COVID-19 Frequently Asked Questions (FAQs)

COVID-19 Vaccines

What COVID-19 vaccines are currently available?

In the United States, three vaccines are currently available. They fall into two categories: mRNA and viral vector vaccines.

The mRNA vaccines that are currently available include the Pfizer-BioNTech vaccine and the Moderna vaccine.

The viral vector vaccine that is currently available is the Janssen/Johnson & Johnson vaccine. It is available to people 18 years old and older and is administered in only one dose. To learn more about the Janssen/Johnson & Johnson vaccine, see:

It is recommended that you get whatever vaccine is available to you.

Several other vaccines are currently being studied in clinical trials. You can read updates on vaccine approvals from the U.S. Food and Drug Administration (FDA) here:

You can also learn more about the vaccine candidates that are being studied and track which vaccines have been approved in the U.S. and around the world here:

(Last Updated: 5/25/21)

Where can I learn more about how COVID-19 vaccines work?

You can learn more about how COVID-19 vaccines work from the Centers for Disease Control and Prevention (CDC).

To learn more about how mRNA vaccines work, see:

To learn more about how viral vector vaccines work, see:

(Last Updated: 3/2/21)

Will COVID-19 vaccines change my DNA?

No, COVID-19 vaccines will not change your body’s DNA. The vaccines that are currently available will trigger your cells to produce a piece (the viral spike protein) of SARS-CoV-2 (the virus that causes COVID-19), which will in turn trigger your immune system to produce antibodies for SARS-CoV-2. The vaccines do not affect or interact with the DNA that makes you who you are as a person, or the DNA that is passed on to future children. Additionally, in relation to mRNA vaccines, mRNA cannot combine with DNA. mRNA is very fragile and will fall apart within 72 hours.

(Last Updated: 3/2/21)

The Pfizer-BioNTech and Moderna vaccines sound very similar. Are they interchangeable? If I receive a dose of one type of vaccine first, can my second follow up dose be the other type of vaccine?

While some researchers have begun to study this, we do not yet know if the Pfizer-BioNTech and Moderna vaccines are interchangeable. Until we have research studies and data that say otherwise, YOU MUST receive the same vaccine twice. For example, you must receive two doses of the Pfizer-BioNTech vaccine OR two doses of the Moderna vaccine.

(Last Updated: 1/11/21)

If I am getting an mRNA vaccine, can I delay getting my second shot?

You should do your best to get your second shot on the date that you were scheduled to receive it, or as close to that date as possible. This is because the scientific evidence that is currently available indicates that the high level of effectiveness provided by mRNA vaccines is achieved when this vaccine schedule is followed. If delays arise, consult with your usual medical provider or do your best to speak to a medical professional at the site that administered your first dose to re-schedule your second dose as soon as possible.

(Last Updated: 3/2/21)

What are the side effects of COVID-19 vaccines?

As reported by the FDA, common reactions to the vaccines include: site pain, fatigue, headache, muscle pain, chills, joint pain, fever, injection site swelling, and injection site redness. These symptoms indicate that your immune system is responding to the vaccine.

An information sheet from the FDA on the Pfizer-BioNTech vaccine is available here:

An information sheet from the FDA on the Moderna vaccine is available here:

An information sheet from the FDA on the Jannsen/Johnson & Johnson vaccine is available here:

A recent study released on February 12, 2021 by the CDC examined the frequency of severe allergic reactions after individuals received either the Pfizer-BioNTech or Moderna vaccine. From December 14, 2020 through January 18, 2021:

  • For individuals receiving the Pfizer-BioNTech vaccine, among 9,943,247 doses administered, 47 cases of severe allergic reactions were found (a rate of 4.7 cases per million doses administered).
  • For individuals receiving the Moderna vaccine, among 7,581,429 doses administered, 19 cases of severe allergic reactions were found (a rate of 2.5 cases per million doses administered).

