- Novavax on Tuesday said an experimental coronavirus vaccine it has been developing led to encouraging immune responses in healthy adults given the shot in an early-stage trial.
- Vaccination led to mostly mild side effects and, after a second dose, resulted in stronger antibody responses than those seen in the blood of patients with COVID-19, Novavax said. The company has submitted more detailed results for publication online and in a medical journal.
- Other groups, including Moderna, Pfizer and partner BioNTech, and the University of Oxford, have reported similar initial findings. But Novavax, which recently received $1.6 billion from the Trump administration for its coronavirus work, is the first so far to disclose results from a trial testing a protein-based vaccine.
The leading coronavirus vaccine developers have gotten ahead either because they've turned to newer technologies or because they started development work early on.
Moderna and German firm BioNTech, for instance, already have candidates in large, late-stage tests in part due to how their vaccines are designed and made. Novavax, meanwhile, falls into the latter camp, having started its work on a coronavirus shot in January.
The lesser-known Maryland drugmaker is taking a more traditional approach, using viral proteins rather than genetic code to train the body against coronavirus infection.
Study results disclosed Tuesday, from a small trial meant to show the vaccine's safety and ability to generate an immune response, appeared promising. They are not, however, proof the shot protects against the virus or COVID-19.
In a Phase 1 study conducted in Australia, 131 healthy adults aged 18 to 59 were randomized into one of five groups, receiving either a placebo, a low vaccine dose or a high vaccine dose. Four of the five groups were given two either placebo or vaccine shots, spaced 21 days apart, while two groups got an immune-boosting adjuvant as well.
All study participants who received two vaccine doses developed antibodies that can neutralize the coronavirus. Importantly, for those who also received the adjuvant, peak antibody levels were higher on average by about four times than what was observed from samples taken from recovered COVID-19 patients.
Exactly what level of antibody response is needed to protect against coronavirus infection or disease isn't known. But scientists view so-called convalescent sera as a useful guidepost to predict whether experimental vaccines could be effective.
"We think this is a very good anchor to understand our immune response data," Gregory Glenn, Novavax's head of R&D, said on a conference call. The antibody levels elicited from vaccination were "certainly in line with what you might expect to be protective," he added.
Novavax also saw evidence of responses from immune T cells, which are thought to be important in building protective immunity. Novavax only measured for those responses in a "subset" of participants, however, and didn't specify in its presentation how many were analyzed.
Like other coronavirus vaccines for which results are available, Novavax's led to side effects like fatigue, headache and muscle pain in most patients given two shots. Several participants had side effects deemed severe, indicating their reaction caused discomfort and prevented daily activity.
No serious adverse events were reported, according to Novavax. "Overall, it's our assessment this is a very good safety profile for a vaccine," Glenn said.
Novavax has spent three decades unsuccessfully trying to develop a vaccine for other viral diseases, but now is on the brink of potentially having its first product, an influenza shot called Nanoflu.
Despite that mixed track record, the drugmaker has gotten one of the largest checks from the U.S. government's aggressive Operation Warp Speed project, meant to speed coronavirus vaccine development. All told, the firm has received some $2 billion in external funding and seen its shares, worth less than $20 in May, soar to trade at $157 apiece.
As with the other vaccine developers to disclose early results, Novavax doesn't know whether its vaccine will work in the larger studies needed to prove a drug's effectiveness. But, like its rivals, the company is moving much faster than the norm to start additional tests.
It plans to begin a Phase 2 trial in 1,500 adults in the U.S. and Australia, and expects a global efficacy trial could begin in September, Stanley Erck, Novavax's CEO, said.
By then, several other companies, including AstraZeneca and Johnson & Johnson, could have also begun large Phase 3 trials.