Respiratory Syncytial Virus (RSV)-Specific Antibodies in Pregnant Women and Subsequent Risk of RSV Hospitalization in Young Infants.

BACKGROUND: The fusion (F) glycoprotein of respiratory syncytial virus (RSV) represents the major neutralizing antigen, and antibodies against the pre-F conformation have the most potent neutralizing activity. This study aimed to assess the correlation between maternal antibody titers against the pre-F, post-F, and G glycoproteins and the child's risk of developing severe RSV bronchiolitis early in infancy. METHODS: We identified previously healthy term infants <3 months of age hospitalized with RSV bronchiolitis from December 2015 to March 2016. We measured IgG antibody titers to pre-F, post-F, and G proteins in maternal sera obtained at 9-12 weeks of pregnancy of these hospitalized infants' mothers (n = 94) and compared them with serum antibody titers of control pregnant mothers (n = 130) whose children were not hospitalized. RESULTS: All maternal samples (n = 224) had detectable pre-F antibodies. Pre-F antibody titers were significantly lower in mothers whose infants were hospitalized with RSV bronchiolitis compared with those mothers whose infants were not hospitalized (23.9 [range (or antibody titer range), 1.4-273.7] µg/L vs 30.6 [XXX, 3.4-220.0] µg/L; P = .0026). There were no significant differences in maternal post-F and G antibody titers between hospitalized and nonhospitalized infants. CONCLUSIONS: Our findings indicate that maternal pre-F antibodies are fundamental for providing immune protection to the infant.

Parental Socioeconomic Status and an Infant's Risk of Hospital Admission for RSV.

BACKGROUND: While clinical risk factors for RSV bronchiolitis are well established, data on socioeconomic risk factors is lacking. We explored the association of parental education, income, and employment status on an infant's risk of hospitalization for RSV bronchiolitis. METHODS: This population-based retrospective case-control study covered all RSV-related hospital admissions of under 1-year old children in Finland between 2004 and 2018. Controls were matched by month and year of birth, sex, province of residence, and family size. Registry data were linked using unique personal identity codes. Cases and controls were compared using adjusted odds-ratios (aOR) calculated for socioeconomic outcomes including maternal and paternal education, household income, and parental employment. RESULTS: A total of 10 767 infants and 50 054 controls were included in the study. Lower parental education significantly raised the risk for RSV hospital admission in infants, the risk growing with decreasing education levels; aOR 1.03 (0.96-1.09) with post-secondary education, 1.12 (1.05-1.2) with secondary education, and 1.33 (1.2-1.47) with primary education. Combined parental income was not significant: aOR 0.97 (CI 0.91-1.05), 1.02 (CI 0.95-1.1), 1(CI 0.92-1.08) and 0.94 (CI 0.85-1.04), respectively with decreasing income level. Unemployment of both parents seemed to be a risk factor for the child's RSV hospital admission, aOR 1.24 (1.12-1.38). CONCLUSIONS: Lower parental socioeconomic status may increase the risk of an infant's RSV hospitalization. Socioeconomic risk factors should be considered when designing RSV infection primary prevention strategies.

Immunity against vaccine-preventable diseases in Finnish pediatric healthcare workers in 2015.

Healthcare workers (HCWs) pose a risk to themselves and their patients if not protected against vaccine-preventable diseases. Alarmingly, lacking immunity has been reported in several studies. We assessed the immunity against vaccine-preventable diseases in 157 pediatric HCWs in Helsinki Children's Hospital. The HCWs enrolled answered a questionnaire and gave a serum sample. Antibodies were measured with EIA against MMR-diseases, tetanus and diphtheria toxins, Hepatitis B (HBV), Hepatitis A (HAV), varicella zoster and pertussis toxin. Neutralizing antibodies against poliovirus 1, 2 and 3 were measured. All of the HCWs had antibodies against tetanus and 89.8% against diphtheria. All had measurable levels of polio antibodies to all three polioviruses. 41% had suboptimal levels of antibodies against at least one of the antigens tested: MMR-viruses, diphtheria, HBV or polio. Measles, mumps and rubella antibodies were detectable in 81.5%, 89.2% and 93%, respectively. Only one HCW had no varicella-antibodies. Hepatitis B surface antibodies (HBsAb) were detected in 89.8% of the nurses. 67.5% had HAV-antibodies. A poor correlation between detected antibody levels and reported vaccination history was noticed, indicating a need for a universal record system for registering the vaccines given to each individual.