Pfizer, Inc., and ModernaTX, Inc.
Type of vaccine:
mRNA vaccines are a new type of vaccine to protect against infectious diseases.
These vaccines teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies.
This immune response, which includes making antibodies, protects us from getting infected if the real virus enters our bodies.
Number of shots:
2 shots, 21 days apart
Shot into the muscle of the
Tools against the virus
COVID-19 vaccines are highly effective at preventing severe illness, hospitalizations, and death.
Scientists are currently investigating Omicron, including how protected fully vaccinated people will be against infection, hospitalization, and death.
CDC recommends that everyone 5 years and older protect themselves from COVID-19 by getting fully vaccinated.
CDC recommends that everyone ages 18 years and older should get a booster shot at least two months after their initial J&J/Janssen vaccine or six months after completing their primary COVID-19 vaccination series of Pfizer-BioNTech or Moderna.
People with certain
underlying medical conditions are at increased risk for severe COVID-19 illness, regardless of their age. Severe illness means that the person with COVID-19 may require hospitalization, intensive care, or a ventilator to help them breathe, or that they may even die. Early vaccine access is critical to ensuring the health and safety of this population that is disproportionately affected by COVID-19.
Among adults, the risk for severe illness and death from COVID-19 increases with age, with older adults at highest risk. Early vaccine access is critical to help protect this population that is disproportionately affected by COVID-19.
COVID-19 vaccines help our bodies develop immunity to the virus that causes COVID-19 without us having to get the illness. Different types of vaccines work in different ways to offer protection, but with all types of vaccines, the body is left with a supply of “memory” T-lymphocytes as well as B-lymphocytes that will remember how to fight that virus in the future.
It typically takes a few weeks for the body to produce T-lymphocytes and B-lymphocytes after vaccination. Therefore, it is possible that a person could be infected with the virus that causes COVID-19 just before or just after vaccination and then get sick because the vaccine did not have enough time to provide protection.
Sometimes after vaccination, the process of building immunity can cause symptoms, such as fever. These symptoms are normal and are a sign that the body is building immunity.
The U.S. vaccine safety system ensures that all vaccines are as safe as possible. Learn how federal partners are working together to ensure the safety of COVID-19 vaccines.
CDC has developed a new tool, v-safe, as an additional layer of safety monitoring to increase our ability to rapidly detect any safety issues with COVID-19 vaccines. V-safe is a new smartphone-based, after-vaccination health checker for people who receive COVID-19 vaccines.
Depending on the specific vaccine you get, a second shot 3-4 weeks after your first shot is needed to get the most protection the vaccine has to offer against this serious disease. Learn more about the benefits of getting vaccinated.
Because the current supply of COVID-19 vaccine in the United States is limited, CDC recommends that initial supplies of COVID-19 vaccine be offered to healthcare personnel and long-term care facility residents.
Learn more about who should be vaccinated first when vaccine supplies are limited.
The goal is for everyone to be able to easily get vaccinated against COVID-19 as soon as large enough quantities are available. Once vaccine is widely available, the plan is to have several thousand vaccination providers offering COVID-19 vaccines in doctors’ offices, retail pharmacies, hospitals, and federally qualified health centers.
Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost. However, vaccination providers may be able to charge administration fees for giving the shot. Vaccination providers can get this fee reimbursed by the patient’s public or private insurance company or, for uninsured patients, by the Health Resources and Services Administration’s Provider Relief Fundexternal icon.
The side effects from COVID-19 vaccination may feel like flu and might even affect your ability to do daily activities, but they should go away in a few days. Learn more about what side effects to expect and get helpful tips on how to reduce pain and discomfort after your vaccination.
It’s important for everyone to continue using all the tools available to help stop this pandemic as we learn more about how COVID-19 vaccines work in real-world conditions. Cover your mouth and nose with a mask when around others, stay at least 6 feet away from others, avoid crowds, and wash your hands often.
CDC will continue to update this website as vaccine recommendations and supply change.
COVID-19 vaccines are safe and effective. COVID-19 vaccines were evaluated in tens of thousands of participants in clinical trials. The vaccines met the Food and Drug Administration’s (FDA’s) rigorous scientific standards for safety, effectiveness, and manufacturing quality needed to support emergency use authorization (EUA). The technology behind mRNA vaccines has been in development for over 15 years. Scientists pivoted to apply existing technology to COVID-19 vaccines. Learn more about EUAs in this video.external icon
The Pfizer-BioNTech, Moderna, and Johnson & Johnson’s Janssen COVID-19 vaccines will continue to undergo the most intensive safety monitoring in U.S. history. This monitoring includes using both established and new safety monitoring systems to make sure that COVID-19 vaccines are safe.