Risk of respiratory syncytial virus infection for infants from low-income families in relationship to age, sex, ethnic group, and maternal antibody level

Respiratory syncytial virus infections during an epidemic period in Salvador, Brazil: viral antigenic group analysis and description of clinical and epidemiological aspects

“…In agreement with literature data (Parrot et al 1973, Glezen et al 1981, Weber et al 1998b, Loscertales et al 2002, RSV infections by both groups in Salvador were more frequent in children during their first year of life and mostly during the first six months. In our study, RSV infections in children younger than one month occurred in two hospitalized children with pneumonia, and both RSV belonged to group A.…”

Antibodies to Respiratory Syncytial Virus Polypeptides and their Significance in Human Infection

“…In interpreting these data it is important to appreciate that the 'protected group' must include an unknown proportion of babies susceptible to infection but who escaped exposure to RS virus during the trial period. Nevertheless, comparable results were reported by Glezen et al (1981) who showed that babies born to mothers with higher levels of neutralizing antibody for RS virus developed infection at a later age and had milder illness than infants receiving low or undetected levels of antibody.…”

Immune response to respiratory syncytial virus in young Brazilian children

“…There is a considerable amount of data about the humoral response to human RSV infection (3)(4)(5), but limited information about the cellular immune response (6)(7)(8). Studies on humans and animals have demonstrated that antibodies are important contributors to protective immunity (9)(10)(11)(12) and that cellular immunity is important for clearing the infection (13,14). The protective role of antibodies in human disease is probably best demonstrated by the correlation between higher levels of maternally acquired antibodies and less serious disease in infants (9,10) and the ability of high titered RSV intravenous immunoglobulin (Ig) to decrease the risk of serious disease when administered prophylactically (15).…”

“…Studies on humans and animals have demonstrated that antibodies are important contributors to protective immunity (9)(10)(11)(12) and that cellular immunity is important for clearing the infection (13,14). The protective role of antibodies in human disease is probably best demonstrated by the correlation between higher levels of maternally acquired antibodies and less serious disease in infants (9,10) and the ability of high titered RSV intravenous immunoglobulin (Ig) to decrease the risk of serious disease when administered prophylactically (15). The longer duration and severe complications of RSV infection in patients with reduced cellular immunity demonstrate the role of cellular immunity in clearing the infection (16,17).…”

“…The peak age for hospitalization associated with RSV infection occurs in infants less than 6 months of age (1,10), an age when maternally acquired antibodies are decreasing with a half life of about one month (18). The presence of these antibodies may not protect children against RSV infection (19,20) and may even contribute to the disease process, as hypothesized by some investigators (4,21).…”