Fig. 2.

General description of respiratory syncytial virus (RSV) infections in the child cohort during the follow-up. The study included 291 children from whom serum specimens were collected at aged 1, 2 and 3 years. Seropositivity is based on positive anti-RSV IgG antibody test results in whole RSV antigen enzyme immunoassay (EIA). Reinfection is determined as a significant (>25 EIA units) rise in serum anti-RSV IgG antibody levels between the yearly drawn serum specimens. The numbers in circles indicate the number of children and the percentages in parentheses indicate the percentage of children from the whole cohort (n = 291).