Frequently Asked Questions about COVID-19 Vaccination

The protection someone gains from having an infection (called “natural immunity”) varies depending on the disease, and it varies from person to person. Because this virus is new, we don’t know how long natural immunity might last. Current evidence suggests that getting the virus again (reinfection) is uncommon in the 90 days after the first infection with the virus that causes COVID-19.

We won’t know how long immunity lasts after vaccination until we have more data on how well COVID-19 vaccines work in real-world conditions.

Experts are working to learn more about both natural immunity and vaccine-induced immunity. CDC will keep the public informed as new evidence becomes available.

Experts do not yet know what percentage of people would need to get vaccinated to achieve herd immunity to COVID-19. Herd immunity means that enough people in a community are protected from getting a disease because they’ve already had the disease or they’ve been vaccinated. Herd immunity makes it hard for the disease to spread from person to person, and it even protects those who cannot be vaccinated, like newborns. The percentage of people who need to have protection in order to achieve herd immunity varies by disease. CDC and other experts are studying herd immunity and will provide more information as it is available.

The two COVID-19 vaccines currently available in the United States do not contain eggs, preservatives, or latex. For a full list of ingredients, please see each vaccine’s Fact Sheet for Recipients and Caregivers:

• Pfizer-BioNTech COVID-19 vaccineexternal icon
• Moderna COVID-19 vaccineexternal icon

Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost. However, vaccination providers can charge an administration fee for giving someone the shot. Vaccination providers can be reimbursed for this by the patient’s public or private insurance company or, for uninsured patients, by the Health Resources and Services Administration’s Provider Relief Fund. No one can be denied a vaccine if they are unable to pay the vaccine administration fee.

When the Food and Drug Administration authorizes or approves a new COVID-19 vaccine, the Advisory Committee on Immunization Practices (ACIP) quickly holds a public meeting to vote on whether to recommend the vaccine. Based on input from ACIP, CDC then publishes vaccine recommendations in the Morbidity and Mortality Weekly Report.

ACIP and CDC are also making recommendations for who should be offered COVID-19 vaccine first when supplies are limited. While CDC makes recommendations for who should be offered COVID-19 vaccine first, each state has its own plan for vaccine prioritization, distribution, and allocation. Please contact your state health department for more information on its plan for COVID-19 vaccination.

Learn more about how CDC is making COVID-19 vaccine recommendations.

Because the supply of COVID-19 vaccine in the United States is currently limited, CDC is providing recommendations to federal, state, and local governments about who should be vaccinated first. CDC’s recommendations are based on those of the Advisory Committee on Immunization Practices (ACIP), an independent panel of medical and public health experts.

Each state has its own plan for deciding which groups of people will be vaccinated first. You can contact your state health department for more information on its plan for COVID-19 vaccination.

The goal is for everyone to be able to get a COVID-19 vaccination easily as soon as large quantities of vaccine are available. As the vaccine supply increases, more groups will be added to receive vaccination. Learn more about CDC recommendations for who should get vaccinated first.

To protect yourself, follow these recommendations:

• Wear a mask over your nose and mouth
• Stay at least 6 feet away from others
• Avoid crowds
• Avoid poorly ventilated spaces
• Wash your hands often

Get more information about these and other steps you can take to protect yourself and others from COVID-19.

Yes. Due to the severe health risks associated with COVID-19 and the fact that reinfection with COVID-19 is possible, you should be vaccinated regardless of whether you already had COVID-19 infection. If you were treated for COVID-19 symptoms with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.

Experts do not yet know how long someone is protected from getting sick again after recovering from COVID-19. The immunity someone gains from having an infection, called “natural immunity,” varies from person to person.  It is rare for someone who has had COVID-19 to get infected again. It also is uncommon for people who do get COVID-19 again to get it within 90 days of when they recovered from their first infection.  We won’t know how long immunity produced by vaccination lasts until we have more data on how well the vaccines work.

Both natural immunity and vaccine-induced immunity are important aspects of COVID-19 that experts are working to learn more about, and CDC will keep the public informed as new evidence becomes available.

The federal government does not mandate (require) vaccination for individuals. For some healthcare workers or essential employees, a state or local government or employer, for example, may require or mandate that workers be vaccinated as a matter of state or other law. Check with your employer to see if they have any rules that apply to you.

Yes. Not enough information is currently available to say if or when CDC will stop recommending that people wear masks and avoid close contact with others to help prevent the spread of the virus that causes COVID-19.

Experts need to understand more about the protection that COVID-19 vaccines provide in real-world conditions before making that decision. Other factors, including how many people get vaccinated and how the virus is spreading in communities, will also affect this decision. We also don’t yet know whether getting a COVID-19 vaccine will prevent you from spreading the virus that causes COVID-19 to other people, even if you don’t get sick yourself. CDC will continue to update this page as we learn more.

While experts learn more about the protection that COVID-19 vaccines provide under real-life conditions, it will be important for everyone to continue using all the tools available to help stop this pandemic.

