Vaxcyte is exploding higher following the release of positive topline data from its pivotal Phase 3 OPUS-1 trial, which showed that its 31-valent pneumococcal vaccine candidate, VAX-31, met all prespecified primary endpoints. The company announced these results overnight on October 4, demonstrating that the vaccine generated immune responses comparable to established rivals Prevnar 20 and Capvaxive. This development has prompted significant market enthusiasm, including a notable increase in call option activity and analyst commentary suggesting the company is well-positioned to capture a portion of a $3 billion to $6 billion market.