Vaccines: Frequently Asked Questions

Ensuring all Coloradans receive a vaccination in a timely and effective manner is a core part of COVIDCheck Colorado’s mission to bring the most equitable and innovative response to COVID-19 to our partners.

COVIDCheck Colorado is currently working with several vaccine providers to accelerate vaccination rollout across the state and deliver doses to your community with the same speed and reliability we have offered in our testing program.  Vaccine distribution is NOT currently available at our testing sites. Please continue to monitor our website and social media to get regular updates on where and when vaccines will be made available.

In the meantime, if you are interested in learning more about the vaccine and what to know when you are eligible to receive it, please read the following FAQs.

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When can I get the vaccine?

We’re following Colorado’s phased eligibility guidelines, listed here. Please add your name and information to our registry. When you are eligible and there is an appointment for you in our community, we’ll reach out to let you know.

If I’m on the registry, does that mean I have an appointment?

No. The registry lets us know who is interested and eligible. When there are appointments available, we randomly select people from the registry to contact with the appointment opportunity. This process is completely randomized to ensure the most equitable distribution of vaccines.


I’m already on a registry. Can I sign up for more than one?

Absolutely. You can sign up on as many registries as you’d like.


Is the registry for all vaccine sites affiliated with COVIDCheck Colorado?

We’re using this registry for most of the locations affiliated with COVIDCheck Colorado.


What happens with my information?

Your information is secure. COVIDCheck Colorado is a HIPAA-compliant entity, as is our partner PrimaryBio.


How does each of the available Covid-19 vaccines work?

Two vaccines are currently available in the United States, one developed by Pfizer/BioNTech (BNT162b2) and the other by Moderna (mRNA-1273). Both vaccines work via a novel messenger RNA (mRNA) mechanism. In these vaccines, the mRNA carries instructions to make the SARS-CoV-2 “spike” protein — the prickly projections on the surface of the virus. Once the vaccine is injected, the mRNA is taken up by the macrophages near the injection site and instructs those cells to make the spike protein. The spike protein then appears on the surface of the macrophages, inducing an immune response that mimics the way we fight off infections and protects us from natural infection with SARS-CoV-2. Enzymes in the body then degrade and dispose of the mRNA. No live virus is involved, and no genetic material enters the nucleus of the cells.

The Johnson and Johnson (JNJ-78436735) vaccine works via a viral vector mechanism. In this vaccine, the vector (not the virus that causes COVID-19, but a different, harmless virus) will enter a cell in your body and then instruct that cell to produce just the spike protein of the SARS-CoV-2 virus. The spike protein then appears on the surface of the cell, inducing an immune response that mimics the way we fight off infections and protects us from natural infection with SARS-CoV-2

How many shots do I need for the vaccine to work?

Both the Moderna and Pfizer immunizations require two shots; the Pfizer vaccine requires two shots 21 days apart and Moderna immunization requires two shots 28 days apart. The Johnson and Johnson vaccine only requires one shot.

How long does it take for the vaccine to work?

It may take up to one or two weeks after your last dose of the vaccine to have protection.

What’s it like to get a COVID-19 Vaccination?

Many say the COVID vaccine is very similar to a flu shot.  Your arm will likely hurt afterwards, which is a sign that the antibodies are being activated. Some people experience muscle aches, chills and a fever. Many more have zero symptoms beyond a sore arm.

The vaccine was developed very quickly. Does that mean it's unsafe?

The COVID vaccine went through a rapid development and approval process for which we should all be grateful, given the toll that the disease has taken on our community. One of the reasons scientists were able to create this vaccine faster than others in the past is modern scientific tools are faster than old ones. In addition creating these vaccines was a collaborative, global effort – governments, academics, and private companies across the world worked together to reduce and remove the usual barriers or delays in vaccine research, production, and distribution. In both clinical trials (where tens of thousands of people are enrolled to get vaccines and placebos, and are followed over time) the Moderna and Pfizer vaccines were determined to be safe and 94%-95% effective after two doses. If there were any doubts about safety, the drugs would not have been approved.

What about side effects?

