Pfizer and BioNTech Move Closer to a Single-Shot Flu–COVID Vaccine: What Investors Should Watch

Pfizer Inc (PFE), Biontech Se Sponsored Adr (BNTX) announced an update on their ongoing clinical study.

Pfizer-BioNTech Advance Combo Vaccine Strategy With New Early-Stage Data Milestone

1. Study Overview

This Phase 1/2 trial, officially titled “A Phase 1/2 Randomized, Double-Blinded Study to Evaluate the Safety, Tolerability, and Immunogenicity of Modified RNA Vaccine Candidates Against Influenza and COVID-19 in Healthy Individuals,” tests how Pfizer and BioNTech’s flu and COVID-19 vaccines work when given alone or as a single combined shot. The study focuses on safety and immune response in healthy adults, aiming to support a future one-dose seasonal vaccine strategy that could strengthen the companies’ positioning in the post-pandemic vaccine market.

2. Intervention/Treatment

The study compares several types of shots: an investigational COVID-19 vaccine, an investigational influenza vaccine, and a new investigational combination vaccine that targets both flu and COVID-19 in one dose. These are benchmarked against currently licensed Pfizer-BioNTech COVID-19 vaccines and standard flu vaccines. The goal is to find the best dose and mix that offers strong protection with a single annual visit.

3. Study Design

This is a randomized trial, meaning participants are assigned by chance to different vaccine options. It uses a parallel design, so each group receives one assigned shot rather than rotating through multiple options. The study is “double-blinded” for all parties involved, so participants, doctors, and outcome assessors do not know who received which vaccine, limiting bias. The main aim is prevention: to see if these vaccines, alone or combined, can safely trigger an immune response strong enough to support future protection against both flu and COVID-19.

4. Study Timeline

The trial began after initial submission on 7 February 2025, moving rapidly into dosing and follow-up. The primary follow-up phase runs for about six months per participant, aligned with seasonal vaccine planning. The study is now listed as completed, and the most recent update to the record came on 23 January 2026, signaling that data collection is done and analysis is underway. Results have not yet been posted, so investors are still waiting for headline safety and immune-response readouts.

5. Market Implications

For Pfizer (PFE) and BioNTech (BNTX), completion of this early-stage combo vaccine trial is an important step toward defending and possibly expanding their respiratory vaccine franchises as COVID-19 demand normalizes. A successful combined flu-COVID shot could raise long-term adherence, simplify distribution, and support pricing power relative to single-pathogen vaccines. This would help both companies compete against other large vaccine players, including Moderna and traditional flu vaccine makers, that are also pursuing combination respiratory shots. In the near term, the update may support sentiment by reinforcing the pipeline story, but the real stock impact will hinge on the eventual safety and immune-response data, and on whether regulators allow a streamlined path into larger Phase 3 trials ahead of future flu seasons.

The study has been completed and its record was recently updated, with further details available on the ClinicalTrials portal.

To learn more about PFE’s potential, visit the Pfizer Inc drug pipeline page.