Learn about COVID-19 vaccines

Last updated August 4, 2021.

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All Coloradans over age 5 are now eligible to be vaccinated. Find a vaccine clinic near you.

 

COVID-19 vaccines

Any of the authorized vaccines will help to keep you safe. 

Authorized and recommended COVID-19 vaccines:

Pfizer

Moderna

Janssen

mRNA vaccine:

Pfizer’s vaccine uses single-stranded mRNA to teach your body how to fight COVID-19. This genetic code isn’t a live virus, and it can’t change your genes.

mRNA vaccine:

Moderna’s vaccine uses single-stranded mRNA to teach your body how to fight COVID-19. This genetic code isn’t a live virus, and it can’t change your genes.

Viral vector vaccine:

Janssen’s vaccine uses double-stranded DNA inside a modified, harmless adenovirus to teach your body how to fight COVID-19. This vaccine doesn’t contain a live virus, and it can’t change your genes.

Two doses:

Pfizer’s vaccine requires two doses, given 21 days apart.

Two doses:

Moderna’s vaccine requires two doses, given 28 days apart.

One dose:

Janssen’s vaccine requires only one dose.

Side effects:

The most common side effects of all three vaccines are tiredness, headaches, body aches, and redness or pain at the injection site. Side effects may be more pronounced after the second dose of a two-dose vaccine.

Monitoring for allergic reactions: 

After receiving any of the three available vaccines, you’ll be monitored for rare severe allergic reactions. You should be monitored for 15 minutes after vaccination, or 30 minutes if you have a history of anaphylaxis.

Testing:

Phase 3 trials included 46,331 participants from six countries. 42% identified as Asian, Black/African American, Hispanic/Latino/a, or Native American.

Testing:

Phase 3 trials included 30,000 participants from the U.S. About 37% of volunteers identified as Asian, Black/African American, Hispanic/Latino/a, or other.


 

Testing:

Phase 3 trials included 43,783 participants from the U.S., Latin America, and South Africa. 77.7% identified as Asian, Black/African American, Hispanic/Latino/a, or Native American. This trial ran while variant strains were circulating around the world. 

Storage:

Pfizer’s vaccine needs to be stored in ultra-cold freezers in order to stay effective.

Storage:

Moderna’s vaccine needs to be frozen, but not in ultra-cold freezers.

Storage:

Janssen’s vaccine can be stored for up to three months at normal refrigerator temperatures.

Safety:

After looking at data from clinical trials, the FDA found all three vaccines to be safe and effective at preventing severe COVID-19 disease.

Vaccines in phase 3 clinical trials: Astrazeneca, Novavax

 

Safety and effectiveness of the vaccines

Vaccines must be proven to be safe and effective before they are given to people. The COVID-19 vaccines are no different. These vaccines are being proven safe every day, as hundreds of thousands of Coloradans -– doctors, nurses, seniors, and others -– have already taken them. Nationally, many millions of people have also received the vaccine.

 

Testing vaccines for safety and effectiveness

Once a company develops a vaccine, it must go through a rigorous scientific testing process before it can submit the vaccine to the Food and Drug Administration (FDA). Each phase of this process includes clinical research studies or trials.

People volunteer to take part in these trials. Each trial emphasizes the safety of the vaccine on people. The trials also show researchers how well the vaccine works. As the research moves to the next phase, the group of volunteers becomes bigger to include more diversity in people and circumstances. A diverse group of people volunteered to participate in every phase of the clinical trials, including populations disproportionately impacted by COVID-19 due to generations of systemic inequities. 

The FDA independently reviews the information from these tests to make sure the vaccine is safe and works well. It then decides whether the vaccine can be made available to the public. All vaccines must undergo this rigorous scientific process. The FDA held the COVID-19 vaccines to the same safety standards as other vaccines.

 

Why should I consider getting vaccinated?

So we can go back to the Colorado we love.

Fully vaccinated people can go back to doing many of the things we were able to do before the pandemic. This past year has been tough, and we’ve suffered through a lot. The vaccines will help us get back to work, back to spending time with family, and back to a more normal life.

To help protect people from getting COVID-19.

Getting the COVID-19 vaccine is an effective way to stop people from getting really sick or dying from COVID-19. Being vaccinated means that you are protected from getting seriously ill. It may also reduce the chance that you could spread COVID-19 to others who are more vulnerable.

The vaccines are free whether or not you have health insurance or are a U.S. citizen.

The vaccines are free. Medicare, Medicaid, and private insurance will cover the cost of the COVID-19 vaccines. In addition, uninsured Coloradans will have access to free vaccines. Providers cannot turn away anyone because they can’t pay for the vaccine or don’t have health insurance. Providers also cannot require ID before offering you a vaccine.

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

 

What can I expect at my vaccine appointment?

