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Which Vaccines Against COVID-19 Are in Human Clinical Trials?

Which Vaccines Against COVID-19 Are in Human Clinical Trials? content piece image
Credit: Vincent Ghilione on Unsplash.
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In the fight against the COVID-19 outbreak, caused by the SARS-CoV-2 pathway, the development of a safe and effective vaccine is considered a long-term strategy. The development, licensing and manufacturing of a vaccine is typically a lengthy process.

An increasing number of candidates are currently being evaluated against SARS-CoV-2 and are at different stages of the testing pathway.

As with any drug or biologic, a vaccine must undergo clinical trials, and these are often undertaken in three phases.

If you're unfamiliar with the drug development process, Technology Networks provides a comprehensive summary, available here.

Which candidates against COVID-19 are currently in clinical trials?

As of April 6, there are two vaccines in Phase I human clinical trials:

  • Recombinant novel coronavirus vaccine (Adenovirus Type 5 Vector) - NCT04313127

This Phase I clinical trial is a non-randomized dose-escalating study designed to assess the safety, reactogenicity and immunogenicity of recombinant novel coronavirus vaccine (Adenovirus Type 5 Vector) that is manufactured by the Beijing Institute of Biotechnology and CanSino biologics.

The trial will recruit 108 healthy subjects aged 18-60 years who are in good health and fulfil the eligibility criteria. All subjects will be enrolled into one of three cohorts, receiving an intramuscular injection of the candidate or a placebo on day one of the trial.

The trial’s estimated primary completion date is December 30, 2020. The estimated study completion date is December 20, 2022.

“Thanks to our collaborators and our diligent team, who worked almost around clock since late January to develop this vaccine candidate with sound scientific data to support IND filing,” – Xuefeng Yu, Chairman and CEO of CanSinoBIO in a press release.

The Phase I clinical trial is an open-label, dose ranging study designed to assess the safety, reactogenicity and immunogenicity of mRNA-1273 manufactured by ModernaTZ Inc. The candidate is a novel lipid nanoparticle (LNP)-encapsulated mRNA-based vaccine. It encodes for a full-length, prefusion stabilized spike protein of SARS-CoV-2.

The clinical trial is estimated to recruit 45 healthy participants, including males and non-pregnant females, aged 18-55 years who fulfil the eligibility criteria. The participants will be divided into three cohorts representing three dosages, 25 microgram (mcg), 100 mcg or 250 mcg.

On day one, subjects will receive an IM injection of 0.5 mL mRNA-1273 in the deltoid muscle and will be followed through 12 months after second vaccination (Day 394). Follow-up visits will occur one, two and four weeks post each vaccination (Days 8, 15, 29, 36, 43, and 57), as well as three, six and 12 months post second vaccination (Days 119, 209 and 394).

The primary objective of the trial is to evaluate both safety and reactogenicity of a two-dose vaccination schedule of mRNA-1273, given 28 days apart, across three dosages in the healthy subjects. The secondary objective is to evaluate the immunogenicity. This will be measured by Immunoglobulin G enzyme-linked immunosorbent assay ELISA to the SARS-CoV-2 S protein following a two-dose vaccination schedule of mRNA-1273 at Day 57.

The estimated primary completion date and estimated study completion date for the trial is June 1, 2021.

“This study is the first step in the clinical development of an mRNA vaccine against SARS-CoV-2, and we expect it to provide important information about safety and immunogenicity. We are actively preparing for a potential Phase 2 study under our own IND,” – Tal Zaks, MD, PhD, Chief Medical Officer at Moderna, in a press release.

Preclinical evaluation

Several other candidates are currently in preclinical evaluation stages.

Here, it's critical to fully understand how a vaccine candidate interacts with the immune system and to evaluate any potential toxicities before moving to human clinical trials.

A wide range of data is collected through preclinical evaluation, often utilizing laboratory animal models, to gather information pertaining to correct vaccine formulations and dosage.