Novavax COVID-19 vaccine enters second round of human trials

gloved hands holding syringe, giving injection into a patient's arm

The biotechnology company Novavax will soon begin the second phase of human testing for its COVID-19 vaccine.

The so-called phase 2b clinical trial will include a group of 2,665 healthy adults in South Africa, as well as a group of 240 adults with HIV who are considered medically stable but whose immune responses may differ from individuals without HIV, according to a statement released by Novavax on Aug. 17. HIV advocacy groups have pushed for people with HIV to be included in clinical trials for COVID-19 vaccines, as companies like Moderna and Pfizer initially said they would exclude volunteers with the infection, Science Magazine reported. 

In a previous phase 1 safety trial of the Novavax vaccine, healthy volunteers given two doses of the vaccine showed only mild side effects, such as headache, fatigue, and tenderness or pain at the injection site, according to a report posted Aug. 6 to the preprint server medRxiv. According to this preliminary data, which has not been peer-reviewed, all of the phase 1 participants also generated neutralizing antibodies, which can prevent the virus from entering cells, after receiving a second dose of the vaccine. Novavax will continue to evaluate this immune response in the phase 2b trial in South Africa, as well as a phase 2 trial to be organized in the U.S. and Australia “in the near future,” according to the statement.


“Because South Africa is experiencing a winter surge of COVID-19 disease, this important Phase 2b clinical trial has the potential to provide an early indication of efficacy, along with additional safety and immunogenicity data for [the vaccine],” Dr. Gregory Glenn, president of research and development at Novavax, said in the statement. South Africa is the world’s fifth worst affected country in terms of COVID-19 cases and related deaths, with 583,653 reported cases and 11,677 deaths as of Aug. 17, Reuters reported. 

The Novavax trial in South Africa will be funded by The Bill & Melinda Gates Foundation, which is providing a $15 million grant, and The Coalition for Epidemic Preparedness Innovations (CEPI), which is providing funds to manufacture doses of the vaccine needed for the trial, according to the statement. 

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The vaccine, called NVX-CoV2373, contains proteins derived from the coronavirus spike protein, a structure that juts off the virus’s surface and plugs into cells to cause infection, according to the statement. In general, Novavax designs vaccines by attaching such proteins to microscopic particles that can be delivered into the body to trigger an immune response, according to The New York Times Coronavirus Vaccine Tracker.

Novavax also added an adjuvant to the vaccine — an extra ingredient that helps rally immune cells into action. Specifically, the adjuvant in NVX-CoV2373 contains a saponin, or a chemical compound derived from plants, according to the statement. Saponins can help summon immune cells to the injection site, where they spot foreign proteins, like the spike protein, and “present” those proteins to T cells; these T cells then remember what the proteins look like should a vaccinated person ever be exposed to the virus, according to a 2016 report in the journal Nature Communications.

Originally published on Live Science. 


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