March 19, 2021

The Coronavirus Pandemic – Answering Your Questions

Coronavirus virion

Students may have questions related to the coronavirus pandemic or you may be teaching about it. This page provides information about some of the questions that have been pressing during the course of the pandemic. If you would like to see other questions addressed, you can email questions to To see the archive of questions from 2020, please visit the Archived Coronavirus Pandemic Questions page. We also have a dedicated page on the VEC website. Go to for even more information.

March 18  

What can teens expect when getting a COVID-19 vaccine? 

Are you excited to get a COVID-19 vaccine? Maybe a bit nervous? People have different feelings about getting vaccines — and individuals even sometimes have different feelings about different vaccines. An array of feelings is normal, but sometimes it helps knowing what to expect. 

Teen vaccine eligibility
As of this writing, three COVID-19 vaccines are approved for use in the United States:

  • Pfizer-BioNTech 
  • Moderna
  • Johnson & Johnson/Janssen 

Of these, only the Pfizer vaccine can be given to teens ages 16 and older. The other two vaccines are approved for ages 18 and older. This means currently only some teens are eligible for a COVID-19 vaccine. However, clinical trials are underway for younger teens and children. 

When will vaccines be available for all teens? 
Clinical trials for teens ages 12 to 17 have been fully recruited and are almost finished. These trials are helping to determine if the vaccines being used in adults will also be safe and work well in younger people. Hopefully, the findings from these studies will be available during the summer of 2021 allowing for use in this group soon thereafter. 

Companies will likely also soon start clinical trials in children as young as 6 months of age.

Preparing to get the vaccine
Most immunization sites require appointments though some may have “walk-in” hours for eligible people to get vaccinated. This varies widely from state to state, so you should check how things are being done in your area if you are now eligible to be vaccinated. 

A few other considerations are important before going for a COVID-19 vaccine:

  • If you have a history of severe allergic reactions (i.e., you carry an “epi pen”), a compromised immune system, or a health condition that might interfere with getting the vaccine, check with your healthcare provider to figure out if you can get the COVID-19 vaccine. You may be able to get it, but need to take special precautions. For example, some people are recommended to wait for 30 minutes of observation instead of 15 minutes after getting the vaccine.
  • The CDC recommends waiting at least 14 days between receipt of a COVID-19 vaccine and any other (non-COVID-19) vaccines. 
  • Unless you regularly take a pain-relieving medication prescribed by your doctor, it is not recommended to take a pain reliever (such as ibuprofen or acetaminophen) before vaccination. These types of medications may affect how well the vaccine works. However, it is important not to stop taking a medication prescribed by your doctor before getting the vaccine without first checking that it would be safe to do so.

What to expect when getting the vaccine
If you are going to get a COVID-19 vaccine, here is an idea of what you may experience:

