What happened

Shares of BioNTech (BNTX -0.45%) climbed sharply higher on Wednesday, gaining as much as 11% earlier in the session, though the stock ended the trading day up 10.3%.

The biotechnology company is known for partnering with Pfizer (PFE -0.19%) to co-develop the BNT162b2 COVID-19 vaccine. BioNTech road Pfizer's coattails higher today as the company reported strong sales of its vaccine and raised its full-year forecast as a result.

A healthcare professional using a syringe to draw medication from vial.

Image source: Getty Images.

So what

Pfizer reported robust second-quarter results, with the vaccine generating $7.9 billion -- or roughly 42% of the company's revenue. The pharmaceutical giant also boosted its full-year guidance and is now expecting revenue of approximately $33.5 billion from the vaccine, up from its previous forecast of $26 billion. Needless to say, the vaccine gave both stocks a shot in the arm.  

Other news likely contributed to BioNTech's rise today. The Centers for Disease Control (CDC) recommended on Tuesday that children and fully vaccinated adults should begin wearing mask indoors again in areas with high COVID-19 transmission rates. This comes on the heels of a spike in the number of new cases, driven higher by the continued emergence of the delta variant as the dominant strain. 

Now what

The rising number of COVID-19 cases is increasing the chorus of calls for more people to get vaccinated. Additionally, Pfizer has been making the case for a third dose of the vaccine to boost immunity even further and is planning to submit additional data to U.S. regulatory agencies as early as August.

While regulators have yet to be convinced that an additional dose is needed, Pfizer and BioNTech could eventually earn billions of dollars if a third dose is eventually deemed necessary.