New vaccine in final trial stage

The Maryland biotech Novavax is starting a final, so- called Phase 3 clinical trial in the United States and Mexico for its experimental coronavirus vaccine, the company announced Monday.

The little-known firm, which has never brought a vaccine to market before, received up to $1.6 billion from the federal government’s Operation Warp Speed this summer to expedite development. The company reported robust results in earlier phases of its trial, showing that the vaccine prompted strong immune responses in monkeys and people.

The company began a Phase 3 trial of 15,000 people in Britain in September and expects to report preliminary results from that study in the first quarter of next year. It had intended to start its U.S. trial in October but delayed it because of manufacturing problems.

The Novavax vaccine, known as NVX- CoV2373, works differently than the ones by Pfizer and other companies that have already been shown to be effective. It contains artificially produced viral proteins, along with an immune-boosting compound derived from the soapbark tree.

The vaccine, given in two doses, three weeks apart, is designed to teach the immune system to recognize the protein. Later, if vaccinated people get infected with coronaviruses, their antibodies can attack them, while immune cells can destroy virus-harboring cells.

NVX- CoV2373 must be kept refrigerated but does not require freezing, making its storage easier than the Moderna and Pfizer

BioNTech vaccines, which have to be transported at ultracold temperatures.

Three other proteinbased coronavirus vaccines are also in Phase 3 trials in Australia, Canada and India.

Novavax will run its trial at 115 sites in the United States and Mexico, enrolling as many as 30,000 people. Two-thirds will receive the experimental vaccine, and the rest a placebo. Novavax said it would recruit a diverse group, including Black and Latino volunteers. They plan for onequarter of their participants to be older than 65.

“With the COVID-19 pandemic raging around the globe, this trial is a critical step in building the global portfolio of safe and effective vaccines to protect the world’s population,” Stanley C. Erck, president and chief executive of Novavax, said in a statement.