Two Potential COVID-19 Vaccines Enter Final Stage Clinical Trials

Late-stage Phase II/III trials are currently underway in the UK, Brazil and South Africa and are due to start in the US,with the goal of delivery a COVID-19 vaccine in early 2021.

Image: Ulrike Leone / Pixabay

As the world races to develop an antidote for the coronavirus, two potential COVID-19 vaccines have passed early-stage clinical trials and are on schedule to be made available in early 2021.

ChAdOx1 nCoV-19

The vaccine, called ChAdOx1 nCoV-19, was conceived at Oxford University in the United Kingdom and will be manufactured by AstraZeneca.

In Phase I/II COV001 trial, the compound drug stimulated both neutralizing antibodies and active immune cells, or T-cells. Generating a robust immune response against the SARS-CoV-2 virus in all evaluated participants, while showing no significant side effects.

Late-stage Phase II/III trials are currently underway in the UK, Brazil and South Africa and are due to start in the US. Trials will define how well the vaccine will protect from the COVID-19 disease and measure safety and immune responses in different age ranges and at various doses.

If successful, the coronavirus vaccine will be made available early next year. More Info: AstraZeneca

mRNA-1273

The other vaccine that past pass early-stage clinical trials is being developed by Moderna. Identified as mRNA-1273, the medication induced anti–SARS-CoV-2 immune responses in all participants with no serious safety concerns identified.

The vaccine is designed to induce neutralizing antibodies to part of the protein the virus binds to enter human cells.

Moderna has completed the manufacture of the vaccine required to start the Phase 3 study, that it hopes to start this month. According to the Company’s press release, development for a COVID-19 vaccine remains on track to deliver doses, beginning in 2021. More Info: Moderna

Phases of Clinical Trials

  • Phase I trials are the first stage of testing in human subjects. They are designed to test the safety, side effects, best dose, and formulation method for the drug to a small group of 20–100 healthy volunteers. Phase I trials are not randomized, and thus are vulnerable to selection bias.
  • Phase II trials are performed on larger groups 50–300 and are designed to assess how well the drug works, as well as to continue Phase I safety assessments.
  • Phase III is designed to assess the effectiveness of the new intervention and, thereby, its value in clinical practice. The studies are randomized controlled multicenter trials on large patient groups 300–3,000 or more and are aimed at being the definitive evaluation of how effective and safe the drug is.
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