Vaxcyte, a vaccine developer, saw its stock price rise by a third in a single day. Is there still room for growth?

Shares of Vaxcyte, a small vaccine developer, soared nearly 31% on October 5—reaching a 1.5-year high. The company announced the successful testing of a vaccine against pneumococcal infections, which cause a range of serious diseases. Against this backdrop, at least two Wall Street analysts raised their price targets for the company’s stock. The consensus forecast calls for a further 50% upside potential.

Vaxcyte's stock rose nearly 31% on October 5, reaching $73.8. This is the highest level since March 2025.

The rally began after the company announced that, according to preliminary data, its vaccine against pneumococcal infections in adults had shown promising results in the final phase of clinical trials.

The vaccine, called VAX-31, is designed to combat 31 strains of pneumococcal bacteria that can cause serious illnesses, including pneumonia, sepsis, meningitis, and endocarditis.

In clinical trials, Vaxcyte compared its vaccine candidate with Prevnar 20 from pharmaceutical giant Pfizer, which protects against 20 bacterial strains, and Capvaxive from the U.S.-based Merck, which covers 21 strains. Tests showed that for the 28 strains that VAX-31 “shares” with its competitors’ products, its protection was just as effective. At the same time, thanks to its unique components, Vaxcyte’s product outperformed both Prevnar 20 and Capvaxive.

The clinical data obtained “set a new standard for this class of vaccines and provide confidence in the potential approval” of VAX-31 by the U.S. regulatory authority, said Grant Pickering, CEO and co-founder of Vaxcyte. The company plans to submit a registration application in 2027, along with data from two additional studies and following a review of its manufacturing capabilities. In addition, Vaxcyte will receive results from the mid-phase trials of its vaccine in infants in the middle of next year, according to a press release.

In many countries around the world, vaccination against pneumococcal infections is covered by the government or insurance programs.

In light of the positive VAX-31 trial results, at least two Wall Street analysts have raised their price targets for Vaxcyte stock: Guggenheim raised its target by nearly 8% to $125, implying upside potential of more than 69%, while Needham raised its target by nearly 11% to $122, representing a 65% premium to current prices.

Both investment banks have reaffirmed their “buy” recommendations for the company’s stock. It has a total of seven “buy” ratings, and another analyst advises holding the stock. The average target price of $111 implies growth potential of more than 50%. Since the beginning of the year, Vaxcyte’s market value has soared by 60%.