  • Before you go to the immunization site, remember to wear a mask and plan to social distance the same way you would in any other public space during the pandemic. Wear clothing that makes it easy to access your upper arm without removing your shirt. Take any appointment confirmation, identification, or other items requested by the site. You may also want to take a book or your phone to pass time spent waiting. In some cases, you may be asked to read information about the vaccine and complete a form on the computer before you go to the appointment. 
  • When you arrive, you will most likely be asked to sign in or confirm your appointment and eligibility. The health care professionals at the site will probably ask you and your parent or guardian a few questions before you get the vaccine. For example, they may ask if you have any history of severe allergic reaction, if you are allergic to certain things, or if you have had a vaccine in the last two weeks. 
  • After you are signed in, you may need to wait for your turn to get vaccinated. Waiting areas should be set up with social distancing measures to ensure everyone’s safety. 
  • When it is your turn, the person giving the vaccine may ask you a few more questions.  For example, they might confirm your name, ask in which arm you want the vaccine, or repeat questions about allergies or other vaccines. This repetition helps ensure that people are safely and appropriately vaccinated. It is particularly important at vaccination clinics where many people are coming and going. 
  • When the vaccine is administered, it does not take long and usually feels like a pinch. Many people find it helpful to distract themselves during the shot by looking at something across the room or talking to someone. If you feel nervous about getting the vaccine, you could also try listening to music or playing with an app to distract yourself. Other ways to decrease your nervousness and the “pinch” include taking a few slow, deep breaths as the vaccine is given, or ask for an alcohol pad to be rubbed on your opposite wrist shortly before the vaccine is administered. As the vaccine is given, blow on the area with the alcohol; you will feel the cool temperature of the alcohol evaporating more than the pinch of the shot.
  • After the shot is complete, you will most likely be asked to go to a waiting area. While the risk of an allergic reaction from a COVID-19 vaccine is very low, it makes sense for everyone to be observed after the injection as a safety precaution. People are asked to wait 15 to 30 minutes in case they have any allergic reactions to the vaccine. Although rare, these reactions can occur. They typically occur soon after getting the vaccine, which is why people are asked to wait. 
  • At some point during the appointment, you should receive a vaccination card that tells you which COVID-19 vaccine you received and the date you received it. Some people immediately take a picture of this card, so if it is misplaced, they still have the information. While it may be tempting to post a picture of your vaccination card on social media, it is not recommended to do so as the card may have personal information that should not be made public. Some vaccination sites have selfie stations or offer stickers that provide alternative ways to share your vaccination experience with your followers. 
  • You may also be asked to sign up for a second appointment if you are getting a two-dose vaccine, like the Pfizer or Moderna vaccine. The site will let you know the correct timing for your second injection. Many sites do the second appointment scheduling during the post-vaccine observation period. 

What to expect after getting the vaccine
Getting a COVID-19 vaccine is similar to other immunizations. Some people have side effects while others do not. Side effects are a sign that your body is responding to the vaccine. But don’t worry if you don’t have side effects — it doesn’t mean the vaccine didn’t work. People’s immune systems respond differently. The most common side effects are pain, redness or swelling at the injection site or tiredness, low-grade fever, or muscle aches for a day or two after getting the vaccine. For the mRNA vaccines, these side effects tend to be more common after the second dose. For more about COVID-19 vaccine side effects, check out the entry from January 14, 2021. 

To help scientists monitor vaccine side effects, you can sign up for V-Safe. V-safe is a vaccine monitoring program developed by the CDC. This program will send check-in text messages after each dose of vaccine to gather data on any symptoms you may have experienced. This system helps with continuing to monitor vaccine safety, particularly in different groups of people. Individuals across the country have participated in the program. Hopefully, you will consider participating, too, so that scientists can gather information about the vaccine experience of young people. 

Immune responses develop a couple of weeks after getting the last dose. Right now, we know that people who completed the full course of coronavirus vaccine are unlikely to get sick from COVID-19. However, we don’t yet have enough data to say how long protection lasts. We also aren’t sure whether someone who received the vaccine can still spread COVID-19 to unvaccinated people. For those reasons, people should still wear masks and social distance when in public, even after getting the COVID-19 vaccine. As scientists continue to learn more about the force of this pandemic, these recommendations may change. For example, recently, the CDC indicated that fully vaccinated people can get together in small groups in homes or non-public places without wearing masks.

As more and more people get vaccinated, more and more restrictions will be lifted. For this reason, it is important that everyone who can get vaccinated do so — not only for themselves, but also for those around them and for the community at large.

Think about it: 

  1. Why do you think it is important to do vaccine clinical trials on teens and children rather than relying on the findings in adults?
  2. How do you think the experience of a teen receiving a vaccine would be different from that of a parent or other adult?

Related resources
Your COVID-19 Vaccine Appointment, CDC 
Age Groups and Vaccines: Teens/College, VEC 
Questions and Answers about COVID-19 vaccines, VEC

Download this article [PDF, 164 KB]

March 10  

Will the COVID-19 vaccines work on the newer variants of coronavirus?    

Scientists hope the answer to the above question will be yes. So far, the limited data we have suggests that the current mRNA vaccines and the newer adenovirus-vector vaccine will be effective against most existing variants. Let’s review how viruses evolve and how vaccines work to understand why these variants are causing concern. 