After receiving the vaccine, a very small number of people have had allergic reactions, such as shortness of breath, lightheadedness, and rashes after vaccination. In a small number of cases these reactions have required medical attention. — All vaccination clinics are equipped to deal with these rare situations on site. Just as with other vaccines, the COVID-19 vaccines can cause temporary effects soon after they enter the body and start teaching the immune system to go after the coronavirus — this actually means the vaccine is working! Tens of thousands of people have received the vaccines in clinical trials, and hundreds of thousands more Americans are getting it every day without any side effects.

What about long-term effects?

You may have heard claims that the COVID-19 vaccine will have long-term negative effects on the body. None of these are true! When we see side-effects from vaccines, we will generally see anything significant within the first two months. Health officials are watching out for any patterns of problems that are out of the ordinary. So far, they have not seen any. With the scrutiny on these vaccines, combined with the fact that there are many more varieties of the COVID-19 vaccine now being tested, it means that we would have an early warning and alternatives.

Will the vaccines work against the emerging strains of SARS-CoV-2?

While evidence has shown that the Johnson and Johnson vaccine is slightly less effective against preventing asymptomatic infection of certain SARS-CoV-2 variants (most notably in South Africa), it is important to note that this vaccine has been shown to be extremely effective at preventing severe infection and death against all worldwide variants. Currently there is limited information on how effective the mRNA vaccines (Moderna and Pfizer) will be against emerging strains of SARS-CoV-2, as their clinical trials preceded the identification of the major variants present now in multiple countries around the world. Preliminary studies (not yet peer reviewed and published) suggest that these vaccines are also more protective against some of the variants than others, similar to what was found in clinical trials for the Johnson and Johnson vaccine. 

From a practical perspective, the discovery of these variants does not change the basic recommendations for vaccination. Specifically, right now it is recommended that every individual receive the first vaccine available to them in order to stop the spread of any form of COVID-19.

I’ve read that more people will die as a result of a negative side effect to the COVID-19 vaccine than would actually die from the virus. Is this true?

This is not true. There are claims that COVID-19’s mortality rate is 1%-2% and that people should not be vaccinated against a virus with a high survival rate. However, a 1% mortality rate is 10 times more lethal than the seasonal flu. And, the mortality rate can vary widely and is influenced by age, sex, zip code, and underlying health condition. It’s important to recognize that getting the vaccine is not just about surviving COVID-19. It’s about preventing spread of the virus to others and preventing infection that can lead to long-term negative health effects.

Should I get a COVID-19 vaccine if I have a history of allergic reactions?

You should discuss with your doctor if it makes sense for you based on your medical history. In general:

    • If you have a history of severe allergic reactions not related to vaccines or injectable medications, you may still get a COVID-19 vaccine, but you should be monitored for 30 minutes after getting the vaccine. 

    • If you’ve ever had an immediate allergic reaction to any ingredient in a COVID-19 vaccine, the Centers for Disease Control and Prevention recommends not getting that specific vaccine. 

    • If you are allergic to polysorbate, you should not get an mRNA COVID-19 vaccine. 

    • If you have an immediate allergic reaction after getting the first dose of a COVID-19 vaccine, you should not get the second dose.

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

However, before getting the vaccine, your symptoms should be resolved (if you had any) AND you should have completed your recommended isolation.

Will I be required to get a vaccine for work?

The federal government does not mandate (require) vaccination for individuals. For some healthcare workers or essential employees, a state or local government or employer, for example, may require or mandate that workers be vaccinated as a matter of state or other law. Check with your employer to see if they have any rules that apply to you.

Can I get a COVID-19 the same time as another vaccine?

  • Wait at least 14 days before getting any other vaccine, including a flu or shingles vaccine, if you get your COVID-19 vaccine first. And if you get another vaccine first, wait at least 14 days before getting your COVID-19 vaccine.
  • If a COVID-19 vaccine is inadvertently given within 14 days of another vaccine, you do not need to restart the COVID-19 vaccine series; you should still complete the series on schedule. When more data are available on the safety and effectiveness of COVID-19 vaccines administered simultaneously with other vaccines, CDC may update this recommendation.

