Vaccinations

The initial allotment of the Pfizer COVID-19 vaccination consisted of a total of 3,900 doses of the vaccine.
Main Content

COVID-19 Vaccination FAQs


Is the mRNA COVID-19 vaccine live?

No, mRNA vaccines do not use the live virus that causes COVID-19.

What are the contents of the mRNA COVID-19 vaccine? Is any microchip nanotechnology inserted into the vaccine?

The vaccine is a white to off-white, sterile, preservative-free, frozen suspension for intramuscular injection. The vaccine contains a nucleoside-modified messenger RNA (mRNA) encoding the viral spike glycoprotein (S) of SARS-CoV-2, the virus that causes COVID-19. The vaccine also includes the following ingredients: lipids, potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate and sucrose. There is no microchip nanotechnology inserted into the vaccine.

How do mRNA vaccines work? Can someone get COVID-19 from the mRNA vaccine?

No, it is not possible to get COVID-19 from the vaccine. After injection, the COVID-19 mRNA vaccines give instructions for our muscle cells to make a piece of what is called the coronavirus “spike” protein. Once the immune system recognizes this protein, it will develop antibodies, like what happens in natural infection against COVID-19. It will not cause COVID-19.

Can mRNA vaccines change a person’s DNA?

No. These mRNA vaccines cause cells to make viral proteins, such as SARS-CoV-2 proteins. When the proteins are made, they are released from the cell; cells from the immune system recognize them as foreign and attack them, generating an immune response. After the spike proteins are generated, the mRNA is naturally degraded by cells. Since mRNA is active only in a cell’s cytoplasm and DNA is located in the nucleus, mRNA vaccines do not interact with DNA. While RNA viruses have a gene to make a protein that allows RNA to be converted to DNA (a process called reverse transcription), mRNA vaccines do not include this gene, so the mRNA cannot convert into DNA and cannot change a person’s DNA.

How is the COVID-19 vaccine administered?  

The Pfizer/BioNTech mRNA COVID-19 vaccine is a two-dose series administered as intramuscular (IM) injections three weeks apart.

What if I missed or cannot receive the second dose of the vaccine on time?

The Advisory Committee on Immunization Practices (ACIP) allows the administration of a second dose within a four-day grace period (e.g., day 17-21). If more than 21 days have passed since the first dose was received, the second dose should be administered as soon as possible. The vaccination series does not need to be restarted.

Will there be a required observation period after vaccination?

Yes, the vaccine recipient will be observed for 15 minutes after receiving a vaccine for any immediate reactions.

Are there any contraindications (conditions or factors that would be a reason to withhold vaccination due to harm) to receiving the vaccine?If I have lots of allergies, is it safe for me to receive the vaccine?

Currently there is no information on absolute contraindications to receiving the vaccine.

Any allergic reactions to the COVID-19 vaccine are likely related to a lipid particle called polyethyelene glycol, which is a known ingredient in other vaccines. For full details on COVID-19 vaccine content, refer to the earlier question about the contents of the COVID-19 vaccine.

A history of an immediate allergic reaction to any other vaccine or injectable therapy (i.e., intramuscular, intravenous, or subcutaneous vaccines or therapies) is not a contraindication to receiving the COVID-19 vaccination. Following administration of the COVID-19 vaccine the observation window is extended to 30 minutes.

It is safe for anyone with mild or non-severe allergic reactions to a vaccine or its products or any injectable medications (intramuscular, intravenous or subcutaneous) to receive the COVID-19 vaccine.

It is considered safe for those who have any severity of allergic reaction to any oral medicine (including the oral equivalent of an injectable medication), food (e.g., peanuts, shellfish), pet, insect, venom, latex or environmental allergens to receive this vaccine.

We recommend those who have a fever or bleeding disorder or are severely immunocompromised or have previously received monoclonal antibody, convalescent plasma or another COVID-19 vaccine as part of a clinical trial tocontact your health care provider or specialist to discuss a safe and appropriate time to receive the COVID-19 vaccine.