How viruses evolve
Viruses that reproduce in people infiltrate human cells so they can use the cells’ machinery to replicate. Every time a virus reproduces in a cell, its genetic material is copied. During the copying process there is an opportunity for the virus to change or evolve. This can happen in one of two ways: 

  1. Mutation: A virus can change if a mistake occurs when the viral DNA or RNA is copied. For example, information can be left out or entered in the wrong place. RNA viruses tend to be “sloppy” and make mistakes during the copying process that result in mutations.  
  2. Recombination: A virus can change by sharing genetic material with another virus that has infected the cell at the same time. 

When a virus changes, the new version of the virus is called a variant. When the variant replicates, that mutation is also replicated. Sometimes, these new variant viruses have an advantage over previous versions. For example, the mutation might help the virus spread from one person to another more easily. When this happens, the variant with the advantageous mutation will be more likely to survive than older versions. In the case of SARS-CoV-2, the virus that causes COVID-19, recent variants have been in the news. Scientists are working to understand if these new versions of the virus are stopped by antibodies produced through vaccination. 

Watch this short animation about how coronaviruses evolve.

How a vaccine could stop working against a new variant 
First, let’s review how the current COVID-19 vaccines work. These vaccines train the body to recognize and neutralize the spike protein on the surface of the SARS-CoV-2 virus. As part of this immune system training, the body develops antibodies to the spike protein. These antibodies float around in the blood checking to find a protein that they can bind to. Wherever a protein match is found, the antibodies bind to them and prevent the virus from attaching to cells. 

Antibodies generated after vaccination might not be able to bind to the spike protein if the virus evolves in a way that changes the shape of the spike. In this manner, the variant virus will no longer be prevented from attaching to the person’s cells.  So, how can scientists tell if a new variant can evade existing antibodies?

Scientists can evaluate the ability of the vaccines to stop new variants in a few ways:

  1. Antibody studies – Scientists can combine antibodies from vaccinated people with new versions of the virus in the lab. They test to see if the antibodies can “neutralize” the virus or stop it from infecting cells. If the antibodies work in the lab, it is likely that they would also stop the virus from infecting vaccinated people in the community. It is important to recognize that while these studies are the fastest to do, they do not tell us everything we need to know. Antibodies are only one part of the body’s immune system defenses. Even if they do not completely neutralize the virus, other immune system components may still be able to protect a vaccinated person from getting sick. 
  2. “Real world” studies – Over time, scientists can monitor people who have been vaccinated or naturally infected. They check to see if they are becoming sick with the different variants despite the immunity that was generated by natural infection or vaccination. These studies are more challenging and expensive to do.

What happens if the vaccines don’t work against the variants?
If scientists find that vaccinated people are not protected against newer variants, they can revise existing vaccines to better match the variants. This is what is done each year for influenza. The influenza virus changes so rapidly that scientists need to make a new version each year. Hopefully, one day scientists will be able to create a so-called “universal” influenza vaccine — one that will protect against influenza no matter how much the virus changes. 

As with influenza, scientists are monitoring SARS-CoV-2 and the new COVID-19 vaccines. They are working to create revised vaccines in case the current ones become less effective. If this happens, people might need to get a booster dose. Or, if the virus continues to spread rapidly and change, people may need to get multiple booster or annual doses. Right now, scientists do not think people will need annual COVID-19 vaccines, but time will tell.

When viruses replicate, they often change. If those changes are advantageous, new versions, called variants, will become more common. As variants arise, they may also be able to evade immunity caused by previous infection or vaccination. In the case of SARS-CoV-2, current research suggests that the COVID-19 vaccines will continue to offer protection, but scientists will continue to monitor variants in case something changes.

