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Be a Hero! Understand the COVID-19 Vaccine

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Publication Number: M2387

Vaccines are the safest and most effective measures we have against infectious diseases. Think about some of the world’s most devastating diseases, like smallpox, measles, and polio. Today, we are protected from these diseases by vaccines.

In fact, these vaccines have been successful for such a long time that you may not even know anyone who has had the diseases they prevent. That’s the long-term goal of any vaccination program: to put diseases out of sight and out of mind.

It’s natural to have questions and concerns about the COVID-19 vaccine. In this publication, we hope to give you the answers you need, based on science.

It’s important to understand the science behind the vaccine, so that you can protect yourself and everyone you care about from COVID-19.


Why did the vaccine get approved so quickly?

The vaccine was developed and approved so quickly for four basic reasons:

  • Medical science has become so advanced that scientists around the world could quickly apply and share some of the newest techniques to create a vaccine that would work. We can do things now in months that used to take years.
  • In the past, the steps or stages of vaccine development had to happen one after the other. In developing the COVID-19 vaccine, some of the later steps could happen at the same time, so that the overall process was much shorter.
  • The U.S. government provided funding to some companies to help with the costs of developing the vaccine.
  • The companies developing the vaccine were able to provide extremely convincing data about the effectiveness of the vaccine.

Was the development and approval process for the vaccine too fast to be safe?

While the process happened very quickly, none of the steps were skipped. The vaccines were tested in tens of thousands of people, and the data on safety and effectiveness were very carefully reviewed by scientists working for the vaccine companies, the federal government, and other agencies.

How does the vaccine work?

Like any other vaccine, this vaccine contains ingredients that make the cells in your body react just as they would to the real virus. This reaction is your immune response. That means that, if you should be exposed to the actual virus in the future, your cells will recognize it and defeat it, so you won’t get sick.

Will I catch COVID-19 from the vaccine?

No. The versions of the vaccine from Pfizer and Moderna do not contain the virus. They contain just a part of the virus, its “messenger RNA,” which is just enough to cause the cells in your body to develop immunity. The AstraZeneca vaccine contains proteins from the virus, but not the entire virus.

Is the vaccine safe for me to take?

Yes! The vaccine has been through extensive trials that have shown that it is very safe. In fact, it has been through the same rigorous trials as other vaccines we routinely take. Findings from these trials show that there is a very small chance the vaccine could cause a reaction in very few people within an hour of receiving the shot, but that those reactions are likely to be mild and not life-threatening.

If you are not sure whether the vaccine is right for you, talk to your doctor or other health care provider.

Will the vaccine change my DNA?

No. The vaccine will not change anyone’s DNA. DNA is located in the nucleus of your cells, and the vaccines work on parts of the cells outside of the nucleus. So they never get near the DNA in your cells.

Does the vaccine contain microscopic robots?

No. You may have heard some versions of the vaccine described as using “nanotechnology,” but that doesn’t mean robots. The Pfizer vaccine, for example, uses very tiny fat particles, called “nanoglobules,” to carry the messenger RNA into your cells. “Nano” just means very small.

Does the vaccine contain things that will allow people to track my movements?

No. The vaccine does not have anything other than the active ingredients, which have been shown to have up to 95% effectiveness in preventing COVID-19.


When can I get the vaccine?

The vaccine will be administered in phases. For up-to-date information on scheduling, check the Mississippi State Department of Health website at

Pay attention to reliable news outlets, your local health department, and other trusted sources of information to know when it is available for you.

Where can I get the vaccine?

You should get your vaccination only from your doctor, a hospital or clinic, a licensed pharmacy, or a site set up by one of these trusted sources. Do not respond to emails, phone calls, or online ads from people or organizations you don’t know who are trying to sell or send you a vaccine. There will be no do-it-yourself versions of the vaccine.

To find out more about where you can get the vaccine, check the Mississippi State Department of Health website at

How much will the vaccination cost?

