Seroepidemiological investigation of HAdV-4 infection among healthy adults in China and in Sierra Leone, West Africa

• DOI: 10.1038/s41426-018-0206-y
• Publication Date: 2018-12-03T07:48:36Z
• Authors: Busen Wang; Jianhua Li; Shipo Wu; Yi Chen; Zhe Zhang; Yanfang Zhai; Qiang Guo; Jinlong Zhang; Xiaohong Song; Zhenghao Zhao; Lihua Hou; Wei Chen
• Keywords: Adult; Male; 0301 basic medicine; China; Adolescent; Infectious and parasitic diseases; RC109-216; Antibodies, Viral; Microbiology; Article; Disease Outbreaks; Sierra Leone; Adenovirus Infections, Human; Young Adult; 03 medical and health sciences; Neutralization Tests; Seroepidemiologic Studies; Humans; Respiratory Tract Infections; Aged; Adenoviruses, Human; Middle Aged; Antibodies, Neutralizing; QR1-502; Healthy Volunteers; 3. Good health; Africa, Western; Female

An apparent increase in the frequency of human adenovirus type 4 (HAdV-4) infections among general populations has been observed over the past 10 years. However, available epidemiological data that may reflect previous viral circulation and assist in predicting potential outbreaks are sparse, particularly in mainland China and Africa. In this study, a convenient neutralization assay for use in the surveillance of historical HAdV-4 infections was established based on a recombinant luciferase-expressing virus. Subsequently, the neutralizing antibodies (nAbs) of 1013 healthy adult serum samples from China and Sierra Leone were evaluated. Our results showed that over 50% of the participants from China and nearly 70% of donors from Sierra Leone had detectable nAbs against HAdV-4 despite the few infection cases officially reported in these regions. Furthermore, the prevalence of nAbs to HAdV-4 is lower than that to HAdV-5, and both varied by geographic location. In addition, the seropositive rates of both HAdV-4 and HAdV-5 nAbs increased with age. However, the nAbs stimulated by HAdV-4 remained stable at low (≤200) levels among the different age groups, whereas moderate (201-1000) or high (>1000) nAb levels were produced by HAdV-5 and tended to decrease with age. These results elucidate the human humoral immune response against HAdV-4 and revealed that this virus may be an underestimated causative agent of respiratory disease among adults in China and West Africa, demonstrating the importance of HAdV-4 surveillance and providing useful insights for the future development of HAdV-4-based vaccines.