In the fight against COVID-19, a vaccine is a critical part of addressing the global health crisis by decreasing rates of infection, disease and death worldwide. Pfizer and BioNTech are leveraging our decades of scientific expertise and working together to make our COVID-19 vaccine candidate available as quickly and safely as possible. The Phase 3 clinical trial began in late July, and participants 12 and over are now eligible to participate.

After conducting the final efficacy analysis in our Phase 3 study, the mRNA-based COVID-19 vaccine candidate met all of the study’s primary efficacy endpoints. Primary efficacy analysis demonstrated the vaccine candidate to be 95% effective against COVID-19 beginning 28 days after the first dose.

On November 20, Pfizer and BioNTech announced they will submit a request to the U.S. Food and Drug Administration (FDA) for Emergency Use Authorization (EUA) of their mRNA vaccine candidate, which will potentially enable use of the vaccine in high-risk populations in the U.S. by the middle to end of December 2020.

Developing a potential breakthrough vaccine to help prevent COVID-19 is only possible through the dedicated work of thousands of individuals and those who volunteer to take part in research. We are committed to diversity in our clinical trial and ensuring that individuals from communities that have been most affected by COVID-19 have the opportunity to participate.

We are grateful to each of approximately 150 clinical trial investigators and their study teams who are partnering with us in this effort and to all of the participants who have volunteered, and will volunteer, to help make a difference for society.



Trial Locations

Trial Progress


Updated as of Monday, November 30, 2020 at 09:00am ET. Updates are made on a weekly basis.

Frequently Asked Questions

The Investigational Vaccine

What kind of vaccine is the investigational vaccine?

The investigational vaccine is an mRNA vaccine. It is a kind of vaccine that gives a body's cells instructions to make viral proteins that can be recognized by the immune system. It contains a small part of the genetic code for the SARS-CoV-2 spike protein. By delivering the mRNA to the body’s cells, the viral protein is expressed and an immune system response is generated against it, with the goal of preventing COVID-19 disease. The vaccine does not contain any live virus.

How are mRNA vaccines different than traditional vaccines?

There are many different types of vaccines used to help prevent infections, and all have the same goal: train your immune system to recognize and defend against organisms that cause disease by producing disease-fighting antibodies and activating immune cells, such as T-cells. Some conventional vaccines may be made up of weakened, dead, or noninfectious parts of a virus or bacterium. mRNA vaccines are different because they contain information about the infectious agent to give a body's cells instructions to make a viral protein that can be recognized by the immune system. 

The Clinical Trials

What was the objective of the Phase 1 portion of the clinical trial?

The phase 1 clinical trials began in the U.S. and Germany in April and were designed to evaluate the safety, tolerability, and potential efficacy of up to four mRNA vaccine candidates and to select which vaccine candidate and dose should be taken forward for future clinical study. The BNT162b2 candidate, at a 30 µg dose level in a two vaccination course was selected for phase 3 and also received U.S. Food and Drug Administration Fast Track designation.

What is the objective of the Phase 3 portion of the clinical trial?

The Phase 3 portion of the clinical trial is designed to determine if the BNT162b2 vaccine candidate is safe and effective in preventing COVID-19 disease. This part of the trial began July 27 and is estimated to enroll up to 44,000 participants. On November 18, Pfizer and BioNTech announced that, after conducting the final efficacy analysis in their ongoing Phase 3 study, their mRNA-based COVID-19 vaccine candidate met all of the study’s primary efficacy endpoints.

Why did you expand enrollment for the Phase 3 trial?

In September 2020, Pfizer expanded the enrollment of its Phase 3 pivotal COVID-19 vaccine trial to approximately 44,000 participants. This allowed for the enrollment of new populations, including adolescents as young as 16 years of age and people with chronic, stable HIV (human immunodeficiency viruses), Hepatitis C, or Hepatitis B infection. In October 2020, we received permission from the FDA to enroll adolescents as young as 12. By doing so, we are able to better understand the potential safety and efficacy of the vaccine in individuals from more ages and backgrounds.

How are you able to move with this speed in the trial?

Even though we are moving with extraordinary speed, preservation of high quality and safety standards is critically important throughout development. We are taking all of the regulatory and operational steps that we would normally take for all of our vaccine trials, maintaining the highest standards in our development process. This required enormous mobilization of Pfizer and BioNTech resources upfront at a scale never seen before. We are also working closely with regulatory agencies, providing near real time data and receiving review and advice more quickly than ever before, to support the development of this potential vaccine as quickly as possible.

Commitment to Safety

How are you monitoring the safety of trial participants?

