Vaxcyte’s Pneumococcal Vaccine Surges Past Pfizer and Merck in Key Trial

Vaxcyte’s experimental pneumococcal conjugate vaccine, VAX-31, delivered highly positive results in a late-stage trial, surpassing expectations and sending the company’s shares soaring by over 50%. The Phase 3 OPUS-1 trial demonstrated that VAX-31 matched or outperformed existing vaccines from Pfizer and Merck on key metrics, establishing a strong position in the $8 billion pneumococcal vaccine market.

The trial, involving 3,572 adults aged 50 and older, showed that VAX-31 met non-inferiority endpoints compared to Pfizer’s Prevnar 20 and Merck’s Capvaxive. Notably, VAX-31 excelled on three unique serotypes, while narrowly falling short on two specific serotypes against Capvaxive. Analysts from Mizuho and Leerink Partners described the results as ‘highly impressive’ and a ‘near best-case scenario,’ suggesting the vaccine could become a market leader.

Leerink Partners highlighted that VAX-31’s success sets a new competitive standard, making it likely that physicians and patients will prefer it over existing options due to its broader protection. The firm also noted that Vaxcyte’s higher bar for non-inferiority assessments further strengthens its market position. Vaxcyte plans to release additional trial results in the first half of 2027 and aims for a commercial launch by 2028.

Vaxcyte’s stock surged in pre-market trading, reaching around $86, up from $56 at the end of the previous week. Analysts predict the stock could climb even higher, potentially reaching $90-100. The company’s platform also includes other vaccine candidates, such as a Group A strep vaccine in Phase 1 testing, which further bolsters its growth prospects.