What happened

Shares of Dynavax Technologies (NASDAQ:DVAX) jumped 26.4% on Friday following comments by researchers at Sinovac, a Chinese drug developer that's collaborating with Dynavax on a COVID-19 vaccine.

So what

In April, Dynavax and Sinovac agreed to collaborate to develop a vaccine for COVID-19. Dynavax is contributing an adjuvant that can boost immune responses in vaccinated patients, while Sinovac is contributing an inactivated coronavirus vaccine candidate. 

A doctor talking through a megaphone.

Image source: Getty Images.

In a Sky News article about Sinovac's progress published on Friday, Sinovac researcher Luo Baishan was quoted as saying its vaccine would likely pan out, responding: "Yes, yes. It must be successful ... 99% [sure]," when asked by reporters about the likelihood of its development producing an effective vaccine.

But Helen Yang, a senior director of investor relations at the healthcare company, struck a more cautious tone. When asked a similar question, she replied: "It's very hard to say, very difficult to say at the moment. There are uncertainties, but the data: so far, so good."

The race for a COVID-19 vaccine is significant because there have been over 5.8 million cases globally, including over 360,000 deaths, according to the Johns Hopkins Coronavirus Resource Center.

Now what

Dynavax's adjuvant is a synthetic form of DNA that is already used in Dynavax's approved hepatitis B vaccine, Heplisav-B, but that doesn't guarantee it will be similarly effective in helping Sinovac's COVID-19 vaccine succeed. 

Investors should also remember that Sinovac's vaccine is only in the earlier stages of development, and while it's shown promise in primates, more research in humans is necessary. Yang expects it to be "many months" before its current stage of research is complete, enabling Sinovac to advance it into the next stage of research involving more people. 

Their vaccine isn't the only one under development, either. Many companies are conducting their own research, including AstraZeneca (NASDAQ:AZN), which is working with Oxford University, and Moderna (NASDAQ:MRNA), which is advancing its vaccine candidate, mRNA-1273, into phase 2 trials in the United States. Because of the flurry of activity and uncertainty, investors ought to approach Dynavax cautiously.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.