Large Covid-19 Vaccine Trial Underway in U.S.

(ulleo, Needpix)

29 Dec. 2020. A biotechnology vaccine developer began enrolling participants in a large-scale clinical trial testing a vaccine to prevent Covid-19 infections. Novavax, in Gaithersburg, Maryland, plans to recruit some 30,000 participants in the U.S. and Mexico for the trial, particularly people at higher risk of infections.

Novavax creates vaccines protecting against infectious diseases with nanoscale particles of synthetic proteins designed specifically against the genetic code of their targets. The company says it clones the genetic sequence of its targets, then infects cells from reproductive systems of insects, with engineered viruses that grow only in those cells. The engineered viruses are designed to express surface proteins that trigger an immune response, which make up the nanoscale particles in their vaccines.

A key part of the Novavax vaccine is its Matrix-M adjuvant. This adjuvant is made with saponins, a substance derived from the bark of Quillaja saponaria Molina, a South American evergreen tree. Novavax says Matrix-M induces more immune system cells, producing more antibodies and T-cells when combined with the core vaccine. The adjuvant, says the company, makes possible lower doses of the vaccine.

The trial is testing Novavax’s vaccine candidate code-named NVX-CoV2373 with the Matrix-M adjuvant. The vaccine targets proteins on the SARS-CoV-2 virus spike surfaces, producing antibodies that block the spike proteins from binding with receptors in cells that begin the infection process. Tests in animals, including those reported by Science & Enterprise in August, demonstrated the vaccine’s activity. Preliminary findings from an early- and mid-stage clinical trial with 130 volunteers, says Novavax, shows the vaccine is well-tolerated and invokes a strong immune response.

Aiming for participants at higher risk of infections

The new late-stage clinical trial is enrolling 30,000 adult participants at 113 sites in the U.S. and Mexico. Two-thirds of participants are randomly assigned to receive two injections of NVX-CoV2373 with Matrix-M, three weeks apart, while one-third receives two placebo injections. The study team aims to enroll participants at higher risk of infections, including those over 65, with co-morbid conditions such as diabetes and hypertension, living in crowded conditions, or in close contact with essential workers, such as those in health care or grocery stores. In addition, researchers aim to recruit people in higher-risk races or ethnic groups including African-, Hispanic-, and native Americans.

The study team is looking primarily at Covid-19 infection rates of participants with any symptoms, beginning 28 days after injections. Researchers are also tracking reports of adverse effects, immune-system responses, and moderate to severe symptoms from Covid-19 infections.

With the trial now getting underway, Novavax runs the risk of potential participants preferring to wait for an authorized vaccine. “We recognize that volunteers considering our trial may have questions about the potential impact on their ability to receive an authorized vaccine when it becomes available to them,” says Gregory Glenn, Novavax’s research and development chief in a company statement. “We wish to reassure participants that we are working to ensure that their involvement in our trial does not negatively impact their ability to be vaccinated at the appropriate time.”

Novavax received early funding for NVX-CoV2373 from Coalition for Epidemic Preparedness Innovations in March 2020, with the U.S. Biomedical Advanced Research and Development Authority and Department of Defense providing $1.6 billion in July for manufacturing, storage, and distribution of 100 million doses.

More from Science & Enterprise:

• Device-Aided Covid-19 Vaccine Invokes Immune Response
• Global Vaccine Funds in Covid-19 Relief Bill
• Infographic – Vaccine Support Grows Across Ethnic Lines
• Univ. Lab, Biotech Partner on Covid-19 Vaccine Implant
• University Halts Covid-19 Vaccine Trials

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