# Epidemiological characteristics and genomic analysis of respiratory adenovirus in Lanzhou City from 2023 to 2025

## TL;DR

This study analyzed respiratory adenovirus in Lanzhou City from 2023 to 2025, finding high prevalence in children and seasonal patterns, with HAdV-B3 as the dominant strain.

## Contribution

The study identifies HAdV-B3 as the prevalent strain in Lanzhou and suggests potential vaccine protection based on genetic similarity to a Guangzhou strain.

## Key findings

- HAdV positivity rate was 7.88% in respiratory specimens, higher in children and during autumn/winter.
- HAdV-B3 was the predominant strain, showing high genetic similarity to a Guangzhou vaccine candidate.
- Penton base RGD domain and Hexon antigenic epitope remained conserved in Lanzhou strains.

## Abstract

Human adenoviruses (HAdVs) are common pathogens causing inflammation in the upper respiratory tract, lungs, conjunctiva, urinary tract, and gastrointestinal tract. They can lead to severe, even fatal infections in immunocompromised patients, representing a significant public health threat. To comprehensively assess the impact of HAdV on public health, this study investigated the epidemiological and genetic characteristics of respiratory adenoviruses in Lanzhou City from 2023 to 2025.

From 2023 to 2025, 1,269 acute respiratory infection specimens were collected from sentinel hospitals in Lanzhou City. HAdV nucleic acids were detected using real-time fluorescent quantitative PCR (qPCR). A portion of HAdV-positive specimens underwent viral isolation using Hep-2 cells. Successfully isolated adenovirus strains were subjected to whole-genome sequencing. Phylogenetic trees were constructed for the HAdV whole genome, Penton base, Hexon, and Fiber genes, and protein variant sites were analyzed.

The overall HAdV positivity rate in acute respiratory infection specimens from Lanzhou City was 7.88% (100/1269) from 2023-2025, with a higher positivity rate observed in children aged ≤15 years. HAdV prevalence displayed seasonal variations, with significantly higher positivity rates in autumn and winter (10.83%, 73/674) compared to spring and summer (4.54%, 27/595). Whole-genome sequencing identified the predominant circulating HAdV strain in Lanzhou City during the study period as HAdV-B, all of which were HAdV-3. Phylogenetic analyses of the Penton base, Hexon, and Fiber genes revealed high genetic homology between all nine Lanzhou HAdV-B strains and the Guangzhou candidate vaccine strain (GenBank: DQ099432.4), clustering on the same branch. Furthermore, the Penton base RGD domain and Hexon antigenic epitope of the nine Lanzhou HAdV-B strains remained highly conserved compared to the Guangzhou candidate vaccine strain, showing no significant mutations.

The prevalent HAdV strain in Lanzhou City from 2023 to 2025 was type B3. Based on these findings, it is tentatively suggested that the vaccine candidate strain from Guangzhou may provide good immune protection against these prevalent strains, though verification through clinical trials is required.