What happened

Shares of Novavax, Inc. (NASDAQ:NVAX), a clinical-stage biotech focused on novel vaccine development, jumped 24.6% higher as of 11:50 a.m. EDT on Tuesday. Investors are cheering in response to the company's announcement that it will hold a conference call next week to discuss recent progress with its RSV F vaccine.

So what 

The respiratory syncytial virus sends a staggering number of older adults and infants to hospitals each year, but a vaccine that effectively prevents infections has yet to emerge. Novavax came awfully close with a mid-stage study that just crossed the threshold for statistical significance, but the stock cratered last year when the RSV F vaccine couldn't repeat the success in a larger study.

Person looking up at a series of upward sloping arrows.

Image source: Getty Images.

An effective RSV vaccine could easily generate several billion in annual sales, and investors send this stock jumping at the slightest hint an application for approval of its candidate might eventually reach the Food and Drug Administration. Today's jump isn't in response to any actual data, at least not yet. Simply announcing a call to discuss top-line data from a mid-stage clinical trial is enough to ignite hope.

Now what

On July 24, 2017, management intends to present results from the phase 2 safety and immunogenicity trial with its RSV F vaccine in adults over 60 years of age. While the call will be worth a listen, it won't tell us a great deal about the candidate's chances of eventually earning an approval. Previous studies have already shown the vaccine is safe and that it stimulates immune systems to create RSV-fighting antibodies.

In a rational market, the only data that would inspire a stock movement like the one we've seen today would be results from the ongoing, late-stage maternal immunization study. Investors better settle in for a long wait. According to today's announcement, the pivotal trial, which involves dosing women while they're pregnant and then measuring RSV infection rates among their babies, is still enrolling patients.

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.