Pfizer Stock Drops 3.61% Amid RSV Vaccine Market Uncertainty

On April 7, 2025, Pfizer's stock experienced a 3.61% drop in pre-market trading, reflecting investor concerns and market dynamics.

Pfizer's stock has been under pressure due to regulatory challenges in the RSV vaccine market. The company, along with GSK, has decided to end their patent dispute over RSV vaccines, citing significant market shrinkage due to regulatory uncertainties. This decision follows a 2023 ruling by the UK High Court that invalidated two of GSK's RSV vaccine patents, which Pfizer had challenged.

The market for RSV vaccines has faced a significant setback due to changes in recommendations by the U.S. Centers for Disease Control and Prevention (CDC). In mid-2024, the CDC narrowed the age range for RSV vaccine recommendations, leading to a sharp decline in sales for both GSK's Arexvy and Pfizer's Abrysvo. This regulatory shift has had a profound impact on the financial performance of both companies, with Arexvy's sales dropping by 70% and Abrysvo's by 62% in the last three months of 2024.

Additionally, the appointment of Robert F. Kennedy Jr. as the U.S. Secretary of Health and Human Services (HHS) has introduced further uncertainty. Kennedy's anti-vaccine stance has led to delays and cancellations of key vaccine advisory meetings, further complicating the regulatory landscape for vaccine manufacturers like Pfizer.