Those who are undergoing asymptomatic or symptomatic testing for COVID-19 are advised to await their COVID-19 test results and clearance for return to work before receiving the vaccine.

If I have an immunosuppressive condition, such as HIV, cancer or an organ transplant, or if I am on chemotherapy or taking immunosuppressive medications, is it safe for me to receive the vaccine?

Those with underlying immunosuppressive conditions are at a higher risk for developing severe COVID-19 infection. Data is currently not available to establish the safety and efficacy in these groups.

Profound immunosuppression, such as uncontrolled HIV (low CD4 count, high viral load) or those on active immunosuppressives could potentially not mount an effective antibody response after receiving this vaccination. We recommend that you contact your health care provider or specialist to discuss a safe and appropriate time to receive the COVID-19 vaccine.

These groups may receive the vaccine unless otherwise contraindicated or advised to temporarily defer the vaccine by their health care provider or specialist.

If I have a chronic medical condition such as hypertension, diabetes, COPD or asthma, is it safe for me receive the vaccine?

Those with underlying chronic medical conditions are at higher risk for developing severe COVID-19 infection. Vaccination is encouraged in these groups with underlying medical conditions who have no contraindications to vaccination.

If I have autoimmune disease such as lupus, is it safe for me to receive the vaccine?

Those with underlying autoimmune disease are at higher risk for developing severe COVID-19 infection. Autoimmune disease flares have not been observed during natural COVID-19 infection. The vaccine trial had few participants with autoimmune disease and they did not experience any disease flares after vaccination. Groups with autoimmune disease may receive the vaccine unless otherwise contraindicated. We recommend you contact your health care provider or specialist to discuss a safe and appropriate time to receive the COVID-19 vaccine.

Can pregnant or lactating women receive the vaccine?

Yes. A recent statement from the Society of Maternal Fetal Medicine highly encourages pregnant and lactating women to receive the vaccination as the benefits and potential of avoiding severe COVID-19 disease during pregnancy outweigh any potential adverse events. All involved organizations continue to closely monitor available data on COVID-19 vaccine efficacy and safety to ensure continued appropriateness during pregnancy or breastfeeding. An April study shows Moderna and Pfizer COVID-19 vaccines are safe for pregnant women with no increased risk for miscarriage, premature births and other complications. In fact other studies have shown that transfer of maternal antibodies across the placenta and into breast milk confer passive immunity against SARS-CoV-2 in newborns after maternal vaccination.

What if I am planning to become pregnant in the future? Does the vaccine cause sterility or infertility?

There is NO data or evidence that ANY of the COVID-19 vaccines can cause sterility or infertility. The American College of Obstetricians and Gynecologists (ACOG) states that claims linking COVID-19 vaccines to infertility are unfounded and have no scientific evidence supporting them and the organization strongly recommends everyone receives COVID vaccination, including those planning future pregnancy. Additionally data shows that people who have received any of the three U.S. approved COVID-19 vaccines have not had any increased complications with pregnancy compared to before the pandemic began.

Is it safe to vaccinate children with the mRNA COVID-19 vaccine?

Yes. The Pfizer/BioNtech vaccine trials included age groups 12 and older and it has been approved through emergency use authorization (EUA) for 12 and up.  Data on efficacy and safety of the vaccine in younger pediatric age groups (newborn-11 years of age) is limited at this time but is being studied and is expected to be approved for vaccination of younger children later this year.

What are the short-term side effects of the vaccine?

So far, about 10 percent of vaccinated individuals have experienced side effects in clinical trials. The most common side effects reported after vaccination were injection site pain, headaches, fatigue and new or worsened muscle pain. Fever occurred in a few individuals. The side effects are usually mild and resolve within 1-2 days. You can consider taking over-the-counter medications, such as acetaminophen (Tylenol), for symptom relief.