This data tells us that severe allergic reactions to the vaccine are extremely rare. (You can read the study here:

The CDC has set up the v-safe smartphone app that you can use to let them know if you are experiencing any side effects after you receive the vaccination. According to the CDC, “V-safe is a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after you receive a COVID-19 vaccination. Through v-safe, you can quickly tell CDC if you have any side effects after getting the COVID-19 vaccine. Depending on your answers, someone from CDC may call to check on you and get more information. And v-safe will remind you to get your second COVID-19 vaccine dose if you need one.” You can learn more about the v-safe app here:

Additionally, the U.S. Department of Health and Human Services has set up a system for healthcare providers to report severe adverse events related to COVID-19 vaccines through the Vaccine Adverse Event Reporting System. This is a surveillance system that enables researchers to keep a careful eye on how frequently serious side effects of the COVID-19 vaccines are occurring. You can learn more about that system here:

(Last Updated: 3/2/21)

I have heard that some people who were getting the Johnson & Johnson vaccine experienced serious problems with blood clotting. Can you give me more information about this?

Yes, use of the of Johnson & Johnson’s Janssen (J&J/Janssen) was temporarily paused to investigate these reports, but the CDC and FDA has recommended that use of the J&J/Janssen COVID-19 Vaccine resume in the United States effective April 23, 2021. However, women younger than 50 years old especially should be aware of the rare risk of blood clots with low platelets after vaccination, and that other COVID-19 vaccines (Pfizer & Moderna) are available where this risk has not been seen. This adverse event is rare, occurring at a rate of about 7 per 1 million vaccinated women between 18 and 49 years old. For women 50 years and older and men of all ages, this adverse event is even more rare. You can read the FDA & CDC’s statement on the Johnson & Johnson vaccine here:

For three weeks after receiving the vaccine, you should be on the lookout for possible symptoms of a blood clot with low platelets. These include:
• Severe or persistent headaches or blurred vision
• Shortness of breath
• Chest pain
• Leg swelling
• Persistent abdominal pain
• Easy bruising or tiny blood spots under the skin beyond the injection site
Seek medical care right away if you develop one or more of these symptoms. You can read more information about the Johnson & Johnson vaccine here:
(Last Updated: 5/25/21)

Who is eligible to get a COVID-19 vaccine in Florida?

Currently, individuals 12 and older are eligible to get a COVID-19 vaccine in Florida.

You can follow COVID-19 vaccine updates from the Florida Department of Health here:

(Last Updated: 7/29/21)

Where can I find information about where COVID-19 vaccines are available?

If you are eligible to receive a vaccine, you can learn more about where you can get a COVID-19 vaccine by visiting the following websites:

You can also text your zip code to 438829, or call 1-800-232-0233 (TTY 888-720-7489).

Information specific to Miami-Dade County can be found by visiting the Miami-Dade County COVID-19 Vaccine webpage here:

You can also find information from the Miami-Dade office of the Florida Department of Health:

(Last Updated: 3/12/21)

Where can I sign up to be notified when the COVID-19 vaccine becomes available to me?

You can sign up to be notified when a COVID-19 vaccine is available to you and pre-register for the vaccine here:

(Last Updated: 3/2/21)

Once you get the COVID-19 vaccine, is wearing a mask and avoiding close contact with others still necessary?

Once you get the COVID-19 vaccine, you should still wear masks indoors and in crowded outdoor settings, especially if you live in an area with a high level of COVID-19 cases (currently, the entire state of Florida is experiencing high levels of COVID-19).

This is because of the new variant of SARS-CoV-2 (the virus that causes COVID-19), called the Delta variant. The Delta variant can be spread more easily than the original virus. If you are vaccinated, your risk of getting the Delta variant (or being hospitalized or dying from the Delta variant) is much lower compared to individuals who are not vaccinated. However, there is still a chance vaccinated individuals can get the Delta variant (no vaccine is 100% effective), and vaccinated individuals who do get the Delta variant can pass it on to others. This is why it is important that you continue wearing masks, which help to stop the spread of COVID-19 and the Delta variant.

If you have unvaccinated people (such as children) or people with weakened immune systems in your household, we recommend that you continue to take extra precautions to protect them (by wearing masks, staying 6 feet apart from people you don’t live with, and avoiding crowds and poorly ventilated indoor spaces). Vaccinated immunocompromised individuals should also take extra precautions.

It is also very important that you continue to follow all guidelines required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance. Additional guidance from the CDC is available here:

(Last Updated: 7/31/21)

What activities can I do once I get the COVID-19 vaccine?

According to the CDC, individuals are considered fully vaccinated for COVID-19 two weeks after they have received the second dose of the Pfizer-BioNTech or Moderna vaccines, or two weeks after they have received the Janssen/Johnson & Johnson vaccine. The CDC has issued guidance for activities fully vaccinated individuals can do along with precautions they should continue to take. This guidance can found here:

(Last Updated: 3/12/21)

What is known about SARS-CoV-2 variants and their impact on current vaccine effectiveness?