To protect yourself and others, follow these recommendations:

• Wear a mask over your nose and mouth
• Stay at least 6 feet away from others
• Avoid crowds
• Avoid poorly ventilated spaces
• Wash your hands often

Together, COVID-19 vaccination and following CDC’s recommendations for how to protect yourself and others will offer the best protection from getting and spreading COVID-19.

The currently authorized vaccines to prevent COVID-19 in the United States require 2 shots to get the most protection:

• Pfizer-BioNTech doses should be given 3 weeks (21 days) apart
• Moderna doses should be given 1 month (28 days) apart

You should get your second shot as close to the recommended 3-week or 1-month interval as possible. However, there is no maximum interval between the first and second doses for either vaccine. You should not get the second dose earlier than the recommended interval.

Additional COVID-19 vaccines are in Phase 3 clinical trials. Learn more about the different COVID-19 vaccines.

Wait at least 14 days before getting any other vaccine, including a flu or shingles vaccine, if you get your COVID-19 vaccine first,. And if you get another vaccine first, wait at least 14 days before getting your COVID-19 vaccine.

If a COVID-19 vaccine is inadvertently given within 14 days of another vaccine, you do not need to restart the COVID-19 vaccine series; you should still complete the series on schedule. When more data are available on the safety and effectiveness of COVID-19 vaccines administered simultaneously with other vaccines, CDC may update this recommendation. this recommendation may be updated.

Manufacturing very large quantities of vaccine takes time. The goal is for everyone to be able to easily get a COVID-19 vaccine when large quantities are available for distribution.

CDC and the Advisory Committee on Immunization Practices have published recommendations for which groups should be vaccinated first to help guide decisions about how to distribute limited initial supplies of COVID-19 vaccine.

CDC makes recommendations for who should be offered COVID-19 vaccine first, and each state has its own plan to prioritize, distribute, and allocate vaccine. Learn more about how CDC makes vaccine recommendations.  As more vaccines are authorized for use in the United States and the supply of vaccines increases, several thousand vaccination locations will be available, such as doctors’ offices, retail pharmacies, hospitals, and federally qualified health centers.  Please contact your state health department for more information on its plan for COVID-19 vaccination.

To protect yourself and others, follow these recommendations:

• Wear a mask over your nose and mouth
• Stay at least 6 feet away from others
• Avoid crowds
• Avoid poorly ventilated spaces
• Wash your hands often

Get more information about these and other steps you can take to protect yourself and others from COVID-19.

The federal government oversees a centralized system to order, distribute, and track COVID-19 vaccines. All vaccines are ordered through CDC. Vaccination providers receive vaccines from CDC’s centralized distributor or directly from a vaccine manufacturer.

Two vaccines are authorized and recommended to prevent COVID-19 in the United States. Other COVID-19 vaccine candidates are in development, and clinical trials are being conducted at the same time as large-scale manufacturing.

The implementation of COVID-19 vaccine distribution involved detailed planning focusing on every step of the process including:

• Establishing and testing logistical plans with manufacturers and commercial partners that are part of CDC’s centralized COVID-19 vaccine delivery system
• Coordinating the distribution of vaccines and needed supplies from centralized locations
• Developing processes for ordering additional doses of the vaccine after the first supply has been shipped
• Receiving, storing, and handling vaccines properly at very specific temperatures
• Deciding who should receive a vaccine first, based on national recommendations, if there are not enough doses of the vaccine for everyone
• Giving the vaccines safely during an ongoing pandemic
• Reporting on vaccine inventory, administration, and safety using a variety of new and enhanced data systems
• Expanding safety surveillance through new systems and additional information sources, as well as scaling up existing safety monitoring systems
• Developing plans to assess vaccine effectiveness, which means how well the vaccines protect against COVID-19 under real-life conditions
• Making sure the public, healthcare providers, state and local health departments and others receive timely, credible, clear communication about all aspects of the vaccination program

A safe and effective COVID-19 vaccine is a critical component of the U.S. strategy to reduce COVID-19-related illnesses, hospitalizations, and deaths. The U.S. government’s goal is to have enough COVID-19 vaccine doses for all people in the United States who choose to be vaccinated.

State, tribal, territorial, and local jurisdictions: CDC worked with state, tribal, territorial, and local jurisdictions on the development of COVID-19 vaccination plans for their respective areas. CDC released a playbook on September 16, 2020, to provide specific information to consider during vaccination plan development. The playbook is updated periodically to provide jurisdictions with the latest information.

Private partners and federal agencies: CDC has worked with private partners, such as chains and networks of independent pharmacies, and other federal agencies (e.g., the Indian Health Service) on plans for wider distribution of COVID-19 vaccines. For example, CDC is working with pharmacies to offer on-site COVID-19 vaccination services for residents in long-term care settings, such skilled nursing facilities, nursing homes, and assisted living facilities, where most residents are over 65 years of age.

