Everything You Need to Know About the COVID-19 Vaccine

Everything You Need to Know About the COVID-19 Vaccine

By Tollie B. Elliott, Sr., MD, Chief Medical Officer

This blog post is from February 2021. For the latest COVID-19 information, click here.

Dr. Elliott, Chief Medical Officer

After all these months of suffering, we finally have hope with the arrival of the COVID-19 vaccine. I know there is genuine mistrust around vaccines especially among communities of color, and for good reason, but I can tell you with total confidence that it’s safe.

Given the historical injustices in the Black, Hispanic, Native American, and many other ethnic communities, Mary’s Center is committed to listening to all of our participants and engaging you in genuine, earnest conversation.

We have heard your vaccine concerns and would like to take this opportunity to address these very important and life-changing questions.


Which vaccines have been approved?

Currently, two vaccines – Pfizer-BioNTech and Moderna – are authorized in the U.S.

What’s the difference between these vaccines?

Both vaccines are safe and about 95% effective. The main differences between the two are:

  • Pfizer requires colder storage that is usually only available at hospitals
  • The amount of time between doses is 21 days for Pfizer and 28 days for Moderna
  • Pfizer is approved for people 16 and over, and Moderna is approved for 18 and over

How does the vaccine work?

The vaccine helps our bodies develop immunity to the virus that causes COVID-19. The Pfizer and Moderna vaccines are messenger RNA (mRNA) vaccines. Both work by instructing cells in your body to make a protein that triggers an immune response (in the form of antibodies) to protect you when you come into contact with COVID-19. Those antibodies fight off the virus so you are less likely to get very sick from COVID-19.

Is the vaccine effective against the new COVID-19 variants?

Yes, the vaccine will still offer a great level of protection from the COVID-19 variants. Preliminary studies show that the Pfizer and Moderna vaccines are just as effective against the new variant from the U.K., while there may be a slight decrease in effectiveness against the variant from South Africa.


How was the COVID-19 vaccine produced so quickly?

The idea for mRNA vaccines has been around for several years, but until recently, the technology didn’t exist to allow their development to be widespread. Fortunately, through a global effort, technology has caught up and allowed us to create a stable environment for low-cost, rapid development and quick distribution.

“The vaccine that you’re gonna be taking was developed by an African American woman. And that is just a fact! I mean that is a fact!” – Anthony S. Fauci, MD, Director, National Institute of Allergy and Infectious Diseases, National Instititues of Health  

Dr. Fauci has unabashedly given credit to Dr. Kizzmekia Corbett, the 34-year-old African American woman who has contributed mightily to this battle against the COVID-19 pandemic.

Rest assured that scientists and regulators followed every step to guarantee the new vaccine is safe and effective. Several factors made it possible for the process to move quicker than usual:

  • Governments and philanthropists offered unprecedented amounts of funding for the vaccine effort
  • Scientists from around the world shared their research and findings with each other to speed up vaccine development
  • The public showed strong interest in volunteering for vaccine studies
  • A large amount of data on other coronaviruses, such as SARS and MERS, already existed, and scientists have been studying this data for over 50 years
  • The mRNA vaccine is a newer type of vaccine that can be produced faster than older vaccines like those for flu or shingles

How can I trust that the vaccine is safe?

Clinical trials of vaccines must first show they are safe and effective before any vaccine can be authorized or approved for use. Even with the accelerated timeframe for the COVID-19 vaccine, pharmaceutical companies were held to all safety protocols and testing requirements.

Nearly 75,000 people participated in Pfizer and Moderna vaccine studies over the last several months, and reports of adverse events have been remarkably low.

Can the vaccine give me COVID-19?

No, it is impossible to contract COVID-19 from the vaccine because the vaccine doesn’t include the actual virus. If you feel any symptoms after getting vaccinated, those are normal side effects of your body building immunity by creating antibodies.

Will the vaccine change my DNA?

No, mRNA vaccines do not interact with or alter your DNA at all. In fact, your cells will break down and get rid of all mRNA after it serves its purpose of teaching your body to trigger an immune response.

Vaccination Experience

How is the vaccine administered?

The vaccine is given as a shot in your arm near the shoulder, and it takes less than 5 seconds. You will need two doses to complete the vaccination process – three weeks apart for the Pfizer vaccine and four weeks apart for the Moderna vaccine.

Why are there two doses of the vaccine?