Viruses must infect hosts (humans) to survive, and they are constantly changing and evolving to more efficiently infect hosts (because this improves viruses’ chances of survival). When viruses evolve, variants are produced. SARS-CoV-2, the virus that causes COVID-19, is also evolving. Scientists are carefully monitoring SARS-CoV-2 variants because they may spread more easily from person to person, make people more sick, or reduce the effectiveness of vaccines.

Currently, the variant that is having the most severe impacts on the spread of COVID-19 in our communities is the Delta variant. The Delta variant spreads much more easily from person to person than the original SARS-CoV-2 virus (in some situations, the Delta variant is as contagious as the chicken pox). It spreads especially quickly among unvaccinated individuals. Early research suggests that the Delta variant may lower the effectiveness of vaccines. However, vaccinated individuals are still much less likely to get the Delta variant, and if they do get the Delta variant, early research suggests their risk of hospitalization and death is 25 times lower than that of unvaccinated individuals. However, If they do get the Delta variant, vaccinated individuals can pass it on to others, which is why it is important vaccinated individuals continue to wear masks in indoor and crowded outdoor settings.

It is important to understand: the more SARS-CoV-2 spreads, the more opportunities it will have to mutate into more dangerous variants. The COVID-19 vaccine is the most effective tool we have to prevent the spread and mutation of SARS-CoV-2 in our communities because it breaks cycles of transmission. The more people that get the vaccine, the fewer people will get sick with COVID-19, which reduces the number of opportunities SARS-CoV-2 has to mutate.

You can read more about what is currently known about SARS-CoV-2 variants from the CDC here:

(Last Updated: 7/31/21)

I have additional questions about the COVID-19 vaccine that aren’t covered here. Where can I find more information?

More information is available from the Centers for Disease Control and Prevention (CDC) here:

This website has answers to questions related to:

  • How long protection from a COVID-19 vaccine lasts
  • Getting the COVID-19 vaccine if you are pregnant
  • Getting the COVID-19 vaccine if you have underlying conditions

(Last Updated: 3/2/21)

General COVID-19 Information

What is Coronavirus?

The SARS-CoV-2 virus is the name of the specific coronavirus that is causing our current COVID-19 pandemic; coronavirus disease 2019 (COVID-19) is the name of the illness it causes. SARS-CoV-2 is an RNA virus and is one of several hundred different coronaviruses. Only a handful of coronaviruses cause human disease, mostly mild respiratory disease. The SARS CoV-2 virus is one of three coronaviruses that causes a severe respiratory infection. The other two viruses are the SARS-CoV (severe acute respiratory syndrome) virus and the MERS (Middle East respiratory syndrome) virus.

The most common symptoms of COVID-19 are fever, fatigue, cough, sore through, muscle aches, shortness of breath, and loss of taste or smell. Some people may have loss of appetite, nausea, and diarrhea. Some individuals become extremely ill when they get sick with COVID-19, leading to hospitalization in intensive care units and even death. Many people do not have any symptoms. These people, however, are still infectious and can pass the virus on to others who may have severe symptoms.

(Last Updated: 11/17/2020)

How risky is COVID-19?

About 2 out of every 100 people diagnosed with COVID-19 in the United States has died of COVID-19 compared with about 1 out of 1000 that we normally see with influenza.

The older you are the greater the risk of hospitalization and deaths.  Compared to an 18-29 year-old, a 50 year old has a 4 times higher risk of hospitalizations and a 30 times greater risk of death.  A 75 year-old has an 8 times higher risk of hospitalization and 220 times higher risk of death.  On the other hand a 5-17 year old has a 9 times lower risk of hospitalization and 16 times lower risk of death (CDC: However, children are being hospitalized with COVID-19 and children have died from COVID-19. It is just that their risk is lower. Risk is also higher for people who have diabetes, heart disease, lung disease, and obesity. Some people who have mild symptoms in the beginning will become very sick in the second week. Shortness of breath or chest pain are signs of serious problems. People with shortness of breath or chest pain should seek medical care immediately.

(Last Updated: 11/17/2020)

How is SARS-CoV-2 spread?