What are the long-term side effects of the vaccine?

The long-term side effects of the vaccine are unknown. The most common side effects experienced after vaccination have been mild, of short duration and in the first 1-2 days post-vaccination. Serious adverse effects after any vaccination usually occur within six weeks of administration. No serious side effects have been reported within six weeks of the receipt of the COVID-19 mRNA vaccine.

Where do I report any vaccine-related adverse events?

If you have a concern about any vaccine-related adverse events, contact your health care provider. You can report any adverse events to the CDC’s Vaccine Adverse Event Reporting System (VAERS). You can also choose to enroll in the CDC’s V-safe, a voluntary smartphone-based tool, to inform the CDC about any side effects after receiving the COVID-19 vaccine; to receive reminders if you need a second vaccine dose; and to get scheduled check-in messages to monitor your condition.

Do I need to get a COVID-19 test if I develop flu-like symptoms after the vaccination?

About 10 percent of vaccinated individuals will experience side effects similar to flu-like symptoms, such as fever, chills, headaches, body aches, muscle pain and fatigue. We do not anticipate that these symptoms will last long. If you experience chills, headaches, body aches, muscle pain, joint pain or fatigue within 48 hours after receiving the vaccine, these would likely be post-vaccination symptoms rather than symptoms of COVID-19 infection.

If you experience a possible vaccine reaction that may require immediate care, seek care in the closest Emergency Room or call 9-1-1 as appropriate.

If I become exposed to a household contact with COVID-19 before I receive the first dose or between the first and second doses of the vaccination, do I need to undergo COVID-19 testing?

Yes, you should.

If you are scheduled to receive the vaccine but are exposed to a household contact with COVID-19 before receiving the first dose, you are advised to immediately isolate and schedule COVID-19 testing.

Will the COVID-19 vaccine cause false-positive results of COVID-19 PCR or antigen test results?

The Pfizer-BioNTech COVID-19 vaccine is not a live vaccine. Prior receipt of the vaccine will not affect the results of SARS-CoV-2 nucleic acid amplification (RT-PCR) or antigen tests.

Should premedication be given before vaccination?

There are no recommendations to take any specific medication before receiving a vaccination.

How long will it be before a COVID-19 vaccination will take effect?

Based on available data from vaccine clinical trials, it takes a week or two for immunity to develop after completing two doses of the vaccine.

How long will protection last following vaccination?

We do not have complete knowledge of how long protection will last following vaccination. Preliminary results from vaccination clinical trials has shown protection for six months post vaccination. Trials are still ongoing to assess for duration of protection for two years post vaccination. Based on limited data, it appears the immunity generated from vaccination may offer a longer duration of protection than natural infection without risk for COVID-19 disease.

For two-dose vaccines, what happens if I only receive one dose and not both?

It is recommended that you receive both doses of the vaccine to develop a protective immune response. Participants in the vaccine trials who received just one dose of the vaccine had 52-percent protection against COVID-19 compared to those who received both doses, which offered 95-percent protection against COVID-19 disease. Studies have shown a single dose is even less protective against the Delta variant. Everyone needs to be fully vaccinated for full protection.

If the FDA approves another COVID-19 vaccine from a different manufacturer, can I receive doses of COVID-19 vaccinations from different manufacturers?

We strongly recommend you receive both doses of the COVID-19 vaccination from the same manufacturer. If you inadvertently receive doses of vaccine from different manufacturers, you do not need to receive any additional doses from either manufacturer.

If I have already had COVID-19 and recovered, do I still need to receive the COVID-19 vaccine?

Yes, we encourage you to receive a COVID-19 vaccine even if you have already had the infection or have recently recovered from it. Early evidence suggests that natural immunity from COVID-19 may not last very long and re-infection is possible, so we strongly encourage you to get vaccinated. The COVID-19 vaccine will provide a booster immune response and potentially offer a longer duration of immunity. Protection from more transmissible variants also appears to be superior after full vaccination versus natural immunity from prior infection.

