Publications by authors named "Dayna Cheng"

Dengue virus (DENV) causes approximately 390 million dengue infections worldwide every year. There were 22,777 reported DENV infections in Tainan, Taiwan in 2015. In this study, we sequenced the C-prM-E genes from 45 DENV 2015 strains, and phylogenetic analysis based on C-prM-E genes revealed that all strains were classified as DENV serotype 2 Cosmopolitan genotype.

View Article and Find Full Text PDF

Enterovirus A71 (EV-A71) can induce severe neurological complications and even fatal encephalitis in children, and it has caused several large outbreaks in Taiwan since 1998. We previously generated VP1 codon-deoptimized (VP1-CD) reverse genetics (rg) EV-A71 viruses (rgEV-A71s) that harbor a high-fidelity (HF) 3D polymerase. These VP1-CD-HF rgEV-A71s showed lower replication kinetics and decreased virulence in an Institute of Cancer Research (ICR) mouse model of EV-A71 infection, while still retaining their antigenicity in comparison to the wild-type virus.

View Article and Find Full Text PDF

Enterovirus A71 (EV-A71) is a non-enveloped virus possessing 4 capsid proteins: VP1-VP4. The outermost capsid protein, VP1, plays roles in both antigenicity and virulence of the virus. The concept of generating other EV-A71 genotypes of reverse genetics (rg) viruses by replacing VP1 can be made possible with synthetic biotechnology, allowing us to redesign organisms, creating unavailable ones.

View Article and Find Full Text PDF

Broadly neutralizing ability is critical for developing the next-generation SARS-CoV-2 vaccine. We collected sera samples between December 2021-January 2022 from 113 Taiwan naïve participants after their second dose of homologous vaccine (AZD1222, mRNA-1273, BNT162-b2, and MVC-COV1901) and compared the differences in serological responses of various SARS-CoV-2 vaccines. Compared to AZD1222, the two mRNA vaccines could elicit a higher level of anti-S1-RBD binding antibodies with higher broadly neutralizing ability evaluated using pseudoviruses of various SARS-CoV-2 lineages.

View Article and Find Full Text PDF
Article Synopsis
  • * Genetic analysis revealed that the subgenotype B1 of CVA16 was the most common strain during the study period, while subgenotype B2 was only found in samples from the late 1990s.
  • * The study also identified significant genetic recombination between CVA16 and other virus strains, with findings indicating that the dominant subgenotype B1 shows potential as a candidate for developing a vaccine against CVA16.
View Article and Find Full Text PDF
Article Synopsis
  • RNA viruses, like DENV, have high mutation rates that lead to a diverse group of closely related viruses known as quasispecies, which may influence disease severity.
  • A study analyzed 22 DENV isolates (10 from mild cases and 12 from fatal cases) using Next Generation Sequencing, identifying six significant nucleotide variations linked to more severe outcomes.
  • Further testing of two specific viral variants showed increased replication rates in certain cell types and revealed temperature sensitivity, suggesting that these genetic changes could contribute to the virulence of DENV in infected individuals.
View Article and Find Full Text PDF
Article Synopsis
  • *This study created virus-like particles (VLPs) from the H5N6-Sichuan strain using a baculovirus-insect cell system and confirmed their composition through purification and analysis.
  • *The results showed that H5N6 VLPs produced significantly higher neutralizing antibody responses and immune reactions in mice, suggesting their potential as a broad-spectrum vaccine for H5Nx avian influenza.
View Article and Find Full Text PDF

genus has over one hundred genotypes and could cause several kinds of severe animal and human diseases. Understanding the role of conserved residues in the VP1 capsid protein among the genus may lead to anti-enteroviral drug development. The highly conserved residues were found to be located at the loop and ß-barrel intersections.

View Article and Find Full Text PDF
Article Synopsis
  • Highly pathogenic viruses pose a global threat, and vaccines are crucial for preventing infections, but their development is hindered by the need for high biosafety conditions.
  • This study developed pseudovirus systems for the SARS-CoV-2 and avian influenza virus H5, allowing researchers to safely assess vaccine efficacy and immunogenicity in a lower biosafety level.
  • The results showed that using pseudoviruses can accelerate vaccine development, helping to protect communities from dangerous emerging and re-emerging viral diseases.
View Article and Find Full Text PDF

As a neurotropic virus, enterovirus A71 (EV-A71) emerge and remerge in the Asia-Pacific region since the 1990s, and has continuously been a threat to global public health, especially in children. Annually, EV-A71 results in hand-foot-and-mouth disease (HFMD) and occasionally causes severe neurological disease. Here we reviewed the global epidemiology and genotypic evolution of EV-A71 since 1997.

View Article and Find Full Text PDF