DNA Vaccines for COVID-19 Shown Effective in Hamsters – Quicker Production and Lower Cost Than mRNA Vaccines

Currently available COVID-19 vaccines rely on mRNA strands to teach the human immune system to recognize the SARS-CoV-2 virus. Now researchers in PLOS Neglected Tropical Diseases report the successful development of a vaccine that instead uses DNA encoding the virus’s spike protein.

While both DNA and mRNA vaccines use genetic material that encodes part of a virus to elicit an immune response, DNA vaccines can often be produced and shipped faster and at a lower cost without the need for cold temperatures. Recent clinical studies have shown that DNA vaccines are safe and effective in the treatment of infections, including HIV-1, Zika virus, Ebola virus and influenza viruses.

In the new work, Shih-Jen Liu and Hsin-Wei Chen of the National Health Research Institutes, Taiwan, and colleagues developed a vaccine that uses DNA encoding the SARS-CoV-2 spike protein. To overcome the poor delivery of DNA to cells often seen with DNA vaccines, the team paired electroporation with the delivery of the DNA vaccination.

The researchers showed that mice and hamsters immunized with the new DNA vaccine developed long-lasting antibodies against the SARS-CoV-2 spike protein. Those antibodies peaked 8 weeks after immunization, but the levels remained relatively high at week 20. Hamsters that received two immunizations 3 weeks apart and exposed to COVID-19 after 7 weeks were protected from the virus and did not show any. loss of body weight. weight and less viral RNA in their lungs compared to animals that were not immunized.

“The DNA vaccine is thermally stable, does not require a cold chain and can induce a high level of long-term neutralizing antibody titers against SARS-CoV-2,” add the authors. “The DNA vaccine confers protective efficacy against SARS-CoV-2 infection in Syrian hamsters, which is a serious animal model of COVID-19 disease.”

Reference: “DNA vaccination induced protective immunity against SARS CoV-2 infection in hamsters” by Chai KM, Tzeng TT, Shen KY, Liao HC, Lin JJ, Chen MY, et al., May 27, 2021, PLOS Neglected Tropical Diseases .
DOI: 10.1371 / journal.pntd.0009374

Funding: This study was funded by the Department of Health and Welfare at LCL (No. MOHW-109-TDU-C222-000010) and the National Health Research Institutes at LSJ (No. IV-108-GP-02, IV-108 -GP-03, IV-108-GP-05) from Taiwan. The funders had no role in the design of the research, the collection and analysis of data, the decision to publish or the preparation of the manuscript.