The virus is spread mostly through respiratory droplets when people cough, sneeze, speak, or sing. Most of the particles drop within 6 feet of a person which is why 6 feet of physical distancing is recommended. It is also why masks should be worn anytime you are within 6 feet of another person that you don’t live with.

While it is possible that there is some airborne (longer distance spread), this spread seems to be rare. The virus can also be spread through contamination of objects when people cough, sneeze, or speak onto objects or contaminate them with their hands.  This contamination may last for several days, but this mode of transmission does not seem to be as important as by respiratory droplets. Nevertheless, it is highly recommended that people wash their hands or use hand sanitizer regularly so that if their hands do become contaminated, they can clean them before touching their eyes, nose or mouth and infecting themselves.

A person can be infectious with COVID-19 up to 2 days before their symptoms begin and 10 days after their symptoms begin. People infected with COVID-19 who do not have symptoms are also infectious. It is thought that almost half of all infections are caused by people either before they have symptoms or by people with no or mild symptoms. People tend to be most infectious early in their infection.

(Last Updated: 11/17/2020)

How long is someone with COVID-19 infectious?

A person can be infectious with COVID-19 up to 2 days before their symptoms begin and 10 days after their symptoms begin. People infected with COVID-19 who do not have symptoms are also infectious. People tend to be most infectious early in their infection.

(Last Updated: 11/17/2020)

How is COVID-19 diagnosed?

COVID-19 is diagnosed with a viral test from a swab of the mouth, nose, or throat. The most common test is a real time polymerase chain reaction test (RT-PCR). This is the most sensitive test. It detects the presence of SARS-CoV-2 genetic material. The rapid antigen test is not as sensitive. It is more likely to miss infection, but it gives results faster. The rapid antigen test detects COVID-19 proteins. An antibody test from blood tests for past infection. They are not usually positive until at least 2 weeks after symptoms start. More information about types of testing is available in this short video from the Federal Drug Administration (FDA):

(Last Updated: 3/2/21)

What causes false positive or false negative COVID-19 tests?

No laboratory test is perfect.  All laboratory tests will miss at least some infections, or falsely be positive when a person does not have an infection.

A false positive test means that an individual tests positive for SARS-CoV-2 (or the material the body produces in response to it) when they do not in fact have SARS-CoV-2. This may occur due to human or lab error: for example, an individuals’ sample may be accidentally contaminated when it is collected.

A false negative test means that an individual tests negative for SARS-CoV-2 when they do in fact have SARS-CoV-2. This may occur if an insufficient sample was collected. It may also occur if the individual was tested early on in their infection and their body has not yet produced enough of the virus for the test to detect its genetic material or the other types of materials SARS-CoV-2 triggers the body to produce (for example, antigens). This is why the time someone who might have been exposed to the virus should stay away from others (also known as the quarantine period) is 14 days–it can take anywhere from 2-14 days for the type of material that tests are looking for to increase enough to be detected.

A number of medical companies have produced tests that may use different scientific methods for detecting material produced by SARS-CoV-2 in the body. Therefore, each type of test has different rates of false positive or false negative results. For more information about the types of tests that are currently approved by the FDA, see:

(Last Updated: 3/15/21)

How is COVID-19 treated?

It depends on how sick people are.  If they have mild illness, they need to stay home and isolate themselves.  If they are severely ill, they will need to be hospitalized and some will need to be put on a ventilator. You can learn more the potential treatments for COVID-19 from the CDC here:

(Last Updated: 3/15/2021)

What does “herd immunity” mean?

Herd immunity is when there are enough people in a community with immunity to COVID-19 that would prevent a person infectious with COVID-19 from transmitting it to anyone around them because everyone around them would be immune. We do not know what proportion of the population would need to be immune to have herd immunity in the case of COVID-19. It is likely to be 70% or higher.

(Last Updated: 3/15/2021)

What are the long-term effects of coronavirus infection?

Some people, even those who had mild illness, end up with symptoms lasting months.  The most frequent of these symptoms are fatigue, shortness of breath, cough, joint pain and chest pain. Some people also have difficulty thinking and concentrating (people have called this “brain fog”), depression, muscle pain, headache, fever, and heart palpitations. Less commonly people have had series long-term problems with their heart (inflammation of the heart muscle), lung function, kidney damage, hair loss, loss of smell and taste, memory problems, and depression and anxiety. We do not know yet how long lasting these problems will be. More information can be found at:

(Last Updated: 11/17/2020)

How common are these long-term complications?

