A serological survey of human adenovirus serotype 2 and 5 circulating pediatric populations in Changchun, China, 2011

Abstract

BackgroundEfficacy of recombinant adenovirus serotype 5 (rAd5) vaccine vectors for human immunodeficiency virus type 1 (HIV-1) and other pathogens have been shown to be limited by high titers of pre-existing Ad5 neutralizing antibodies (NAbs) in the developing world.ResultsUsing a secreted embryonic alkaline phosphatase (SEAP) neutralization assay, 50% serum neutralization titers against rAd2 and rAd5 vectors were measured in samples from 274 infants and young children in northeast China. The pediatric population was found to be 59.6% and 43.3% seropositive for rAd2 and rAd5, respectively. Of all participants, 44.9% had moderate and high (> 200) and 25.6% had high (>1000) Ad2 NAb titers, compared with the corresponding rates of 26.6% and 9.3% against Ad5. Marked age-dependent increases in NAb titers to both Ad serotypes were observed across five age groups, with the exception of infants in the 0-6-month group commonly having relatively high titers due to pre-existing maternal antibodies.ConclusionsOur data suggest that Ad-based therapies may be suitible for children in the 7-12-month age range in this region.

Development of an Adenovirus-Based Respiratory Syncytial Virus Vaccine: Preclinical Evaluation of Efficacy, Immunogenicity, and Enhanced Disease in a Cotton Rat Model

“…Nevertheless, a potential target population for an Ad5-vectored RSV vaccine still exists among infants 4 to 23 months old who present with limited adenoviral preformed active immunity (since Ad5 infections are uncommon early in life) and who have little or no passive immunity (since infants in this age group have already lost most or all of the anti-Ad5 antibodies acquired from their mothers) (17,18). The seroprevalence of human adenovirus serotypes 2 and 5 circulating in different age groups supports the knowledge that antiadenoviral neutralizing immunity is present in newborns and tends to decline after 6 months of age (19). Thus, recombinant adenovirus may represent an excellent platform for vaccines against RSV and other members of the paramyxoviridae (human parainfluenza virus type 1 [hPIV1] to hPIV4, metapneumovirus) within this young pediatric population.…”

Prevalence of serum neutralizing antibodies to adenovirus type 5 (Ad5) and 41 (Ad41) in children is associated with age and sanitary conditions

“…Moderate prevalence of low level Ad NAb in infants less than 6 months of age was commonly detected in prior reports [22,28,33,34], which was attributed to maternal antibodies. Because of the very limited sample size for the group of <6 months of age, it was combined to neighboring groups and was not separately analyzed in this study.…”

Adenoviral Vector Vaccines Antigen Transgene

“…Infants aged 6-12 months tend to have low titers, which then steadily increase. 40 A study conducted in India showed that neutralizing antibodies to HAdV-5 virus are slightly higher in infants aged 1-6 months than aged 7-12 months. Titers then steadily increase until adulthood.…”