Seroprevalence of human adenovirus type 5 neutralizing antibodies in the Philippines

• Published in: PloS one Vol. 18; no. 12; p. e0293046
• Main Authors: Francisco, Abialbon G, Reyes, John Carlo B, Tabios, Ian Kim B, Cruz, Criselda Jean G, Ang, Mark Angelo C, Heralde, Francisco M, Lacuna, Azita Racquel G, de Paz-Silava, Sheriah Laine M
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 01.12.2023; Public Library of Science (PLoS)
• Subjects: Adenoviruses; Antibodies; Blood & organ donations; Clinical trials; Coronaviruses; COVID-19 vaccines; Cytomegalovirus; Disease transmission; Effectiveness; Genetic vectors; Genomes; Immunity; Immunogenicity; Laboratories; Luciferase; Medical research; Medicine, Experimental; Military bases; Neutralization; Neutralizing; Patient outcomes; Plasma; Population; Rural areas; Sample size; Serology; Statistics; Vaccination; Vaccine efficacy; Vaccines; Viral antibodies; Viral vaccines; Virus research; Viruses; Philippines; China; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0293046

Human adenovirus (HAdV), particularly the HAdV type 5 (HAdV-5), has been extensively utilized in the development of vector vaccines due to its high immunogenicity, good safety profile, and ease of propagation. However, one of the main challenges in its use is the presence of pre-existing immunity among vaccine recipients. Pre-existing neutralizing antibodies (NAbs) can prevent the uptake of HAdV-5 vectors and reduce vaccine efficacy. Hence, this study investigated the seroprevalence of NAbs against HAdV-5 in urban and rural regions of the Philippines. Luciferase-based neutralization assay was performed on 391 plasma/serum samples. Out of these samples, 346 or 88.5% were positive for HAdV-5 NAbs, and the majority of them (56.8%) had high titers against the virus. Among the regions included in this study, Bicol (Region V) had the highest seroprevalence rate (94.1%). Our findings show that a significant number of adults in the Philippines have pre-existing immunity against HAdV-5. This supports the recommendation that vaccination programs in the country should consider implementing vaccination techniques, such as a prime-boost regimen or addition of booster doses, to address the potential negative effects of pre-existing HAdV-5 immunity in the efficacy of adenoviral vector-based vaccines.