Think about it:

  1. Based on the discussion above, how does the number of people who become infected affect the chance of a new variant forming? How do the number of variants affect the chance of needing to revise vaccines?
  2. If you were a public health professional, what would be your recommendation(s) for how society could avoid or decrease the opportunity for variants to develop? 
  3. If you were a scientist working on vaccine development, how would you prepare for the chance that variants might arise?
  4. If a variant formed that our current vaccines didn’t work against at all, what steps do you think would need to be taken to protect people from it?

Related resources
Biology of SARS-CoV-2: Evolution (Animation), HHMI BioInteractive 
Emerging SARS-CoV-2 Variants, CDC 
Unit 2 Lesson 2: Case Studies: Influenza and HIV, VMP  
This lesson focuses on the mechanisms by which viruses infect cells and replicate. The lesson also covers genetic processes by which viruses are able to circumvent immune system defenses.

February 16 

What is the difference in the immune response between vaccinated and unvaccinated people? 

Please take a few minutes to review this image and see what you can conclude from it before reading the rest of the passage.

vaccinated vs. unvaccinated graphic
Download this image [PDF, 130 KB]

Hopefully, you were able to tell that vaccination causes changes in our immune system’s response to a virus. But because often nothing noticeable happens when vaccinated people are exposed to a virus, sometimes it is difficult to know that vaccination made a difference. So, let’s consider the different immune system reactions of two people exposed to SARS-CoV-2, the virus that causes COVID-19:

  • Mr. Smith has not yet received his COVID-19 vaccine.
  • Ms. Jones received both recommended doses of the COVID-19 vaccine. She finished her last dose one month ago.

Mr. Smith and Ms. Jones are teachers at the same school. After a recent staff meeting, they find out that they were both exposed to COVID-19 when another teacher did not realize he was infected. 

Watch this short animation as a reminder of how a virus infects cells. 

Mr. Smith’s immune system response
(represented by the “No vaccination” part of the diagram)

When the virus attaches to Mr. Smith’s cells and starts reproducing, new virus particles are released from infected cells. These cells infect nearby cells to start the process over again. In the diagram above, these repetitive cycles of viral replication are demonstrated by the pink arrows. The increasing pink color shows that as these cycles repeat, more viral particles are available to continue the process. This increasing amount of virus makes it more difficult for Mr. Smith’s immune system to stop the infection.

In the early days of the infection, Mr. Smith’s innate immune response will be in charge because his body has not encountered the SARS-CoV-2 virus previously. This is shown in the blue circle in the diagram. It will take about 5 to 7 days before the innate immune response starts to get significant help from the adaptive immune system. 

The important difference between the innate and adaptive immune response is the method by which they respond to an infection. Innate immunity is non-specific; it is meant to be a first line of defense. On the other hand, adaptive immunity is specific, meaning its components have special training. In this case, adaptive immune system responses are targeted against the SARS-CoV-2 virus. As demonstrated by the green circle in the diagram, once the adaptive immune response starts, the immune system can more quickly control the infection. 

After about a week to ten days, Mr. Smith’s immune system gains control, and he feels better. Unfortunately, Mr. Smith’s wife is now feeling “under the weather,” even though Mr. Smith thought he did a good job of staying isolated while he was sick.

Ms. Jones’ immune system response
(represented by the “Vaccination” part of the diagram)

It is possible that Ms. Jones’ immune system will recognize the SARS-CoV-2 virus before it can get into any of her cells and begin replicating. If this happens, she will not have any symptoms and she will not be capable of spreading the virus to anyone else. But it is also possible that a few viral particles could still replicate before Ms. Jones’ immune system realizes that she has been exposed. As in Mr. Smith’s case, the pink arrows indicate viral replication. You can see that virus does not have as much opportunity to replicate in Ms. Jones’ cells.

This is because Ms. Jones has been vaccinated. The vaccination allowed her immune system to train specialized forces to recognize the SARS-CoV-2 virus. As a result, her adaptive immune response (represented by the green circle) is able to jump into action much more quickly (within 1 to 3 days) than Mr. Smith’s did. The result is that the innate immune response (represented by the blue circle) is in charge for much less time, and Ms. Jones’ infection is shut down much more quickly. If Ms. Jones feels sick at all, she will have fewer symptoms for fewer days.