CDC is working with partners across the country to make sure people have the information they need to make informed decisions and be confident in deciding to get vaccinated. CDC’s key priorities are:

• Regularly sharing clear and accurate information with people to make sure they understand the risks and benefits of getting vaccinated and can make informed decisions
• Helping healthcare personnel feel confident in their decision to get a COVID-19 vaccine
• Helping healthcare providers answer their patients’ questions about the vaccine
• Engaging communities and individuals equitably and inclusively to ensure that people have opportunities to ask questions and get clear, accurate information about COVID-19 vaccines

Easy access to COVID-19 vaccines is critically important. That’s why CDC is working with public health, healthcare providers, and other partners to make sure people can easily get a COVID-19 vaccine and that cost is not a barrier. Learn more about CDC’s Vaccinate with Confidence strategic framework pdf icon[144 KB, 1 page] for COVID-19 vaccines.

All the COVID-19 vaccines being used have gone through rigorous studies to ensure they are as safe as possible. Systems that allow CDC to watch for safety issues are in place across the entire country.

The U.S. Food and Drug Administration (FDA) has granted Emergency Use Authorizations for COVID-19 vaccines that have been shown to meet rigorous safety criteria and be effective as determined by data from the manufacturers and findings from large clinical trials. Watch a video describing the emergency use authorization. Clinical trials for all vaccines must first show they meet rigorous criteria for safety and effectiveness before any vaccine, including COVID-19 vaccines, can be authorized or approved for use. The known and potential benefits of a COVID-19 vaccine must outweigh the known and potential risks of the vaccine. Learn more about how federal partners are ensuring the safety of COVID-19 vaccines in the United States.

People  who are pregnant and part of a group recommended to receive the COVID-19 vaccine may choose to be vaccinated. If you have questions about getting vaccinated, talking with a healthcare provider may might help you make an informed decision. While breastfeeding is an important consideration, it is rarely a safety concern with vaccines.

No data are available yet on the safety of COVID-19 vaccines in lactating women or on the effects of mRNA vaccines on breastfed infants or on milk production/excretion. mRNA vaccines are not thought to be a risk to breastfeeding infants. People who are breastfeeding and are part of a group recommended to receive a COVID-19 vaccine, such as healthcare personnel, may choose to be vaccinated.

To make sure that more information is gathered regarding the safety of these vaccines when administered during pregnancy, pregnant people are encouraged to enroll in v-safe, CDC’s new smartphone-based tool being used to check-in on people’s health after they receive a COVID-19 vaccine. If pregnant people report health events through v-safe after vaccination, someone from CDC may call to check on them and get more information. Additionally, pregnant people enrolled in v-safe will be contacted by CDC and asked to participate in a pregnancy registry that will monitor them through pregnancy and the first 3 months of infancy. Learn more about COVID-19 vaccination considerations for people who are pregnant or breastfeedingexternal icon.

People with underlying medical conditions can receive the FDA-authorized COVID-19 vaccines provided they have not had an immediate or severe allergic reaction to a COVID-19 vaccine or to any of the ingredients in the vaccine. Learn more about vaccination considerations for persons with underlying medical conditions. Vaccination is an important consideration for adults of any age with certain underlying medical conditions because they are at increased risk for severe illness from the virus that causes COVID-19.

Serious problems from vaccination can happen, but they are rare. CDC has learned of reports that some people have experienced severe allergic reactions—also known as anaphylaxis—after getting a COVID-19 vaccine. As an example, an allergic reaction is considered severe when a person needs to be treated with epinephrine or EpiPen^© or if they must go to the hospital. Learn more about COVID-19 vaccines and allergies.

​If you get a COVID-19 vaccine and you think you might be having a severe allergic reaction after leaving the vaccination site, seek immediate medical care by calling 911.

You can report side effects and reactions using either v-safe or the Vaccine Adverse Event Reporting System (VAERS.)

• V-safe is a new smartphone-based, after-vaccination health checker for people who receive COVID-19 vaccines. V-safe uses text messaging and web surveys from CDC to check in with vaccine recipients following COVID-19 vaccination. V-safe also provides second vaccine dose reminders if needed, and telephone follow up to anyone who reports medically significant (important) adverse events.
• Vaccine Adverse Event Reporting System (VAERS)external icon is the national system that collects reports from healthcare professionals, vaccine manufacturers, and the public of adverse events that happen after vaccination; reports of adverse events that are unexpected, appear to happen more often than expected, or have unusual patterns are followed up with specific studies. Reports to VAERS help CDC monitor the safety of vaccines. If experts detect an unexpected adverse event, they quickly study it further to assess whether it is a true safety concern. Experts then decide whether changes are needed in U.S. vaccine recommendations. This monitoring is critical to help ensure that the benefits continue to outweigh the risks for people who receive vaccines.

Healthcare providers will be required to report certain adverse events following vaccination to VAERS. Healthcare providers also have to adhere to any revised safety reporting requirements according to FDA’s conditions of authorized use throughout the duration of any Emergency Use Authorization; these requirements would be posted on FDA’s websiteexternal icon.

You can expect normal side effects after you are vaccinated. Refer to What to Expect at Your Appointment to Get Vaccinated for COVID-19 for additional information.