We are still learning, but one study of hospitalized patients in Italy found that more than 85% had symptoms 2 months after their infection began. In a telephone survey of people who were not hospitalized, 35% of symptomatic participants were still not back to their normal state of health 2 weeks or more after testing (26% 1-34 years, 32 35-49 year olds and 47% 50 and older). A study of 26 competitive college athletes who were diagnosed with COVID-19, did not require hospitalization and most did not have symptoms but 12 (46%) had evidence of myocarditis on magnetic resonance imaging. (Source: Del Rio C, Collins LF, Malani P. Long-term Health Consequences of COVID-19. JAMA. 2020 Oct 5.

(Last Updated: 11/17/2020)

What are COVID-19 “Long Haulers”?

Individuals experiencing long-term impacts of COVID-19, also known as COVID-19 “Long Haulers,” have been identified. These are individuals who have had COVID-19, but are taking longer than expected to recover, with symptoms lasting weeks to months after initially getting COVID-19. Such symptoms include fatigue, shortness of breath, cough, joint pain, and chest pain.

The Centers for Disease Control and Prevention note that it is “actively working to learn more about the whole range of short- and long-term health effects associated with COVID-19. As the pandemic unfolds, we are learning that many organs besides the lungs are affected by COVID-19 and there are many ways the infection can affect someone’s health.”

For more information about the long-term effects of COVID-19, see:

(Last Updated: 2/16/21)

Can children get and spread COVID-19?

Yes. Although fewer children have become sick with COVID-19 compared to adults, they can get and spread COVID-19. More information is available here:

(Last Updated: 3/2/21)

What is multisystem inflammatory syndrome?

Multisystem inflammatory syndrome is a serious illness in children that is associated with SARS-CoV-2. It occurs in children with and without symptoms of COVID 19 several weeks after the COVID-19 illness. It involves several organ systems including the digestive system, the heart and blood vessels, blood skin and respiratory system. Most children with it need intensive care. (Source: Feldstein LR, et al.  Multisystem Inflammatory Syndrome in U.S. Children and Adolescents. N Engl J Med. 2020 Jul 23;383(4):334-346.)

Additional information is available at:

(Last Updated: 11/17/2020)

Where can I find information about the numbers of COVID-19 in Miami-Dade County and the United States?

County reports are available from the Florida Department of Health. To access them, go to and then click on See County Report. You can then go to the pages for Dade County.

Additional information about Miami-Dade County can be found at the Moving to a New Normal Dashboard, which is available here:

Researchers at FIU have also created a website to track COVID-19 data in Miami-Dade County that is available here:

You can access national data from the CDC at

(Last Updated: 3/12/21)

How do we know how much COVID-19 transmission is occurring in the community?

The Florida Department of Health is monitoring COVID-19 transmission through several different ways. One way is called syndromic surveillance which involves measuring the number of people with COVID-19 symptoms that are presenting to emergency departments each day. Another way is the number of people who are being reported positive for the first time with COVID-19 each day. Also, the percentage of people testing positive who test positive out of all people testing is also monitored each day. Additionally, data about the number of people being hospitalized for COVID-19, the number of people in intensive care bed and the number of people on ventilators is monitored each day. This information helps us know how much severe illness there is and also if hospitals are running out of capacity or not.  All of these pieces of information are important to understand where we are and what we need to do to prevent the spread of COVID-19 in our community.

(Last Updated: 11/17/2020)

I have heard something about COVID-19, but I’m not sure if it’s true. Where can I learn more about myths and facts related to COVID-19 and the COVID-19 vaccine?

There are many myths out there about COVID-19 and COVID-19 vaccines. Sometimes it can be hard to separate myth from fact. If you would like to learn more, we recommend the following resources:

CDC, Myths and Facts about COVID-19 Vaccines:

Mayo Clinic, COVID-19 Myths Debunked:

Mayo Clinic, COVID-19 Vaccine Myths Debunked:

(Last Updated: 3/15/2021)

Preventing the Spread of COVID-19

How do we prevent the transmission of SARS-CoV-2 virus?

The most important thing you can do to prevent transmission is to get vaccinated.

