COVID-19 Resource Center

COVID-19 Vaccine Frequently Asked Questions

 Why should I get the COVID-19 vaccine?
Because you have decided that the benefits of preventing a COVID-19 infection outweigh any risks of the vaccine. The vaccine may help protect you from getting COVID-19 and is considered a safe way to build protection against the disease. COVID-19 can have serious, life-threatening complications, and there is no way to know how COVID-19 will affect you or your loved ones. If you still get infected, the vaccine may prevent serious illness and death. The vaccine may also protect your family and community.
 Which vaccine should I take?
 There are currently two vaccines available in the U.S. – Pfizer-BioNTech and Moderna. It is recommended that you take whichever vaccine is available to you. All U.S. COVID-19 vaccines have passed the same rigorous review process, and all are highly effective at preventing hospitalizations and deaths from COVID-19. You may wish to consider your specific circumstances if more than one vaccine choice is available – check with your doctor.
 For the two-shot vaccines, when do I get the second dose?
The timing between your first and second shot depends on which vaccine you received. You should have your second shot as close to the recommended 3-week or 1-month interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not receive the second dose earlier than the recommended interval.
 Can the vaccine give me COVID-19?
No. None of the COVID-19 vaccines authorized for use in the U.S. use the live virus that causes COVID-19.
 Will I test positive once I get the COVID-19 vaccine?
No. Viral tests used to diagnose COVID-19 check samples from the respiratory system for the presence of the virus that causes COVID-19. Since the vaccines do not contain the live virus, they will not affect your test result. However, it typically takes a few weeks for the body to build immunity after vaccination. Therefore, it is possible to test positive if you were infected with the virus that causes COVID-19 just before or just after vaccination or if your test was a false positive. There is also a possibility you may test positive on some antibody tests if your body develops an immune response. Antibody tests indicate you had a previous infection and that you may have some level of protection against the virus. Experts are currently researching how COVID-19 vaccination may affect antibody testing results. 
 Should I get vaccinated if I already had COVID-19?
Yes. Experts do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible—although rare—that you could be infected with the virus that causes COVID-19 again within 90 days. The vaccine is believed to provide protection with the benefit found in the clinical trials. However, you should not receive the vaccine while you are actively infected, but after full recovery (usually 14 days after symptom onset and clearance to end your isolation). Also, if you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine.
 If I am pregnant, can I get the COVID-19 vaccine?
Yes. There is currently no evidence that antibodies formed from COVID-19 vaccination cause any problem with pregnancy, including the development of the placenta. Also, people who are trying to become pregnant now or who plan to try in the future may receive the COVID-19 vaccine. There is no evidence that fertility problems are a side effect of any vaccine, including COVID-19 vaccines.
 Are there any side effects from the COVID-19 vaccine?
 Yes. As with many vaccines, there may be mild side effects (pain/swelling in the arm where you received the shot, fever, chills, fatigue, and headache). These are normal signs that your body is building protection. Side effects should only last a few days. It is important that you return for your second dose (if receiving the Pfizer or Moderna vaccine), even if the first dose caused mild side effects. Rarely, do more severe side effects occur.
 If I have side effects from COVID-19 vaccination, can I return to my workplace?
You should be able to return to your workplace after receiving the vaccine. Most people who get the vaccine have few or no side effects. For those who have side effects, they are usually mild, but may affect the ability to do some daily activities. If you experience a fever after vaccination, you may need to stay home from work pending further evaluation.
 Are there long-term side effects from the COVID-19 vaccine?
It will take more time and more people receiving the vaccine to learn about very rare or possible long-term side effects. However, at least 8-weeks of safety data were collected in the clinical trials for all the authorized vaccines. It is unusual for vaccine side effects to appear more than 8 weeks after vaccination. Vaccines do not generally have long-term side effects and there is no reason to believe the COVID-19 vaccine will be an exception. Systems are in place at the U.S. Centers for Disease Control and Prevention (CDC) to monitor for safety issues across the country.
 Should I take Tylenol or Motrin before my vaccine dose?
 No. Do not take medications before receiving the vaccine. Taking over-the-counter medications such as aspirin, acetaminophen (e.g., Tylenol) and ibuprofen (e.g., Motrin, Advil) before receiving a vaccine reduces the vaccine’s ability to work and can blunt your immune response to the vaccine.
 How much will it cost for me to get the vaccine?
Nothing – it’s free! The federal government is providing the vaccine free of charge to ALL people living in the U.S. whether or not they are citizens. Providers can be reimbursed for vaccine administration fees 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.
 Will I receive documentation of my vaccine/a vaccine card?
When you receive your COVID-19 vaccination, you will be given a vaccine card as documentation. The card will contain your name and birthdate, vaccine manufacturer and lot number, as well as, where the vaccine was administered and the date the vaccine was given to you. It is important to hold onto this card because it may serve several important purposes in the future. It is recommended to take a picture or scan of the card and keep the original in a safe place.
 Will I be required to get vaccinated for work?
It depends. The federal government does not mandate vaccination for individuals. However, for certain essential employees, a state, local government, or employer 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.
 Is the vaccine safe since it was developed so quickly?
Yes. The U.S. Food and Drug Administration (FDA) approves a vaccine for use only if there is enough data to suggest that it is safe and effective; this is after clinical trials have been conducted with thousands of people of various ages, races, and ethnicities and when its benefits outweigh any risks. Every study and every phase of every trial was carefully reviewed and approved by a safety board and the FDA. The process was transparent and rigorous, with continual oversight and expert approval. The FDA will continue to monitor and oversee vaccine production to ensure all safety protocols are followed. The FDA and CDC also collect and analyze information from reports of any side effects that may occur after a vaccine has been licensed. CDC developed a smartphone-based tool, v-safe, to identify any safety issues with COVID-19 vaccines. Download the v-safe app after you are vaccinated.
 Will the COVID-19 vaccine alter my DNA?
No. COVID-19 mRNA or viral vector vaccines do not affect or interact with your DNA in any way. The mRNA from a COVID-19 vaccine never enters the nucleus of the cell, which is where our DNA is kept. After being used to produce the spike protein, your body gets rid of the mRNA within a few days. Likewise, the genetic material delivered by the viral vector does not integrate into your DNA.
 How long will vaccine immunity last?
Because this is a new virus with new vaccines to combat it, the length of immunity after developing COVID-19 or getting the vaccine is unknown. Experts are working to learn more about both natural immunity and vaccine-induced immunity.
 Do I still need to wear a mask and practice physical distancing after receiving the vaccine?
Yes. Vaccines are a critical tool to ending the spread of the COVID-19 virus, but they will not immediately eliminate all risk. Until enough people have been vaccinated to stop the spread of the virus, it is important to continue to take precautions in public places like wearing a mask, physical distancing, avoiding crowds and poorly ventilated spaces and frequently washing your hands until we know more.
For additional questions, consult with your health care provider.

Last updated April 14, 2021