Is it safe for me to get a COVID-19 vaccine if I’m pregnant or breastfeeding?

  • People who are pregnant and part of a group recommended to receive the COVID-19 vaccine may choose to be vaccinated. If you have questions about getting vaccinated, talking with a healthcare provider might help you make an informed decision. While breastfeeding is an important consideration, it is rarely a safety concern with vaccines.
  • No data are available yet on the safety of COVID-19 vaccines in lactating women or on the effects of mRNA vaccines on breastfed infants or on milk production/excretion. mRNA vaccines are not thought to be a risk to breastfeeding infants. People who are breastfeeding and are part of a group recommended to receive a COVID-19 vaccine, such as healthcare personnel, may choose to be vaccinated.
  • To make sure that more information is gathered regarding the safety of these vaccines when administered during pregnancy, pregnant people are encouraged to enroll in v-safe, CDC’s new smartphone-based tool being used to check-in on people’s health after they receive a COVID-19 vaccine. If pregnant people report health events through v-safe after vaccination, someone from CDC may call to check on them and get more information. Additionally, pregnant people enrolled in v-safe will be contacted by CDC and asked to participate in a pregnancy registry that will monitor them through pregnancy and the first 3 months of infancy. Learn more about COVID-19 vaccination considerations for people who are pregnant or breastfeeding.

Is it safe for me to get a vaccine if I have an underlying medical condition?

  • People with underlying medical conditions can receive the FDA-authorized COVID-19 vaccines provided they have not had an immediate or severe allergic reaction to a COVID-19 vaccine or to any of the ingredients in the vaccine. Learn more about vaccination considerations for persons with underlying medical conditions. Vaccination is an important consideration for adults of any age with certain underlying medical conditions because they are at increased risk for severe illness from the virus that causes COVID-19.

Is one vaccine preferable to the other for specific patients?

The Pfizer/BioNTech vaccine is authorized for ages ≥16 years, and Moderna’s for ≥18 years. Aside from this age difference, there is no target population better suited to one vaccine or the other.

What is V-Safe? Should I enroll?

After receiving the Covid-19 vaccine, patients have the option of enrolling in v-safe. This CDC smartphone-based tool provides automated check-ins after Covid-19 vaccination, allowing people to report side effects using a secure online site. For those reporting severe or notable side effects, a CDC official may call to collect more details about what happened. In addition to collecting this information, v-safe will also send reminders about receiving the second vaccine. Although enrolling in v-safe is voluntary, we encourage you to participate.

What is causing delays in vaccine rollout?

There are many variables in play in getting vaccines to recipients, including supply distribution from the pharmaceutical companies to the federal then state then local government.  The new administration has communicated a commitment to getting more vaccine doses out more quickly. We are monitoring all of these variables closely to make sure we are well positioned to work with you as soon as possible.

I’ve heard that some teachers are already getting vaccines. Am I being left out?

Some health systems have a lottery in place allowing individuals beyond group 1A to get vaccinated now.   This is an exception more than a rule that stems from the local public county health system’s understanding of vaccine supply and demand in a given region.

How is Personal Health Information (PHI) protected?

COVIDCheck Colorado is a HIPAA-compliant entity, as is our partner PrimaryBio.

Do you need health insurance to receive the COVID-19 vaccines?

No, anyone can get a vaccine with or without insurance.

Will I need to pay for the vaccine?

No. Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost. Our lab may bill an individual’s insurance for a vaccine administration fee, but if insurance rejects the claim, neither we (CCC) nor our partner labs will ever ask that the individual, or your organization, pay for the cost of the test.

Do I need a government-issued ID to be vaccinated?

No. The state of Colorado has told health providers not to check government IDs at vaccination sites.

State and local public health agencies will never share your information for any immigration or law enforcement purposes; information will only be used for public health purposes. Receiving the COVID-19 vaccine will not count against you in any public charge determinations.

Do I still need to wear a mask/practice social distancing after I receive 2 doses of the vaccine?

Yes. While experts learn more about the protection that COVID-19 vaccines provide under real-life conditions, it will be important for everyone to continue using all the tools available to help stop this pandemic.