Because almost half of transmissions seem to be due to people who do not have symptoms or only have mild symptoms, you need to assume that everyone around you potentially is infectious. Therefore, you should:

  • Wear a mask both indoors and outdoors when you are within 6 feet of another person that you do not live with
  • Wash your hands or use hand sanitizer regularly
  • Stay home if you feel ill
  • Say 6 feet away from people that you do not live with at all times
  • Do not attend any large gatherings, especially indoor gatherings.

To help remember what to do, remember the 3 W’s:

  • Wear your mask
  • Wash your hands
  • Watch your distance

(Last Updated: 5/25/21)

What other things can I do to protect myself and others?

Get the flu shot so that you do not need to see a doctor or be hospitalized for flu. The flu shot prevents influenza. Even in cases where it does not prevent influenza, it prevents serious influenza cases and hospitalizations.

(Last Updated: 11/17/20)

What is contact tracing?

Contact tracing is what the health department does to prevent COVID-19. Here is how it works: All laboratories are required by law to report all COVID-19 tests to the health department. If someone has a positive test, a health department professional will call that person and interview them to find out when the person was likely to be infectious and who the close contacts of that person were during the infectious period.

The infectious period is two days before the symptoms began until 10 days after the symptom started. A close contact is anyone who was within 6 feet of a person for a total of 15 minutes until the time the person is isolated. The contact tracer will then contact the close contacts and tell them that they need to quarantine at home for 14 days from the last time they had close contact with the person who has COVID-19. The health department will not tell any of the close contacts who the person with COVID-19 infection is. That information is kept confidential.

Contact tracing is a very important way to control COVID-19 because so much transmission happens before a person even has symptoms. If people are quarantined during that high-risk period, then they can’t infect anyone else and that chain of infection is stopped. Therefore, it is very important that people with COVID-19 infection work with the health department staff to provide the names of all close contacts. Otherwise the infections just keep continuing.

The Florida Department of Health urges all Floridians to answer calls from (833) 917-2880, (833) 443-5364 and (850) 583-2419 as this is part of Florida’s comprehensive contact tracing effort. More information about contact tracing in Florida can be found at:

(Last Updated: 11/17/20)

What is the difference between quarantine and isolation?

According to the CDC:

(Last Updated: 3/2/21)

If you are exposed to someone with COVID-19 after you are fully vaccinated, do you still need to quarantine?

According to CDC guidance as of 2/10/21, vaccinated persons with an exposure to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria:

  • Are fully vaccinated (i.e., ≥2 weeks following receipt of the second dose in a 2-dose series, or ≥2 weeks following receipt of one dose of a single-dose vaccine)
  • Are within 3 months following receipt of the last dose in the series
  • Have remained asymptomatic since the current COVID-19 exposure

Persons who do not meet all 3 of the above criteria should continue to follow current quarantine guidance after exposure to someone with suspected or confirmed COVID-19.

More information is available here:

(Last Updated: 3/2/21)

If you test positive for COVID-19 after you are fully vaccinated, do you still need to isolate for 10 days?

Yes. Although vaccines are very effective, it can take a few weeks after you receive the vaccine to develop enough antibodies to protect against illness. Even after this time period, there is still a small chance you can get COVID-19. If this happens, follow all isolation guidelines and consult a healthcare professional.

It is also important to note that getting the COVID-19 vaccine will not result in a positive COVID-19 test. If you test positive after becoming fully vaccinated, it is important to assume you have the virus and to take all precautions to protect yourself, your family, and others.

(Last Updated: 3/2/21)

5 COVID-19 Vaccine Myths Debunked

From: 5 Covid-19 vaccine myths debunked (FIU News Article)


MYTH: Researchers rushed to develop the COVID-19 vaccine, so it’s not safe.

FACT:  Although COVID-19 vaccines were developed in record time, that does not mean they are not safe. All the vaccines that are currently available in the United States went through full safety testing, including Phase III clinical trials, which are the strongest study designs we have to test new medical treatments in humans. In Phase III clinical trials, tens of thousands of volunteers received either the vaccine or placebo injection (think of a placebo as a dummy vaccine, made of saltwater). These thousands of volunteers were then monitored for months to see if the group that received the vaccine had a higher proportion of serious adverse reactions compared to the group that received the placebo. The Phase III clinical trials showed that COVID-19 vaccines were very safe and greatly reduced COVID-19 infections, hospitalizations and deaths.

