What is COVID-19?
SARS-CoV-2, the virus that sparked a global outbreak in late 2019, causes the disease known as “coronavirus disease 2019” or “COVID-19.”1 COVID-19 is a disease that can spread quickly with varying symptoms that can feel similar to when you have a cold, the flu, or pneumonia. Most people with COVID-19 experience mild symptoms, but some people become severely ill.2
Our Commitment to Fighting COVID-19
From the beginning of the pandemic, we understood that helping to fight COVID-19 would require the power of science and unprecedented collaboration among scientists, companies, governments, and other stakeholders around the world.
Today, Pfizer remains at the forefront helping to address the ongoing burden of COVID-19 through a prescription treatment option, and mRNA vaccine technology in collaboration with BioNTech. While significant progress has been made, we continue to work tirelessly to help reduce the global impact of COVID-19.
Making the Impossible Possible
COVID-19, a contagious respiratory disease: At the beginning of the pandemic, it was important to get people vaccinated to help prevent COVID-19 and severe illness including hospitalization and death.3 That’s why, in 2020, we set out to make the impossible possible. In collaboration with BioNTech, we delivered an innovative COVID-19 vaccine to the world using messenger RNA (mRNA) technology. mRNA is a molecule that contains instructions that direct a person’s cells to make a protein using the cells’ natural machinery.4 COVID-19 vaccines contain mRNA that teaches your body how to make the spike protein of the SARS-CoV-2 virus. The spike protein is recognized by your immune system as foreign, so your body learns how to defend itself if it encounters the real virus later helping to protect against severe outcomes of COVID-19.3,5
SARS-CoV-2, the virus that causes COVID-19, is always evolving, so COVID-19 vaccines can be updated to match more recently circulating strains as recommended by independent global and regional regulatory bodies.6,7 mRNA technology allows vaccines to be quickly adapted to target evolving strains of the virus.8
In collaboration with BioNTech, Pfizer worked with tremendous urgency and an uncompromising focus on quality, coordinating closely with trial participants and investigators, regulatory bodies, other companies, and governments to bring a COVID-19 vaccine forward. Our success was made possible in part due to Pfizer’s longstanding history in vaccine research, development, and delivery, which dates back more than a century. We are proud to have been such a significant part of the global response.
COVID-19 Prescription Treatment Option: In early 2020, recognizing the urgency of the COVID-19 pandemic, Pfizer also initiated a drug discovery program in an effort to develop a prescription treatment option for SARS-CoV-2 virus, complementing our vaccination efforts as part of a multi-pronged approach to tackling the pandemic.
Prescription treatment options are available for eligible patients – the treatment developed by Pfizer works to block the activity of an enzyme that the SARS-CoV-2 virus needs to multiply.9
We remain committed to continuing research and working toward broad, equitable, and affordable access to prescription treatment options for eligible patients around the world.
For those who do get COVID-19, especially those who are at high risk for progression to severe illness, it’s important to speak with a healthcare professional about available prescription treatment options quickly after symptom onset.
Getting Ahead of COVID-19
COVID-19 still leads to severe illness, hospitalizations, and death in some people and continues to be a healthcare burden. It is important for eligible individuals to stay up to date with recommended COVID-19 vaccination, especially for those at high risk of severe COVID-19 outcomes.
Our goal is to stay ahead of the virus by leveraging mRNA technology, which is well situated to address respiratory viral illnesses like COVID-19 because only the mRNA sequence of the vaccine requires updating to match emerging strains.10
Pfizer is poised for the future to produce updated formulas of COVID-19 vaccines in a timely manner that more closely match the latest circulating strains, as global regulatory bodies dictate.
We continue to gather evidence on the risk-benefit profile of COVID-19 vaccines and monitor the real-world impact. We are also researching another prescription treatment option for COVID-19.
- What are the symptoms of COVID-19?
According to the Centers for Disease Control and Prevention (CDC), common COVID-19 symptoms include:11
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Sore throat
- Fatigue
- Muscle or body aches
- Headache
- New loss of taste or smell
- Congestion or runny nose
- Nausea or vomiting
- Diarrhea
Call your healthcare provider right away after testing positive; they'll assess your risk factors (age, health conditions) and symptoms.
- Why do we need both COVID-19 vaccines and prescription treatment options?
While vaccines are one of the best ways individuals can help reduce the risk of infection, COVID-19 cases are still possible, and some people are at high risk for severe outcomes from COVID-19 if an infection occurs.3,12 Therefore, it is important to have access to COVID-19 vaccines and prescription treatment options. COVID-19 vaccines are the first step to help prevent COVID-19 and potential severe outcomes. If you think you could have COVID-19 and are at high risk for severe illness talk to your healthcare provider right away to find out if you’re eligible for a prescription treatment option.
- If I’m vaccinated and have COVID-19, am I eligible for a prescription treatment option?
Even if you are vaccinated, you may be eligible for a prescription COVID-19 treatment option if an infection occurs. Talk to your doctor for individual medical advice.
- Why should I get vaccinated if I am eligible to take a prescription treatment option if I test positive for COVID-19?
Clinical and real-world data show that COVID-19 vaccines can help protect against COVID-19, particularly against the risk for severe illness and hospitalization.13,14,15 However, if you do get sick and test positive for COVID-19, have symptoms of COVID-19, and are at high risk for progression to severe illness, you should speak with your doctor to find out if you’re eligible for a prescription treatment option as soon as possible, as treatment must be started within 5-7 days of symptom onset.16
- What are the possible side effects of mRNA COVID-19 vaccines?