The first shot helps your body recognize the virus and gets your immune system ready to fight it, and the second shot boosts that immune response.

You need to get both shots to achieve the full protection of the vaccine. Keep in mind that vaccines take time to reach their potential, so you may not have complete protection until two weeks after your second shot.

Are there side effects of the vaccine?

Side effects are actually a good sign after getting vaccinated – they are proof that your immune system is kicking into gear. As with any vaccine, you may experience pain, redness and swelling at the injection site. Other reactions like fatigue, low-grade fever, chills, headache, and muscle and joint pains are all normal and should subside within 24-72 hours. People have reported more side effects after the second dose than the first.


Can I get the vaccine at Mary’s Center?

In DC, you can go to to determine your eligibility, and you may be able to get the vaccine at Mary’s Center or at another institution by registering online. In Maryland, they also have specific criteria to ensure that the vaccine is prioritized for the most high-risk populations. You can find more information on Maryland’s vaccination efforts here.

Which vaccine is Mary’s Center using?

Community health centers like Mary’s Center are using the Moderna vaccine. Generally, only hospitals have the storage temperature requirements for the Pfizer vaccine.

When will I be able to get the vaccine?

Moderna is producing the vaccine as quickly as they can, but there isn’t enough for everyone yet. Health departments are in charge of distributing the vaccine, and they are prioritizing the people who need it most.

You can see the tiers of priority populations set by DC Health here. We are currently still in the early stages, and the vaccine may not be available for the general public until spring or even summer.

Mary’s Center will help every participant receive the vaccine as soon as we can, and we will publish vaccine distribution plans to our website and social media channels when available.

Why is there no vaccine for children yet?

The first priority was to approve the vaccine for adults because they have a much higher risk of severe illness from COVID-19 compared to children. Children’s immune systems work differently than adults, so they need their own set of vaccine trials before the vaccine is approved for them. Both Pfizer and Moderna are now running vaccine trials for kids 12 and up, and after that they will run trials with younger children.

Will I need to pay for the vaccine?

No, you will not be charged for the vaccine. If you have insurance, it will cover the cost of the vaccine. If you don’t have insurance, your vaccine will be covered by the local or federal government.

Special Circumstances

Should I get the vaccine if I already had COVID-19?

Early evidence suggests that natural immunity from COVID-19 may not last more than 3 months, so you should still get the vaccine. If you are quarantining or isolating because of COVID-19 exposure or diagnosis, wait to get vaccinated until your quarantine has ended and your symptoms have resolved.

What if I had a severe reaction to a previous vaccine?

If you experienced anaphylactic shock from another vaccine, speak to your doctor before receiving the COVID-19 vaccine.

What if I’m pregnant or breastfeeding?

The Centers for Disease Control and Prevention, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine agree that the vaccine should be offered to pregnant and breastfeeding individuals who are eligible for vaccination. You can weigh benefits and risks with your doctor. Speak to your provider for more personalized guidance.

What if I’m immunocompromised or I have an autoimmune disorder?

If you are immunocompromised (e.g., undergoing cancer treatment, HIV positive) or if you have an autoimmune disorder (e.g., lupus, multiple sclerosis), you may still receive the vaccine. Speak to your provider with any further questions.

What’s Next?

Once I get the vaccine, do I still have to take precautions?

While the vaccine is 95% effective, that leaves a small chance that you could still get sick if you’re not careful. Also, we don’t yet know if vaccinated people can transmit the virus to unvaccinated people and make them sick. To fully protect yourself and others, you should continue wearing a mask, practicing social distancing, and washing your hands often.

Dr. Elliott, did you get vaccinated?

I absolutely did, as you can see in the first photo at the top of the page. Aside from a sore arm for less than two days, I feel great. And I look forward to the day when we have enough supply to vaccinate my entire family. I am so very grateful to have the opportunity to do my part in this battle against a deadly disease that is ravaging not only the community that I am from, but the communities I have spent my entire career serving.

“Service to others is the rent you pay for your room here on earth.” – Muhammad Ali

When will life go back to normal?

As more of us get the vaccine, experts will continue to learn about the protection it provides and then they can update their recommendations. Most likely, once the majority of the population is vaccinated, we will be able to return to a more normal way of living.

To find out if you are eligible for the vaccine and to request an appointment through your health department, please access the following resources:

  • Washington, DC: Click here or call 855-363-0333
  • Montgomery County, MD: Click here
  • Prince George’s County, MD: Click here