Think about it: 

  1. What differences did vaccination make for Ms. Jones' experience? 
  2. If Mr. Smith is exposed to the SARS-CoV-2 virus in the future, what do you think his diagram would look like? Why?
  3. Watch the animation, "The Innate and Adaptive Immune Systems," and think about how the information in the animation relates to the diagram and the experiences of Mr. Smith and Ms. Jones, Be prepared to share your observations in a class discussion. 

February 1 

Why are they having trouble getting the vaccine to people who want it?

Getting COVID-19 vaccines to the public has been challenging in the early days after their approval, so let’s consider a few reasons why.

The vaccines
All vaccines must be transported and stored in a way that maintains their effectiveness.

Both COVID-19 mRNA vaccines are temperature sensitive: 

  • The Pfizer vaccine must be stored at -70 degrees Celsius (°C), which is much colder than the freezers that we use in our houses. In fact, this is even colder than the average temperature of central Antarctica. 
  • The Moderna vaccine can be stored at “warmer” temperatures of about -20°C. 

In addition to the temperature requirements, once these vaccines are thawed, they cannot be frozen again. And, once doses are taken out of the vial, the remaining doses must be used within a few hours.

These requirements mean that a lot of planning needs to go into vaccine transport, storage and use.  

The supply
The number of people who want to get the COVID-19 vaccine is extremely high. And, in order to stop transmission of this virus in our communities, millions and millions of people will need to be vaccinated. 

On the other hand, COVID-19 vaccines are new. Because of the pandemic, production of the vaccines was allowed to start during the clinical trials to save time. If the vaccines did not work or were not safe, they would have been thrown away. Luckily, that did not happen with the mRNA vaccines. But, even with the faster production schedule, it will still take time to make enough doses of these vaccines to immunize the majority of people in this country and around the world.

In sum, the number of people who want the vaccine combined with the fact that these are new vaccines creates a big gap between supply and demand. 

The situation
Everything is more difficult in a pandemic. We cannot do things in the way we would typically do them. For example, normally when people want something, they wait in line for it. But, because of social distancing to try to slow the spread of the virus, this is not an option. And, some of the things that might be done in the summer, like moving people outside and spreading them out, are not possible when the weather is cold and unpredictable. Even though there are some ways to work around these issues, the fact remains that the risk of spreading COVID-19 itself makes organizing vaccine clinics more challenging.

The distribution plan
One of the biggest challenges has been that there has not been one centralized plan for administering vaccines. Plans for distributing the vaccine vary from state to state and sometimes even from county to county. While this makes sense in some ways because different places have different situations, a single general approach that varies in minor ways would be less confusing to the public and easier for those in charge of distribution.  

Another aspect of the distribution plan is its sheer size. Millions and millions of people are waiting to get a COVID-19 vaccine. People working on distribution are trying to make sure not only that a lot of people get vaccinated, but also that the vaccine distribution is equitable for people with different backgrounds and situations all over the country. In an attempt to address this, the Centers for Disease Control and Prevention (CDC) made recommendations regarding vaccine prioritization. 

While the CDC recommendations offer guidelines, it is up to each state to decide how to allocate the vaccines they receive. So, people living in one state might have different eligibility and prioritization schedules than family and friends living in another state.

Just because something is challenging doesn’t mean that it can’t be done. But it does mean that it will take hard work, creativity, and some patience.

Think about it:

  1. If you were in charge of COVID-19 vaccine delivery for your town/city, how would you do it? 
        a. How would you decide who gets the limited doses?
        b. How would you have people schedule their appointments? 
        c. Where would you hold vaccine clinics? 
        d. How would you set up the clinics to keep everyone safe and ensure that you
            have enough people, so that you don’t waste any doses of vaccine?
  2. What are some of the advantages of having local areas organize their own vaccine administration? What are some disadvantages?
  3. If someone gave you the chance to help decide who would get immunized first, would you want to be part of that team? 
  4. Choose 2 state health department websites and review the COVID-19 vaccine distribution information. How are their approaches similar? How are they different?