Side effects may vary depending on the individual. After vaccination with authorized or approved mRNA COVID-19 vaccines, there have been rare cases of heart inflammation (myocarditis and pericarditis), usually appearing in adolescent and young adult males within 7 days after receiving the second dose of an mRNA COVID-19 vaccine.17
Severe allergic reactions can happen. People sometimes faint after vaccination. Pain, swelling, and redness where the shot is given, fever, tiredness (fatigue), headache, chills, muscle pain, joint pain, nausea, vomiting, and swollen lymph nodes can happen after COVID-19 vaccination. CDC, FDA, other agencies and researchers closely monitor the safety of vaccines in the United States through ongoing analysis of data, early detection of potential safety concerns and prompt public health action if needed.18
- What are the possible side effects of the COVID-19 prescription treatment option?
The most comment side effects of the prescription treatment option developed by Pfizer include altered sense of taste (such as metallic, bitter taste) and diarrhea. Taking the prescription treatment option with certain medicines can lead to serious or life-threatening side effects, or affect how it or other medicines work, including hormonal birth control. Serious side effects include anaphylaxis and liver problems. It is very important to tell your healthcare professional about all the medicines you are taking, including prescription and over-the-counter medicines, vitamins, and herbal supplements, because additional laboratory tests or changes in the dose of your other medicines may be necessary during treatment with the COVID-19 prescription treatment option. Your healthcare professional can advise whether the prescription treatment option may be right for you.
The information contained on this page is not meant to be promotional and is provided for your general information only. It is not intended as a substitute for seeking medical advice from a healthcare provider. Pfizer is not in the business of providing medical advice and does not engage in the practice of medicine. Pfizer under no circumstances recommends particular treatments for specific individuals and in all cases recommends consulting a physician or healthcare center before pursuing any course of treatment.
- References
- Naming the coronavirus disease (COVID-19) and the virus that causes it. WHO. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it. Accessed January 2026.
- About COVID-19. CDC. https://www.cdc.gov/covid/about/index.html. Accessed January 2026.
- Benefits of Getting Vaccinated. CDC. https://www.cdc.gov/covid/vaccines/benefits.html. Accessed January 2026.
- Understanding COVID-19 mRNA Vaccines. National Human Genome Research Institute. https://www.genome.gov/about-genomics/fact-sheets/Understanding-COVID-19-mRNA-Vaccines. Accessed January 2026.
- COVID-19 Vaccine Basics. CDC. https://www.cdc.gov/covid/vaccines/how-they-work.html. Accessed January 2026.
- Tracking SARS-CoV-2 variants. WHO. https://www.who.int/activities/tracking-SARS-CoV-2-variants. Accessed January 2026.
- Statement on the antigen composition of COVID-19 vaccines. WHO. https://www.who.int/news/item/15-05-2025-statement-on-the-antigen-composition-of-covid-19-vaccines. Accessed January 2026.
- Szabó GT, Mahiny AJ, Vlatkovic I, et al. COVID-19 mRNA vaccines: platforms and current developments. Mol Ther. 2022;30(5):1850-1868. https://doi.org/10.1016/j.ymthe.2022.02.016.
- Owen DR, Allerton CMN, Anderson AS, et al. An oral SARS-CoV-2 Mproinhibitor clinical candidate for the treatment of COVID-19. Science. 2021;374(6575):1586-1593. https://doi.org/10.1126/science.abl4784.
- COVID-19 mRNA Vaccine Production. National Human Genome Research Institute. https://www.genome.gov/about-genomics/fact-sheets/COVID-19-mRNA-Vaccine-Production. Accessed January 2026.
- Symptoms of COVID-19. CDC. https://www.cdc.gov/covid/signs-symptoms/index.html. Accessed January 2026.
- People with Certain Medical Conditions and COVID-19 Risk Factors. CDC. https://www.cdc.gov/covid/risk-factors/index.html. Accessed January 2026.
- Falsey AR, Frenck RW Jr, Walsh EE, et al. SARS-CoV-2 neutralization with BNT162b2 vaccine dose 3. N Engl J Med. 2021;385(17):1627-1629. https://doi.org/10.1056/NEJMc2113468.
- Tartof S, et al. Estimated Effectiveness of the BNT162b2 XBB Vaccine Against COVID-19. JAMA Intern Med. 2024. 2024;184;(8):932-940. doi:10.1001/jamainternmed.2024.1640.
- Keane A, et al. Effectiveness of BNT162b2 vaccine for preventing COVID-19–related hospitalizations: A test-negative case–control study. Vaccines (Basel). 2024;12(6):657. https://doi.org/10.3390/vaccines12060657
- COVID-19 Treatments and Therapeutics. U.S. Department of Health and Human Services. https://www.hhs.gov/coronavirus/covid-19-treatments-therapeutics/index.html. Accessed January 2026.
- Safety Considerations for COVID-19 Vaccines. CDC. https://www.cdc.gov/covid/hcp/vaccine-considerations/safety-considerations.html. Accessed August 26, 2026.
- How Vaccine Safety Monitoring Works. CDC. https://www.cdc.gov/vaccine-safety-systems/about/monitoring.html. Accessed January 2026.
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