Vaccination will be recommended for everyone, but supplies will be limited at first. Federal and state authorities call for health care personnel to be offered vaccine in the first phase of the program, starting with hospital workers, emergency responders and long-term care staff.

The initial priority will be to vaccinate health care personnel who are at high occupational risk for exposure to COVID-19 and those working in roles that are essential to the COVID-19 response. Mayo Clinic expects that the program will expand to all health care personnel soon, as well as patients at high risk of COVID-19 infection and complications.

Mayo Clinic will follow the guidance provided by federal and state authorities to prioritize groups for vaccinations. The guidelines have been developed by numerous national bodies, including the Advisory Committee on Immunization Practices and the National Academies of Science, Engineering and Medicine.

To develop a strategy for equitable allocation of limited vaccine supplies, these guidelines consider the risks of:

• Acquiring infection
• Severe morbidity and mortality
• Negative societal effects
• Transmitting infection to others

As availability improves, vaccines will be offered to all others in accordance to federal and state guidelines.

The safety of COVID-19 vaccine is being closely monitored by the Centers for Disease Control and Prevention. Get more information about the Pfizer, Moderna and Johnson & Johnson vaccines:

Pfizer:

• Pfizer Emergency Use Authorization Fact Sheet
• Pfizer Vaccine Information Statement

Moderna:

• Moderna Emergency Use Authorization Fact Sheet
• Moderna Vaccine Information Statement

Johnson & Johnson:

• Johnson & Johnson COVID-19 Vaccine Information Statement
• Mayo Clinic responds to Johnson & Johnson COVID-19 vaccine pause

On Dec. 12, the Pfizer vaccine received emergency use authorization from the Food and Drug Administration, including authorization to vaccinate pregnant and breastfeeding women. The U.S. Advisory Committee on Immunization Practices recommends with the Pfizer vaccine that these patients discuss vaccination with their health care providers. They should discuss the benefits and risks, and consider what is known and what is not known to make an informed decision with the expectation that many would proceed with vaccination.

Here are resources that may help with your decision:

• I'm pregnant. Should I get the vaccine?
• COVID-19 vaccine advice if you are pregnant or breastfeeding

For the Pfizer vaccine, 60% of people in early-phase studies and in those 55 years and younger experienced some side effects, primarily injection site pain, fatigue and chills. Some people reported headache, muscle pain or joint pain. About 1 out of 5 people got a fever after they received this vaccine. For all people, these symptoms got better without medical care and usually within 24 to 36 hours.

For Moderna, 80% of people in early-phase studies and in those 65 years and younger experienced some side effects, primarily injection site pain, fatigue, chills, headache, muscle pain and joint pain. About 1 out of 7 people got a fever after they received this vaccine. These side effects generally occurred within two days after vaccination and got better in 24 to 48 hours.

The second dose of the Pfizer and Moderna vaccine should still be given even if you had one of these reactions after the first dose.

Outside of health care facilities with critical staffing needs, the management of symptoms, such as fever, differs. Get general guidance for patients. You may continue to work if you feel well enough to, even if you develop a fever, as long as:

• You have ONLY symptoms attributable to vaccine, such as headache, myalgias, chills, fever or local site reactions, AND
• You have NO symptoms of COVID-19 that are not vaccine-attributable, which are cough, shortness of breath, sore throat, or change in sense of taste or smell, AND
• Your symptoms resolve within 72 hours of vaccination, AND
• You have not sustained a significant COVID-19 exposure in the prior 14 days

Vaccine recipients will be provided with guidance on how to interpret side effects and symptoms, and what actions they should take following vaccination.

Although phase 3 trial results are not available, experimental vaccine interim data indicate 90% efficacy after two doses. Efficacy is the measure of effectiveness obtained from a randomized controlled clinical trial. Further details regarding the effectiveness of the vaccine, such as how long the vaccination offers protection, are not yet available.

With the Pfizer/BioNTech vaccine, two doses are given 21 days apart. Most other COVID-19 vaccines that are expected over the next few months are anticipated to be given over two doses 28 days apart.

At this time, Mayo Clinic patients cannot choose which COVID-19 vaccine to receive given unpredictable and limited vaccine allocation. We do not know how much of each vaccine we will receive from week to week and, therefore, cannot make vaccine-specific appointments.

Vaccines are scarce resources, and Mayo Clinic is morally obligated to avoid wasting vaccines.

If we were to permit choice at the time of the vaccination appointment, some vaccine doses would be wasted. Wasted vaccine doses means that fewer people can be vaccinated, which ultimately could lead to more illness and death.

