Neutralizing antibodies against adenovirus type 2 in normal and HIV-1-infected subjects: Implications for use of Ad2 vectors in vaccines

ABSTRACTPre-existing neutralizing antibodies (NAbs) directed against vaccine vectors have attracted considerable research attention. Therefore, our aim was to establish a high-throughput economical neutralization assay to investigate the epidemiology of adenovirus type 2 (Ad2)-specific immunity in China and developed countries, including in a Chinese Human immunodeficiency virus (HIV)-1-infected population, and to guide the application of Ad2-vectored vaccines. We established a FluoroSpot-based anti-Ad2-virus neutralization assay using a recombinant replication-deficient Ad2 that expresses enhanced green fluorescent protein and standardized the critical parameters, including the choice of cell line, cell concentration, viral infective dose, and incubation time. The sera of 561 healthy individuals from China and developed countries and from 230 HIV-1-infected Chinese individuals were screened with this assay for Nabs against Ad2. The prevalence of anti-Ad2 NAbs was high in both China (92.2%) and developed ...