It shouldn’t cost you anything. The federal government has paid for all the doses that will be distributed in the U.S. If someone tries to charge you money for the vaccine, that may be a sign they are not a distributor you can trust. However, your doctor’s office or clinic may charge you for an office visit.

You should not be asked to pay for an appointment or to get on a “priority list” to receive the vaccine. Don’t trust phone calls, emails, or online ads that try to get you to pay to get on a list for the vaccine. Don’t share any of your personal information with people you don’t know.

There is more than one company producing a vaccine. What are the differences?

The Pfizer and Moderna vaccines both use messenger RNA, which travels to your cells and makes proteins from the coronavirus. Those proteins cause an immune response, which basically “teaches” your body how to fight the virus. This means that, if you encounter the virus again, you’ll be able to fight it off.

AstraZeneca’s approach is more like a traditional vaccine. Part of the protein from the virus itself is injected into your body, causing your immune system to build up a response to protect you if you are exposed to the real virus in the future.

In the end, they do the same thing—they help your body develop immunity to the virus. They just work in different ways. All three of these vaccines require two doses to be fully effective.

Will I know which vaccine I’m getting?

Yes. You will receive a card with information about the vaccine you received, which will include the manufacturer.

If I already had COVID-19, do I still need to get the vaccination?

Yes! It is possible to get COVID-19 more than once. The second infection can cause illness that is just as bad as or even worse than your first infection.

Also, some of the vaccine research has shown that the vaccine produces a stronger and more lasting immune response than was seen in people who had actually had COVID-19.

If I get a vaccination, will that information be shared with other people and businesses?

Your private health information may not be shared with others. The information will be documented in your health record.

If I get a vaccination, what can I expect?

After getting your vaccination, you may feel pain at the site of the shot. You might also feel tired or have a headache, and your lymph nodes might swell. You might even have a fever. This does not mean you’re getting COVID-19. Instead, it means that your immune system is doing what it is supposed to do and developing a response to fight off the disease. These symptoms should last only a day or two.

Some people have had allergic reactions shortly after receiving the vaccine. These people were known to have severe allergies to other substances. If you have severe allergies, talk to your doctor before getting the vaccine.

If I get a vaccination, what should I do?

Pay attention to how you’re feeling. If you have a severe allergic reaction that causes swelling in your face or neck or difficulty breathing, go to the emergency room. If you feel sick, stay home if you can. If your symptoms last for more than 2 days, check with your doctor.

After your first dose of the vaccine, be sure to return to receive your second dose at the right place and time.

If I get a vaccination, will I still need to wear a mask and socially distance?

Yes! For the foreseeable future, we will still need to wear masks and socially distance. Scientists are still working to understand what percentage of the population has to be vaccinated before we can reach “herd immunity.” Herd immunity means that so many people in our population will be immune that the virus will have no place to go, and its impact will become very small. Only then will we be able to leave some of these solid prevention measures behind.

How can I help?

Trust the science and get the vaccine! Let your family and friends know you have received the vaccine and encourage them to get it, too!

Make sure you have the most current and most accurate information about the vaccine and its availability. Check the Mississippi State Department of Health website at And check trusted local media outlets, your local health department, and your local health care providers.


The information given here is for educational purposes only. References to commercial products, trade names, or suppliers are made with the understanding that no endorsement is implied and that no discrimination against other products or suppliers is intended.

M2387 (POD-01-21)

By David Buys, PhD, MSPH, CPH, Extension State Health Specialist, and Elizabeth Gregory North, Head, Agricultural Communications.

Copyright 2021 by Mississippi State University. All rights reserved. This publication may be copied and distributed without alteration for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.

Produced by Agricultural Communications.

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Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. GARY B. JACKSON, Director

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Portrait of Dr. David Buys
Associate Professor
State Health Specialist
Portrait of Ms. Elizabeth Powell Gregory North
Head, Ag Communications

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