I recently had COVID-19 infection. When will it be safe for me to receive the COVID-19 vaccine?

You will be eligible to receive the vaccination after you have completed the recommended duration of isolation and have received clearance to return to work. If you received monoclonal antibody infusion for treatment of COVID-19 disease, you would need to wait for 90-days to receive COVID-19 vaccine.

Can I take the vaccine if I have had convalescent plasma or monoclonal antibody treatments for COVID-19 or have potentially received convalescent plasma or monoclonal antibody treatments for COVID-19 as a part of a clinical trial?

If you have received or have potentially received monoclonal antibody or convalescent plasma as a part of routine care or clinical trial for the treatment of COVID-19 in the previous 90 days, you should not receive the COVID-19 vaccine at this time.

Do I need to repeat vaccine doses if I inadvertently received another vaccine within 14 days of the COVID-19 vaccination?

No, the ACIP does not recommend repeating doses for either vaccine.

If a person is vaccinated against COVID-19, will they still be able to spread the virus to susceptible people?

While it is expected that COVID-19 vaccines may protect against severe infection, they may not necessarily prevent mild or asymptomatic infection. In such cases, a vaccinated person could still spread the virus if he or she is infected. Thus, people will need to continue to use masks and practice social distancing measures after receiving vaccinations for the foreseeable future until herd immunity is established and public health guidance changes.

Why is a COVID-19 vaccine needed if we can do other things to prevent spread, like social distancing and wearing masks?

Currently, we have effective infection prevention measures such as masking, social distancing and hand hygiene in place. The addition of vaccinations will help build immunity against SARS CoV-2, so even if you are exposed to the virus, your body can fight it without the risk for severe disease, hospitalization and death. If a majority (60 to 70 percent) of the population gets vaccinated, it will reduce the spread of the disease and help end the pandemic sooner, with less serious disease and death.

Do I need to wear a mask and avoid close contact with others if I have received both doses of the vaccine?

Yes. Even after you have received the vaccination, it will be important for everyone to continue following infection prevention recommendations like covering your mouth and nose with a mask, wash your hands often and stay at least six feet away from others.

One main reason why:

  • Vaccination does not offer 100 percent immunity. There is still a small risk for you to develop mild or asymptomatic COVID-19 disease after exposure to the virus and you could potentially spread it to others.

Does immunity after getting COVID-19 last longer than protection from COVID-19 vaccines?

We do not have a complete understanding of the duration of protection after COVID-19 infection compared to vaccination. The protection someone gains from having an infection (called natural immunity) varies depending on the disease, and it varies from person to person. There have been cases of reinfection in those with a history of previous COVID-19 infection, suggesting natural immunity may not last very long. A few studies have reported a potentially short duration of immunity in those who had mild or asymptomatic infection. Based on available data from vaccine studies, vaccination-induced immunity lasts for at least six months and researchers are continuing to study how much longer it may last.

Is it possible to distinguish between antibodies generated from natural immunity and COVID-19 vaccine-induced immunity?

Natural immunity after COVID-19 infection results in the development of antibodies against various proteins of SARS CoV-2 virus, such as nucleocapsid protein and spike protein. Antibodies generated from COVID-19 vaccination are directed specifically against the coronavirus spike protein, which prevents the virus from attaching and entering into a cell. You can distinguish antibodies generated from natural COVID-19 infection versus vaccination by testing for antibodies directed against other viral proteins (e.g., nucleocapsid) which are detected with natural infection alone.

What percentage of the population needs to get vaccinated to have herd immunity to COVID-19?

