What happened?

Shares of Inovio Pharmaceuticals (NASDAQ:INO) are down by 6.2% as of 10:43 a.m. EDT, despite the company not reporting any news. We can probably attribute these losses to a Tweet from Citron Research, which is run by short-seller Andrew Left. 

So what

In the Tweet, Citron Research claims Inovio's stock will fall back to $5, which would be a significant drop from its current levels. The biotech's shares are worth $16.09 apiece as of this writing. Why think Inovio's stock will fall off a cliff? Citron Research mentions that other companies looking to develop vaccines for COVID-19 are currently running late-stage clinical trials that feature thousands of participants. For instance, Moderna started a phase 3 study in July, and the company said it would enroll up to 30,000 participants.

five downward pointing arrows on a blackboard.

Image source: Getty Images.

Meanwhile, AstraZeneca and the partnership of Pfizer and BioNTech will enroll up to 30,000 and 44,000 participants to their ongoing clinical trials, respectively. By contrast, Inovio's COVID-19 candidate, INO-4800, was tested in a phase 1/2 clinical trial with only 40 volunteers.

Now what

Inovio said it would kick off a phase 2/3 study this month, but the company has yet to do so. The biotech does plan to produce at least 100 million doses of its candidate next year. However, as Citron Research points out, other companies seem far ahead of Inovio in this race. Pfizer's CEO, Albert Bourla, claimed the company will know whether its vaccine works by the end of October. If it does, it could obtain regulatory approval or emergency use authorization within the next few months.

The other players in this race also seem more likely to launch their products on the market before Inovio. While some unforeseen event could prevent them from doing so, thereby allowing Inovio to grab the lead (clinical trials are, after all, rife with potential pitfalls), there's no reason to suppose something like that will happen. That being said, the market opportunity is vast, which means Inovio could still profit in the long run. But as things stand, investors looking for exposure to the coronavirus vaccine race would be better off staying away from Inovio and choosing one of the other top contenders.