All of the COVID-19 vaccines are safe and effective in preventing severe COVID-19 illness and related hospitalizations, and death. With all vaccines, you may experience some mild side effects, primarily injection site pain, fatigue and chills. These symptoms get better without medical care, usually within 24 to 48 hours.

Mayo Clinic recommends everyone get the COVID-19 vaccine wherever is it available, at Mayo Clinic or elsewhere.

At this time, the Moderna vaccine offers immunity of at least three months. For the other vaccines, it is not yet known how long COVID-19 vaccination will offer protection. Periodic boosters, such as with the annual flu shot, may or may not be needed.

Given the extent of COVID-19 spread in the U.S., masking, social distancing and self-quarantining will not be enough to contain the pandemic. Developing large-scale immunity in the community through vaccination is key to stopping the pandemic.

Everyone will need to continue to take precautions, such as masking and physical distancing, until the spread has stopped. Until then, COVID-19 spread can continue in the community from people who have or don't have symptoms.

A person can be contagious for as many as 14 days without symptoms. A person can develop symptoms but be contagious before symptoms start. Most healthy adults may be able to infect others, beginning two days before symptoms develop and up to 10 days after becoming sick.

Your primary care provider will not offer vaccination for COVID-19 at this time. The COVID-19 vaccine will be available to patients in a phased approach. The vaccination will be available to Mayo Clinic primary care patients at some point in the future, likely at centralized locations.

Yes. Mayo Clinic recommends getting vaccinated for COVID-19, even in those who have had COVID-19 previously. However, those that had COVID-19 should delay vaccination until about 90 days from diagnosis. People should not get vaccinated if in quarantine after exposure or if they have COVID-19 symptoms.

Yes. Mayo Clinic recommends all its staff and patients get the flu vaccine and when it becomes available, the COVID-19 vaccine.

Yes. While the vaccine is highly effective at preventing symptomatic and severe disease, it is not 100% effective, and it is not yet known how well it prevents asymptomatic infection, or how long its effects will last. Everyone will need to continue taking precautions like masking and physical distancing until the spread has stopped.

There are many COVID-19 vaccines in development. The first vaccines Mayo Clinic will receive are not live virus vaccines. Some of the COVID-19 vaccines under development are live but others are not. Those who are pregnant or immunocompromised should not get live vaccines. Mayo Clinic staff will ensure that those who are pregnant or immunocompromised do not get a live vaccine.

Neither the Pfizer/BioNTech COVID-19 vaccine nor the Moderna COVID-19 vaccine contain fetal cells. Fetal cells were not used in the development or production of either vaccine. In two animal studies conducted for the development of the vaccine, researchers performed laboratory testing of the vaccines using historically harvested fetal cell lines. Both of the animal studies were conducted after the vaccine had been developed and was in phase 3 clinical trials at the time of the animal studies.

People with autoimmune diseases can take the vaccines. Some people with autoimmune diseases are taking strong immunosuppressant medications to control their disease. If that’s the case, they become immunocompromised depending on the medication and dose. The vaccine is not contraindicated for immunocompromised people, but might not work as well since their immune system is being suppressed.

The vaccines are not 100% effective but they are far better than not getting vaccine. The benefits certainly outweigh the risks in healthy older persons. One cannot get COVID-19 infection from the initial COVID-19 vaccines Mayo Clinic will receive as they are inactivated vaccines and not live vaccines.

At this time, international patients cannot come to Mayo Clinic just to get vaccinated for COVID-19. Given initial limited supplies, Mayo Clinic is allocated vaccine for patients in its region. Mayo will distribute vaccines to the highest-risk groups based on guidance from public health authorities. As supplies increase in 2021, the program will expand to include more staff and broader patient populations.

Eventually, once there’s enough vaccine, Mayo Clinic will offer the vaccine to all of its patients including its international patients. For now, Mayo Clinic will abide by federal and state guidelines to vaccinate those employees and patients in the highest tiers of risk.

Yes, the COVID-19 vaccine will be free. However, vaccine administration charges will be billed to insurance. We anticipate that the fee for vaccine administration will be covered by the payer at 100% and patients will not be billed for any unpaid charges. Patients and staff will need to bring their insurance card when they receive the vaccine.

The administrative fee covers labor, supplies and administrative support required to set up and operate vaccination clinics, as well as to administer vaccine in a physician office.

As patients become eligible to receive the COVID-19 vaccine, please be aware that persons with a history of severe allergic reaction (e.g., anaphylaxis) to eggs or any other substance should plan to stay to be observed for 30 minutes after vaccination.

If you have patients and/or staff who have a history of severe allergic reaction and they are being vaccinated during work hours, plan for this additional 30 minutes of observation during the work day.

