What happened

Shares of Inovio Pharmaceuticals (NASDAQ:INO) were sinking 6.6% as of 3:47 p.m. EST on Monday. The decline came after analysts gave mixed reviews to the biotech's phase 1 data from COVID-19 vaccine candidate INO-4800. These early-stage results were published in The Lancet's online clinical journal EClinicalMedicine on Dec. 24.

So what

Piper Sandler analyst Christopher Raymond views INO-4800 as an "also-ran" compared to leaders in the coronavirus vaccine race. He remains highly skeptical of Inovio's prospects with its COVID-19 vaccine candidate.

Scientist holding vaccine vial with syringe and needle

Image source: Getty Images.

Cantor Fitzgerald analyst Charles Duncan thought that Inovio's phase 1 results for INO-4800 didn't show as much potency as other coronavirus vaccines. He wrote to investors that it's possible that INO-4800 could hold potential as a third-generation or booster COVID vaccine. But Duncan thinks the jury is still out on those prospects.

On the other hand, H.C. Wainwright analyst Raghuram Selvaraju saw the early-stage data for INO-4800 as "very promising." Selvaraju wrote to investors that Inovio's experimental coronavirus vaccine produced immune responses in all vaccinated participants and demonstrated "excellent safety and tolerability."

Which analyst's view is right? It remains to be seen. However, INO-4800 will need to achieve exceptionally high efficacy in late-stage testing to be competitive against the COVID-19 vaccines from Pfizer and Moderna that have already won U.S. Emergency Use Authorization.

Now what

Inovio's shares have fallen nearly 70% over the last six months. The key to a rebound for the biotech stock is for INO-4800 to deliver unmistakably positive results that set it apart from other vaccines. Inovio is currently conducting phase 2 studies of the vaccine and hopes to advance it into late-stage testing in 2021.

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.