Vaxcyte(PCVX) Plunges 8.96% on Mixed Vaccine Study Results

Vaxcyte(PCVX) shares plummeted 8.96%, hitting their lowest level since October 2022, with an intraday decline of 10.19%.

Vaxcyte's stock has experienced a significant decline due to mixed results from a phase II study on its investigational pneumococcal conjugate vaccine (PCV) in healthy infants. The vaccine, VAX-24, showed robust immune responses and met the non-inferiority criteria for most serotypes, but failed to meet these criteria for four out of the 24 serotypes compared to Pfizer’s Prevnar 20. This mixed outcome has been a major factor in the decline of PCVX's share price.

Additionally, the resignation of a senior FDA official has contributed to broader sector pressures, affecting biotech stocks, including Vaxcyte. The departure of a key regulatory figure has raised concerns about the regulatory environment and potential delays in approval processes, further impacting investor sentiment towards the company.