If you are started on the Pfizer/BioNTech or Moderna COVID-19 vaccine, you should receive their second doses of the vaccines, even if you experience side effects after the first dose, except in rare cases of immediate or severe allergic reaction.

Mayo Clinic has established a waiting area at the vaccination site, staffed by medical personnel, in the event a staff member has an allergic reaction.

Neither the Pfizer/BioNTech COVID-19 vaccine nor the Moderna COVID-19 vaccines contain egg nor were eggs used the development or production of either vaccine. However, those with severe allergic reactions to eggs or any other substance (i.e., anaphylaxis) are encouraged to remain after vaccination for 30 minutes for observation.

Yes. Persons who have previously had Guillain-Barre Syndrome may safely receive an mRNA COVID-19 vaccine. These include those from Pfizer-BioNTech or Moderna. To date, no cases of Guillain-Barre syndrome have been reported following vaccination among participants in the mRNA COVID-19 vaccine clinical trials.

If you have a history of an allergic reaction of any severity to polyethylene glycol (PEG) you should not get the Pfizer/BioNTech or the Moderna vaccine.

If you have an allergy to polysorbate, you should get either the Pfizer/BioNTech or the Moderna vaccine.

If you are unsure whether or not you have this allergy, please check with your health care provider.

While there are no formal studies, the best evidence comes from women who got sick with COVID-19 while pregnant. While data clearly indicate pregnant women are at higher risk of hospitalization due to COVID-19 infection, there is no evidence of increased miscarriage rates.

During natural infection, the immune system generates the same antibodies to the spike protein that COVID-19 vaccines would. Thus, if COVID-19 affected fertility, there already would be an increase in miscarriage rates in women infected with COVID-19. This has not happened.

No, COVID-19 vaccines have not been linked to infertility.

A sophisticated disinformation campaign has been circulating online, claiming that antibodies to the spike protein of COVID-19 produced from these vaccines will bind to placental proteins and prevent pregnancy. This disinformation is thought to originate from internet postings by a former scientist known to hold anti-vaccine views. These postings are not scientifically plausible, as COVID-19 infection has not been linked to infertility. Also, no other viral infection or vaccination-inducing immunity by similar mechanisms has been shown to cause infertility. Antibodies to the spike protein have not been linked to infertility after COVID-19 infection. There is no scientific reason to believe this will change after vaccination for COVID-19.

These postings are not scientifically plausible, as COVID-19 infection has not been linked to infertility. Also, no other viral infection or vaccination-inducing immunity by similar mechanisms has been shown to cause infertility. Antibodies to the spike protein have not been linked to infertility after COVID-19 infection. There is no scientific reason to believe this will change after vaccination for COVID-19.

Occupational Safety and Health Administration (OSHA) regulations do not require gloves to be worn when administering vaccinations. Hands will be cleaned with an alcohol-based antiseptic hand rub or washed with soap and water between each patient contact.

Vaccine recipients will be provided with guidance on how to interpret side effects or symptoms and what actions they should take following their vaccination. You may continue to work if you feel well enough to, even if you develop a fever, as long as:

• You have ONLY symptoms attributable to vaccine, such as headache, myalgias, chills, fever, or local site reactions, AND
• You have NO symptoms of COVID-19 that are not vaccine-attributable, which are cough, shortness of breath, sore throat, or change in sense of taste or smell, AND
• Your symptoms resolve within 72 hours of vaccination, AND
• You have not sustained a significant COVID-19 exposure in the prior 14 days

Outside of health care facilities with critical staffing needs, the management of symptoms, such as fever, differs. Get general guidance for patients.

Whether it's vaccine dose one or two, do not take fever reducing-pain medications, such as Tylenol, Feverall, ibuprofen, etc., before vaccination just to prevent reactions that haven't yet happened. Doing so may dampen your immune response. If you do have a moderate headache or body ache as a reaction to the vaccine, you can certainly take such pain relievers as needed to treat that pain.

There is no need to postpone your vaccine until after your surgery. Any side effects, such as fever, that might occur from the vaccine would have resolved within seven days; most side effects resolve within three days. We do not recommend you schedule your vaccine within a few days of your surgery, especially after the second dose of either the Pfizer of Moderna mRNA vaccines. Over 15% of people will experience a fever after the second dose and less than 1% after the first dose.

If you check in on the day of surgery and are found to have a fever, it could result in having to reschedule the surgery. A fever immediately after the surgery raises concerns about a surgical wound infection, so it’s ideal if you can allow a week between the vaccine and surgery, especially for the second dose.