Related resources:
When Vaccine is Limited, Who Should Get Vaccinated First?, CDC 
Pfizer-BioNTech COVID-19 Vaccine Storage and Handling Summary, CDC
Moderna COVID-19 Vaccine Storage and Handling Summary, CDC 


January 14 

What are the side effects of the COVID-19 mRNA vaccines? 

  • Side effect: An effect that occurs after receipt of a medication or vaccine. Even though these are unwanted, they can be expected based on previous experience (e.g., clinical trials) and result despite proper use of the medication or vaccine.
  • Adverse effect: An unexpected effect that occurs after receipt of a medication or vaccine, which may or may not be caused by the medication or vaccine.

Watch this short video to learn more about the differences between side effects and adverse effects.

Side effects after COVID-19 mRNA vaccines 
People are sometimes surprised when they have a side effect following a vaccine or medication, and they may perceive these effects as problematic. But, side effects do not mean there is a problem. For example, the two new mRNA COVID-19 vaccines have resulted in side effects, such as: 

  • sore arm (at injection site)
  • tiredness 
  • headache
  • muscle or joint aches
  • fever or chills

These side effects typically occur in the first few days after receiving the vaccine, and in the case of both new mRNA COVID-19 vaccines, the side effects were more likely after the second dose. Further, younger people were more likely to experience side effects than older people. So, why does this happen and what does it mean related to the COVID-19 mRNA vaccines?

  1. In some cases, side effects indicate that your immune system is working to defend against the vaccine. Side effects are often part of the immune response generated by our bodies. For example, aches and pains result from changes that we can’t see, like swelling, as immune system cells move into the area where a “foreign invader” has been identified. Redness can result from increased blood flow to the area of the immune response, and fever is the body “turning up the temperature” to increase the effectiveness of the immune system and decrease the effectiveness of a perceived pathogen. As you might have realized, many side effects are things we describe as symptoms when we are sick, but in that case, too, it is our immune system responding to a “foreign invader.”
  2. Side effects occur in the first day or two after the vaccine because the immune system is working. After a vaccine is administered, it takes several hours for the immune response to “ramp up” and respond to what it perceives as a “foreign invader.” Often, the first effects will be closest to the injection site, like pain and redness at the site of the injection, with later effects being further from the injection site or widespread, like fever.
  3. The greater number of side effects after the second dose and among younger recipients suggest that mRNA vaccines invoke strong immune responses. So, even though side effects might make you “feel sick,” you aren’t actually infected. Your immune system is just responding to the vaccine. Like a fire drill, the COVID-19 vaccine trains your body to protect you from SARS-CoV-2 if you are exposed to it in the future. 

Adverse events after COVID-19 mRNA vaccines
So far, one adverse event following COVID-19 mRNA vaccines has been identified. Specifically, a small number of people have had severe allergic reactions, called anaphylaxis. Currently, it is estimated that this severe allergic reaction has occurred in about 11 of every 1 million people who got the vaccine. Because these types of allergic reactions tend to occur very quickly after someone gets the vaccine, people are being advised to stay at the site where the injection was given for 15 to 30 minutes after getting vaccinated. No one has died from this reaction. Likewise, scientists and public health experts have systems in place to learn more about these reactions as well as monitor for other adverse events on an ongoing basis.

Think about it: 

  1. Do you think some people might confuse side effects with actual illness? Why or why not? 
  2. Why do you think some people experience side effects, but others do not? 
  3. If a person experienced a physical condition in the days after receiving a vaccine, like indigestion or a racing heart, do you think they might believe the vaccine was the cause even if the evidence proved otherwise? Why or why not? 

Related resources
Unit 1, Lesson 2 – The Innate Immune Response 
What to Expect after Getting a COVID-19 Vaccine, CDC
Side Effects and COVID-19 Vaccines: What to Expect, John Hopkins Bloomberg School of Public Health

To see the archive of questions from 2020, please visit the Archived Coronavirus Pandemic Questions page