What happened

Shares of pharma giant Pfizer (NYSE:PFE) fell by as much as 5.6% on Wednesday and closed the day's trading session down by 5.3%. While the broader stock market is feeling the pressure of a new surge in COVID-19 cases worldwide, one would expect Pfizer, a leader in the COVID-19 vaccine race, to benefit from these developments. However, investors are getting impatient with Pfizer, which has yet to release any data from its ongoing late-stage clinical trial for its coronavirus vaccine candidate, BNT162b2. 

So what

In early September, Pfizer's CEO, Albert Bourla, said in an interview that the company expected to know by the end of October whether BNT162b2 is safe and effective. And in an open letter posted on the company's website on Oct. 16, Bourla reiterated this sentiment while also emphasizing that efficacy data could come "earlier or later based on changes in the infection rates." With only a couple of days or so left to go in the month, the drugmaker has yet to release any data from this clinical trial to the public.

Hand filling syringe with liquid from glass vial.

Image source: Getty Images.

Of course, this doesn't mean that BNT162b2 failed to prove safe or effective. In fact, it seems Pfizer doesn't have an answer yet. During the company's third-quarter earnings conference call, Bourla said: "I can say today that the data monitoring committee has not been unblinded to efficacy data nor has it conducted any interim efficacy analysis today. But I want to be clear that after today's earnings call, we do not intend to speak publicly about interim analysis until we have a conclusive read-out from the data monitoring committee."

Now what

The fact that we don't yet know whether Pfizer's vaccine works is disappointing, and it isn't surprising to see some investors offloading shares of the pharma stock as a result. But it's essential to remain patient; after all, Pfizer is still one of the leaders in this race, and it has already signed supply agreements worth billions of dollars with several governments. Also, even if BNT162b2 flops, the company's prospects don't hinge on a single vaccine. Long term investors should focus on the company's overall lineup and pipeline. 

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.