Inovio Pharmaceuticals (NASDAQ:INO) has given different groups of investors some wildly varying stock performances this year. If you bought its shares at the beginning of 2020, your investment is up 421% year to date. 

On the other hand, during the summer, the stock was trading up by more than 1,200%. And if you grabbed some shares when they were near that multiyear high, you're now down by as much as 68%. Many shareholders who picked that period to open their positions are naturally disgruntled. The question for all investors (but perhaps especially for those who have held on since July) is: Can Inovio recover its upward momentum and become a millionaire-maker holding again?

Nurse giving patient COVID-19 vaccine injection.

Image Source: Getty Images.

Finally, some COVID vaccine progress

Inovio's most promising candidate is INO-4800, a DNA vaccine for protection against SARS-CoV-2. Yet ever since the company began developing it, it appeared that almost anything that could go wrong did go wrong.

The company (and the public) endured an excruciating wait for independent verification of INO-4800's phase 1 clinical trial results. Inovio sued the contract manufacturing organization it had partnered with, alleging it lacked the capacity to produce INO-4800, but was "holding hostage" the technology and data required to allow other manufacturers to do so. The FDA put a pause on the candidate's phase 2/3 clinical trial due to concerns about the specialized device required for inoculating patients with it. (The halt on the phase 2 section of that study has since been lifted.) And notable short-seller Citron Research alleged Inovio was a "dangerous stock promotion."

But now, it appears that Inovio's luck is about to change. At long last, on Dec. 24, INO-4800's phase 1 clinical results passed the peer-review process, and are now publicly available on The Lancet's website. According to the study, approximately 78% to 84% of healthy volunteers who received the experimental vaccine developed neutralizing antibodies against the coronavirus. In addition, 100% of participants developed measurable immune responses, and INO-4800 was well-tolerated with no incidences of serious adverse events.

Compared to Pfizer's or Moderna's coronavirus vaccines, which showed 100% neutralizing antibody response in phase 1, INO-4800 doesn't look that impressive in terms of efficacy. However, it has significant logistical advantages compared to those vaccines.

Vaccines developed using Inovio's DNA platform should be shelf-stable at room temperature for more than a year, and at 37 degrees Celsius (normal human body temperature) for more than one month. At standard refrigeration temperatures, INO-4800 could have a shelf life of more than five years.

Considering that half of the world's manufactured vaccines go to waste due to improper temperature control or issues during transport, that high level of stability could well give INO-4800 an edge over its competitors in the marketplace. The two coronavirus vaccines currently approved for emergency use by the FDA  -- BNT162b2 and mRNA-1273 -- both require below-freezing temperatures for long term storage. 

Right now, INO-4800 is in phase 2 clinical testing. The Department of Defense is fully funding the later stages of the investigation. To date, the company has not issued any press releases regarding pre-orders of INO-4800, but that may change soon given the news from the phase 1 study. 

What's the verdict? 

So far, coronavirus vaccines' ability to demonstrate efficacy (in terms of inducing the immune system to produce neutralizing antibodies) in early-stage clinical trials has correlated well with their success in later-stage trials. Now that researchers have independently verified INO-4800's results, we can expect that the candidate has a good chance of making it past phase 3. If this vaccine ever reaches approval, Inovio stock would arguably skyrocket.

Right now, the company only has a market cap of $1.7 billion despite having multiple candidates in its pipeline aside from INO-4800. That is incredibly low. Consider its competitor CureVac, whose market cap soared from $2.8 billion at its August IPO to $18.1 billion as of Dec. 24 due to vaccine hype. The company convinced the EU to sign a contract for 225 million doses of its candidate off just phase 1 data (though that deal is, of course, contingent on the vaccine earning regulatory approval). 

Overall, I do not expect that smallish positions in Inovio stock will make their holders wealthy. First of all, the company's progress toward a COVID-19 vaccine has been a bit slow compared to the field of competitors. However, Inovio shares definitely possess the potential to deliver triple-digit percentage returns if INO-4800 receives regulatory clearance. If you are a biotech investor looking for growth stock opportunities, or if you want to get into coronavirus vaccine stocks but missed their spectacular rally, it's not too late to buy shares of Inovio Pharmaceuticals. 

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.