Participant safety is paramount. As with all of our trials, we are following all of the rules and regulations in place to ensure participant safety. For example, the trial protocols are reviewed by regulatory authorities and approved by ethics committees or Institutional Review Boards, which are independent committees that review the methods proposed for research. In addition, the trial’s progress is closely monitored by both Pfizer and an outside group of independent experts called a Data Monitoring Committee or DMC. Trial investigators are also responsible for monitoring participants health, and participants in the trial have regular planned follow-up visits as part of the trial.

Commitment to Diversity

COVID-19 has disproportionately affected underrepresented populations. How are you addressing this in the trial?

We are committed to decreasing health disparities in underrepresented populations through our clinical trials.  We have selected investigative sites in diverse communities in the U.S. and globally that have been disproportionately affected by COVID-19, to help ensure that individuals in communities that have been most impacted have the opportunity to participate. A breakdown of the diversity of clinical trial participants can be found here. We have shared with our investigative sites the importance of recruiting individuals who fully represent the racial and ethnic diversity of their communities, and we are engaging patient advocacy partners and community groups to raise awareness about the importance of participation and representation.

Access to a Vaccine, Once Approved

When is the earliest the vaccine will be available to the public?

On November 20, we submitted a request to the U.S. Food and Drug Administration for an Emergency Use Authorization (or EUA) of our vaccine candidate. If accepted, this will potentially allow for use of the vaccine in high-risk populations in the U.S. by the middle to end of December 2020.

Who will get the vaccine first, if it is approved?

We are working with governments around the world to provide and distribute our vaccine, if authorized or approved. Those governments and local regulatory authorities would provide the vaccine as they determine is appropriate.

How much will the vaccine cost?

We will price our vaccine in a way to help governments ensure there is little to no out-of-pocket cost for the vaccine for their populations. It is also important to note that our COVID-19 vaccine development and manufacturing costs are entirely self-funded, with billions of dollars already invested in an effort to help find a solution to this pandemic.

Development Milestones

December 2, 2020

Pfizer and BioNTech Achieve First Authorization in the World for a Vaccine to Combat COVID-19

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November 20, 2020

Pfizer and BioNTech to Submit Emergency Use Authorization Request Today to the U.S. FDA for COVID-19 Vaccine

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November 18, 2020

Pfizer and BioNTech Conclude Phase 3 Study of COVID-19 Vaccine Candidate, Meeting All Primary and Secondary Efficacy Endpoints

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November 9, 2020

Pfizer and BioNTech Announce Vaccine Candidate Against COVID-19 Achieved Success in First Interim Analysis from Phase 3 Study

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September 15, 2020

Pipeline Advances and COVID-19 Vaccine Candidate Updates

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September 12, 2020

Proposal to Expand Clinical Trial Announced

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September 9, 2020

Data from Preclinical Studies of Vaccine Candidate

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September 8, 2020

Biopharma Leaders Unite to Stand with Science

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August 20, 2020

Positive Early Data from Phase 1/2 Study of Lead Vaccine Candidate Announced

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August 12, 2020

Peer-Reviewed Phase 1/2 Data Published Online in the Journal Nature

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July 27, 2020

Lead Covid-19 Vaccine Candidate Selected and Global Phase 2/3 Clinical Study Begins

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July 20, 2020

Early Positive Data from Ongoing Phase 1/2 Clinical Trial in Germany Announced

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July 13, 2020

Pfizer and BioNTech Granted Fast Track Designation

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July 1, 2020

Early Positive Data from Ongoing Phase 1/2 Clinical Trial in the U.S. Announced

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May 5, 2020

Pfizer and BioNTech Dose First Participants in the U.S.

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April 29, 2020

Testing of Vaccine Candidates in Humans Begins in Germany

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April 22, 2020

Regulatory Approval from German Authority to Begin Trial

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April 9, 2020

Pfizer and BioNTech Announce Further Details on Collaboration

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March 17, 2020

Pfizer and BioNTech Announce Plans to Co-Develop a Potential COVID-19 Vaccine

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March 13, 2020

Pfizer CEO Albert Bourla States 5-Point Plan to Battle COVID-19

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March 11, 2020

The World Health Organization (WHO) Declares the COVID-19 Outbreak a Global Pandemic

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August 16, 2018

Pfizer and BioNTech Establish Partnership to Develop mRNA Vaccines

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Preparing a Pandemic Vaccine Supply

In parallel with our vaccine development program, we are working with governments around the world to provide and distribute our vaccine, if approved. You can read more about those efforts in the press releases below:

Related Articles

Learn more about progress on our path to develop a COVID-19 vaccine.


For additional information about Pfizer, please see our filings with the U.S. Securities and Exchange Commission, including the information provided in the sections captioned “Risk Factors” and “Forward-Looking Information and Factors That May Affect Future Results”.