Vaxcyte's vaccine beats rivals in late-stage trial

Pneumococcal bacteria still cause pneumonia and meningitis that kill people every year, even with vaccines already on the market. On Monday, a biotech called Vaxcyte said its experimental shot cleared a major hurdle. The vaccine, VAX-31, met every key goal in a Phase 3 trial of adults. Researchers tested it directly against Prevnar 20 and Capvaxive, the shots from Pfizer and Merck that currently dominate this market.

VAX-31 protects against 31 different strains of the bacteria. In the trial, it matched or beat Prevnar 20's immune response on every strain they share. That's a tough bar to clear, since Prevnar 20 already dominates this market. Vaxcyte's stock jumped roughly 35% that morning. This is still 'topline' data, the first look a company releases before the full numbers go through outside review.

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Will VAX-31's full data hold up once regulators and outside scientists pick it apart? Early trial wins occasionally lose their shine once complete datasets arrive. If VAX-31 holds up, Vaxcyte is positioned to take real market share. That share would come from two of the best-selling vaccines in the world.