We do not know. The very large pre-licensure trials used symptomatic COVID-19 infection as the outcome to measure. They did not test for asymptomatic COVID-19 infection. We know the COVID-19 mRNA vaccines are 95% effective in preventing symptomatic COVID-19 infection. We do not know yet if they prevent a vaccinated person from getting an asymptomatic infection that the person could spread to another. Those vaccinated must for now still practice the same safety precautions (masking, social distancing, frequent hand-washing) as the unvaccinated.

Providers are getting lots of questions about whether or not it's OK to get the COVID-19 vaccine after having received a different vaccine, like the flu vaccine, and whether it's OK to get another type of vaccine after getting the COVID-19 vaccine and within what timeframe.

Our Mayo Clinic experts suggest you consider delaying getting the COVID-19 vaccine if you've had another type of vaccine within the last 14 days and to wait a couple of weeks after getting the COVID-19 vaccine to receive a different type of vaccine, like the flu vaccine.

While there is no reason to believe that the one vaccine will interfere with the other, when the COVID-19 vaccine was being studied, research volunteers did not receive vaccines at the same time or within two to four weeks of the COVID-19 vaccination. If you had a reaction after vaccination, keeping them separated helps to correctly identify which vaccine may have been responsible.

Mayo Clinic experts have no concerns with either safety or effectiveness of the COVID-19 vaccine for those individuals who choose to proceed with the COVID-19 vaccination despite a recent vaccination.

Yes. Occasional steroid injections do not represent enough steroid to suppress one's immune response to vaccines, including the COVID-19 vaccine.

Because COVID-19 vaccines are distributed at designated locations, at the present time, hospitalized patients cannot receive their second dose of COVID-19 vaccine. Hospitalized patients can reschedule their second dose vaccine.

Yes, do not delay your routine screening or diagnostic mammogram due to a COVID-19 vaccine. Your provider may ask you if you've received the COVID-19 vaccine to document if there is a lymph node in the armpit or neck which can occur as an immune reaction to the vaccine.

Compare the Pfizer/BioNTech, Moderna and Johnson & Johnson vaccines:

All of the vaccines are expected to be protective against the emerging strains. Currently, we have no reason to believe that new strains of COVID-19 will resist the immune response created by vaccination. Furthermore, there is no evidence to indicate available therapies will not continue to be effective. However, Mayo Clinic is closely monitoring the research and clinical observations regarding COVID-19. We are aware of the different mutations, including the UK, South African and California variants. Our researchers are involved in ongoing clinical research to better understand the SARS-CoV-2 virus and variants; as well to identify the best ways to treat COVID-19 infections in all its forms.

The card was created by the CDC to be a helpful reminder and a way to confirm that the correct second dose of the Pfizer or Moderna vaccine is provided to you.

At Mayo Clinic, however, the card is not necessary because Mayo is able to track when you should return and which vaccine you will need for your second dose.

Should you have a need for the information on the card, it will be made available in your patient portal under Immunizations.

Both the Pfizer and Moderna vaccines are given in a two-dose series, either 21 or 28 days apart, respectively. The second dose should be administered as close to the recommended interval as possible. However, if it is not feasible to adhere to the recommended interval, the second dose of Pfizer-BioNTech and Moderna COVID-19 vaccines may be scheduled for administration up to six weeks (42 days) after the first dose. There currently is limited data on efficacy of mRNA COVID-19 vaccines administered beyond this window. If the second dose is administered beyond these intervals, there is no need to restart the series. Completing the second dose maximizes the immune benefits offered through vaccination.

You must delay your COVID-19 vaccination if you the meet any of these conditions:

• You are in quarantine from a recent COVID-19 exposure.
• You are in isolation from a recent COVID-19 infection or a positive COVID-19 test.
• You received convalescent plasma or monoclonal antibody in the last 90 days.

Patients who get a blood test for COVID-19 antibodies after receiving the COVID-19 vaccine may get a negative test result and for good reason. The result depends on the type of antibody test performed. If you get a negative result, this does not mean the COVID-19 vaccine didn't work for you.

There are two types of antibodies that can be detected by lab tests: antibodies to spike (S) or to nucleocapsid (N).

After infection, we produce both S and N antibodies; after vaccination we only make S antibodies.

The primary lab test detects only N antibodies, so it cannot tell us anything about vaccine response. The N antibody test is sometimes used to confirm a recent COVID infection.

If you got vaccinated and then got tested by your provider, you most likely had the N antibody test. We expect that test to be negative, even though you got the vaccine, unless you were recently infected.

S antibody testing after vaccination is not generally recommended. We do not yet know for certain how to interpret this in terms of predicting immunity from vaccination. Immunity comes not only from antibodies but also from "cellular immunity" – the ability of immune cells to attack the virus – which cannot be assessed in common blood tests.

View AME guidance on COVID-19 vaccination and antibody testing.