Herd immunity is a term used to describe when enough people have protection, either from previous infection or vaccination, so that it is unlikely a virus can continue to spread and cause disease. As a result, everyone within the community is protected, even if some people don’t have any individual protection themselves. Experts have suggested a large portion of the population (60-70 percent) should have protection to establish herd immunity. If we were to rely on natural infections to control COVID-19, an estimated 1 million to 5.4 million people would die on the way to developing herd immunity. Vaccination will help us establish herd immunity and safely end this pandemic with less disease and death.

What is the new COVID-19 strain? Will vaccines work against it?

There are ongoing reports of newly recognized coronavirus strains, including Alpha (from UK) and Delta (from India). In scientific terms, this is referred to a genetic variant. Some variants carry mutations including one in the coronavirus spike protein that the virus uses to bind to its receptor in human cells. It is very important to point out that viruses mutate all the time and that is expected to occur during a pandemic. While we are still gathering information on how these variants are different from the original “wild type” virus, we do know that the Alpha was about 50% more transmissible, and that the Delta is over twice as transmissible. All three of the vaccines approved for use in the U.S. are effective against these variants, however it appears their efficacy may be slightly reduced. The one we know the most about at this point is the Pfizer vaccine, whose efficacy against the Delta variant appears to be reduced from about 95% to around 88%. The best strategy to stop the coronavirus from mutating and developing new variants is by slowing down the transmission of this virus. Ongoing prevention practices such as hand washing, social distancing, wearing a mask around others, and avoiding social gatherings will help slow the transmission of COVID-19.

Should I get COVID-19 vaccine if I had a history of Guillain-Barré Syndrome (GBS) after a prior non-COVID vaccination?

Yes, we encourage you to receive the COVID-19 vaccine. There does appear to be a slightly increased risk of GBS with the Johnson & Johnson vaccine, however, there is no data suggesting an association between GBS and COVID-19 vaccination among participants in both the Pfizer/BioNTech and Moderna vaccine trials. There are ongoing investigations to study a potential link between COVID-19 and GBS based on case reports.

Is there any risk for Bell's palsy after COVID-19 vaccination?

Currently, there is no evidence for increased occurrence of Bell's palsy after COVID-19 vaccination than in the general public. In the Pfizer/ BioNTech vaccine trial, Bell’s palsy was reported by four vaccine participants and none in the placebo group. All four cases had complete recovery. The observed frequency of reported Bell’s palsy in the vaccine group was consistent with the expected background rate in the general population. Currently, the Pfizer/BioNTech vaccine has been administered to over 1 million people with no documented cases of Bell's palsy. The FDA and CDC continue to closely monitor for any cases of Bell’s palsy post COVID-19 vaccination through the Vaccine Adverse Events Reporting System (VAERS).

Do we have to receive COVID-19 vaccination every year?

Currently, we do not have any data suggesting the need for vaccination on an annual basis against COVID-19 as is the case for flu vaccination. The coronavirus differs from the flu virus in many ways and does not change its structure as rapidly as flu. We know the COVID-19 vaccines remain effective for 6-8 months and counting at this point, and hopefully will offer even longer protection against COVID-19.

Updated interim guidance from CDC allows for millions of Americans who are at highest risk for COVID-19 to receive a Pfizer-BioNTech COVID-19 booster shot to help increase their protection. More information can be found here - External site.

Can COVID-19 vaccine and other vaccines be given simultaneously?

Yes, CDC no longer recommends waiting for 14-days in between COVID-19 vaccine and other vaccines.

Can I get a COVID-19 booster vaccination? 

COVID-19 booster vaccine is currently being offered for certain high-risk groups with immunocompromising conditions and others that meet select criteria. 

A summary of MSDH updated COVID-19 vaccine booster recommendations can be found here (PDF).

Am I still considered "fully vaccinated" if I don't get a booster shot? 

Yes. Booster vaccination is optional and not mandatory. Everyone is still considered fully vaccinated two weeks after their second dose of 2-shot series, such as mRNA vaccines, or two weeks after a single-dose vaccine, such as J&J/Janssen vaccine.