Also, the mRNA technology that was used in the Moderna and Pfizer/BioNTech vaccines had been in development for years, long before we knew what COVID-19 was. Additionally, in the U.S., we have a very robust vaccine safety monitoring system, which allows health officials to take swift action if serious adverse reactions occur. If you receive the COVID-19 vaccine and experience an adverse reaction, you can report it here:

You can also report side effects here:

For more information on mRNA technology, you can view an interview on the National Institute of Health Facebook page with Dr. Kizzmekia Corbett, one of the scientists who worked on the vaccines, here:

You can read more about the U.S. vaccine safety monitoring here:

MYTH: The COVID-19 vaccine can affect a women’s ability to have children.

FACT: There is no evidence that the COVID-19 vaccine affects fertility, in women or men. Often, myths around the COVID-19 vaccine start like a game of telephone, where one person passes an incomplete piece of information onto another person, and then that person tells the next person a piece of what they think they heard, and so on. With social media, sometimes these games of telephone go viral, and that is what has happened with this myth.

Early on, some scientists raised theoretical concerns that the proteins involved with the COVID-19 vaccine response might be similar to those involved with pregnancy, and so the COVID-19 vaccine might interfere with pregnancy. However, there is no evidence that this is true. Millions of women have received the COVID-19 vaccine, and there has been no data to show that it negatively affects fertility or pregnancy. The American College of Obstetricians and Gynecologists (ACOG) notes that “claims linking COVID-19 vaccines to infertility are unfounded and have no scientific evidence supporting them” and “recommends vaccination for all eligible people who may consider future pregnancy.” ACOG also “recommends that pregnant individuals have access to COVID-19 vaccines.”

You can read the ACOG guidance on the COVID-19 vaccine here:

You can read more from the CDC about COVID-19 vaccines while pregnant or breastfeeding here:


MYTH: If you already had COVID-19, you don’t need to get the vaccine.

FACT: If you already had COVID-19, you should still get the vaccine. It is true that if you recover from getting sick with COVID-19, your body will produce antibodies that offer some level of protection against getting COVID-19 again in the future. However, researchers are still studying how long these antibodies may last. From what we know so far, this protection doesn’t seem to last very long. This is why getting vaccinated if you’ve already had COVID-19 is still very important. The COVID-19 vaccine triggers a very strong immune response. This means that if you get the COVID-19 vaccine, your immune system will likely have the antibodies and tools it needs to fight COVID-19 for a longer time compared to if you get sick with COVID-19. There is also evidence that the COVID-19 vaccine offers stronger protection against variants of SARS-CoV-2 (the virus that causes COVID-19).

Individuals who have COVID-19 should wait until they are fully recovered before getting the vaccine, so that they do not risk giving COVID-19 to others.

MYTH: Getting the COVID-19 vaccine means you are completely immune and can’t get infected.

FACT: While getting the COVID-19 vaccine greatly reduces your risk of becoming infected with SARS-CoV-2 (the virus that causes COVID-19), it is important to remember that no vaccine is 100 percent effective. There is still a small chance that you can get COVID-19. If you are vaccinated but have unvaccinated individuals (such as children) or immunocompromised people living in your household, you should still take precautions to protect yourself and your household, such as wearing a mask indoors or avoiding crowded spaces. Vaccinated immunocompromised individuals should also take extra precautions.

You can read more about how well the COVID-19 vaccines work here:

MYTH: Because the long-term side effects of the COVID-19 vaccine are still being studied, it is safer not to get the COVID-19 vaccine.

FACT:  Although researchers are still studying the long-term side effects of the COVID-19 vaccine (so far, significant longer-term side effects have not been observed), this does not mean that it is safer to avoid getting the COVID-19 vaccine until these studies have been completed. We know for sure that a significant proportion of people who have had COVID-19 experience long-term health conditions, even after they have recovered from their initial infection, and even if they are young or initially did not experience any symptoms. Known as “Long COVID,” long-term impacts of COVID-19 may include fatigue, difficulty breathing, chest pain, joint or muscle pain, and depression or anxiety. We are still learning more about Long COVID but getting the COVID-19 vaccine greatly reduces the risk of getting COVID-19, which in turn reduces one’s risk of experiencing long-term chronic conditions such as Long COVID.

It is important that each individual consider their own risks and benefits when deciding whether to get the COVID-19 vaccine, but it is also important to remember that getting COVID-19 has the potential to become a serious chronic health condition.

You can read more about Long COVID here:


Skip to content