Dr. Sonia Macieiewski (R) and Dr. Nita Patel, director of antibody detection and vaccine development, is testing a sample of an airway virus, one of the labs for which a vaccine was developed, at the Novavax Laboratories in Rockville, Maryland on March 20, 2020.
Andrew Caballero-Reynolds | AFP | Getty Images
Novavax announced on Tuesday that its potential vaccine for the prevention of Covid-19 triggered a promising immune response in an early clinical trial. However, the biotech company's shares fell briefly due to security concerns.
The phase 1 study included 131 healthy participants between the ages of 18 and 59 at two locations in Australia. Novavax said 106 participants received one of four dose levels of the potential vaccine, NVX-CoV2373, with or without adjuvant, an ingredient that improves the immune response. The remaining 25 patients received a placebo.
Participants received two doses of the potential vaccine by intramuscular injection approximately 21 days apart.
The vaccine produced neutralizing antibodies, which researchers believe are necessary to build immunity to the virus, and killer T cells, the company said. In addition, the producing neutralizing antibodies were higher than in people who have recovered from Covid-19. The immune response was also stronger for those who had the adjuvant, the company said.
Novavax said the vaccine was well tolerated and no serious adverse events were reported. Most patients reported sensitivity and pain when injected after the first dose, although some patients also reported headache, fatigue, or muscle pain. Only one participant in the study had mild fever after a second dose, the company said. Earlier media reports and analysts identified eight possible hospitalizations related to the study, but the company said no patients were hospitalized.
The company's shares fell up to 32% in after-hours trading before recovering later and rising more than 2%.
Public health officials say there will be no return to "normal" until there is a vaccine.
Novavax is among several companies that, according to Johns Hopkins University, want to develop a vaccine against the virus that infected more than 18 million people worldwide and killed at least 694,715 people by Tuesday. According to the World Health Organization, more than 150 vaccines are being developed worldwide, of which at least 25 have already been studied in humans.
The announcement comes less than two weeks after pharmaceutical companies Pfizer and Moderna announced that they have started their late-stage trials for potential coronavirus vaccines. These studies will include approximately 30,000 participants.
"Phase 1 data shows that NVX-CoV2373 with our Matrix-M adjuvant is a well-tolerated COVID-19 vaccine with a robust immunogenicity profile," said Gregory Glenn, Novavax Research and Development President, in a statement on Tuesday.
While Novavax's data looks promising, scientists are warning that questions remain about how the human body reacts when it is infected with the virus. The answers could have important implications for vaccine development, including how quickly they can be made available to the public.
One question among scientists is whether antibodies produced in response to Covid-19 offer protection against re-infection.
Scientists expect antibodies to provide some protection against Covid-19, but they can't say for sure yet, since the virus was only discovered seven months ago.
The Novavax vaccine contains synthesized parts of the surface protein that the coronavirus infects humans with.
Last month, the U.S. government announced as part of the Trump administration's Operation Warp Speed Initiative that it would pay Novavax $ 1.6 billion to develop and manufacture the potential vaccine, with the goal of 100 by early next year Dispense millions of cans.
The money will also cover the cost of running a late stage trial that could start as early as October.
The company has announced that it will start a phase 2 trial in several countries if the trial were successful at an early stage.