Portal de Periódicos da CAPES

Measles Antibody Levels in Young Infants

2019; American Academy of Pediatrics; Volume: 144; Issue: 6 Linguagem: Inglês

10.1542/peds.2019-0630

1098-4275

Michelle Science, Rachel Savage, Alberto Severini, Elizabeth McLachlan, Stephanie L. Hughes, Callum Arnold, Susan E. Richardson, Natasha S. Crowcroft, Shelley L. Deeks, Scott A. Halperin, Kevin A. Brown, Todd F. Hatchette, Jonathan B. Gubbay, Tony Mazzulli, Shelly Bolotin,

Syphilis Diagnosis and Treatment

Infants are often assumed to be immune to measles through maternal antibodies transferred during pregnancy and, in many countries, receive their first measles-containing vaccine at 12 to 15 months. Immunity may wane before this time in measles-eliminated settings, placing infants at risk for measles and complications. We investigated humoral immunity to measles in infants <12 months of age in Ontario, Canada.We selected sera collected at a tertiary pediatric hospital from infants <12 months who were born at ≥37 weeks' gestational age. We excluded infants with conditions that affect antibody levels. We selected ≤25 sera from 8 predetermined age bands and tested them for measles-neutralizing antibody using the plaque-reduction neutralization test. We calculated the proportion immune at each age band, and predictors of infant susceptibility were assessed by using multivariable logistic regression and Poisson regression.Of 196 infant sera, 56% (110 of 196) were from boys, and 35% (69 of 196) were from infants with underlying medical conditions. In the first month, 20% (5 of 25) of infants had antibodies below the protective threshold, which increased to 92% (22 of 24) by 3 months. By 6 months, all infants had titers below the protective threshold. In a multivariable analysis, infant age was the strongest predictor of susceptibility (odds ratio = 2.13 for each additional month increase; 95% confidence interval: 1.52-2.97).Most infants were susceptible to measles by 3 months of age in this elimination setting. Our findings inform important policy discussions relating to the timing of the first dose of measles-containing vaccine and infant postexposure prophylaxis recommendations.