during the first year of life.

Evaluations of neutralizing antibody responses in 6-, 9- and 12-month-old infants given measles or mumps vaccine indicated that 6-month-old infants had diminished humoral immune responses associated with passive antibody effects, but also had an intrinsic deficiency in antiviral antibody production, which was independent of passive antibody effects. In contrast, lower neutralizing antibody titers in 9-month-olds were related only to passive antibody effects. Measles and mumps-specific T-cell proliferation and interferon-gamma (IFNgamma) production were induced by vaccination at 6, 9 or 12 months, regardless of passive neutralizing antibodies or age.