At your appointment, you should receive an FDA fact sheet that tells you more about the risks and benefits of the specific COVID-19 vaccine you will receive. You should also receive a vaccination card or printout that tells you which COVID-19 vaccine you received, the date you received it, and the location you received it. Keep this card as a reminder of when you need to get your second dose, if applicable. The second dose of any COVID-19 vaccine must be the same vaccine product as your first dose. It is very important to get both doses of the vaccine so that your body develops enough antibodies to fight the COVID-19 virus if you get infected at a later time.
You may experience side effects, especially after receiving the second dose of the vaccine. These symptoms are normal and show that your body’s immune system is responding to a vaccine. These side effects typically go away on their own after a few days.

For more information, see the following links:

 

Reporting adverse events

If you are experiencing a medical emergency, seek immediate assistance from a healthcare provider or call 9-1-1. 
The CDC and FDA are closely monitoring COVID-19 vaccine(s) for new risks and serious side effects. We highly encourage the public to report possible side effects (called adverse events) to the Vaccine Adverse Event Reporting System (VAERS). This national system collects the data to look for adverse events that are unexpected, appear to happen more often than expected, or have unusual patterns of occurrence. Anyone can submit a report, including parents, patients, and health care professionals. Reporting to VAERS helps the CDC monitor the safety of vaccines. 

 

Sign up for v-safe

CDC’s v-safe is a new smartphone-based, after-vaccination health checker for people who receive COVID-19 vaccines. When you receive your vaccine, you should also receive a v-safe information sheet telling you how to enroll in v-safe. If you enroll, you will receive regular text messages directing you to surveys where you can report any problems or adverse reactions you have after receiving a COVID-19 vaccine. V-safe is available in English, Korean, simplified Chinese, Spanish, and Vietnamese.

 

Where can I get vaccinated? 

Frequently asked questions

  • All available vaccines are shown to be highly effective at preventing moderate, severe, and critical COVID-19 illness, hospitalization and death. 
  • Getting any authorized COVID-19 vaccine will give you more protection than not getting a COVID-19 vaccine. All authorized COVID-19 vaccines are effective tools in stopping the crisis brought on by the pandemic as quickly as possible. 

  • No. None of the currently authorized vaccines contain the SARS-CoV-2 virus, the virus that causes COVID-19 disease. All authorized vaccines are inactivated. The Janssen (Johnson & Johnson) vaccine contains a modified adenovirus, a different, harmless virus, but this virus cannot replicate itself or make you sick.

  • Researchers had to work quickly, but not at the risk of anyone’s safety. They did not skip any steps. Safety and effectiveness were the top priorities. 
  • The timeline for developing COVID-19 vaccines was possible for several reasons: 
    • Researchers relied on years of previous research on other viruses and vaccines to help develop COVID-19 vaccines. 
    • Everyone involved dedicated all their resources and time to developing a COVID-19 vaccine. This includes research institutions, pharmaceutical companies, government agencies, and philanthropic organizations. 
    • Many governments around the world, including the U.S. government, and private funders invested in the vaccine, which allowed pharmaceutical companies to focus on research right away. 
    • Because of the financial support, researchers were able to conduct different parts of the development process on parallel tracks instead of one after another. 

  • Vaccines must be proven to be safe and effective before they are given to people. The COVID-19 vaccines are no different. These vaccines are being proven safe every day, as hundreds of thousands of Coloradans – doctors, nurses, seniors, and others – have already taken them.  Nationally, many millions of people have also received the vaccine.
  • The FDA requires that vaccines undergo a rigorous scientific process before they authorize or approve a vaccine. This process includes three phases of clinical trials. The COVID-19 vaccines are subject to the same safety standards as other vaccines. 

  • People volunteer to take part in clinical research studies. All study volunteers must go through a process called informed consent that ensures they understand all of the risks and benefits of being in a study. Those volunteers are reminded that they may leave a study at any time without losing any of their rights or benefits. 
  • Each clinical trial emphasizes the safety of the vaccine on people. As the research moves through to the next phase, the group of volunteers becomes bigger to include more diversity in people and circumstances. 
  • A diverse group of people volunteered to participate in every phase of the clinical trials, including populations disproportionately impacted by COVID-19 due to generations of systemic inequities. For example, in Pfizer’s clinical trials, about 42% of volunteers identified as Asian, Black/African American, Hispanic/Latino/a, or Native American. About 37% of volunteers for Moderna’s trials identified as Asian, Black/African American, Hispanic/Latino/a, or other.

  • Today’s vaccines use only the ingredients they need to be as safe and effective as possible. Each ingredient in a vaccine serves a specific purpose: provide immunity (protection) and keep the vaccine safe and long-lasting.
  • For a full list of ingredients, please see each vaccine’s fact sheet (Moderna, Pfizer, or Janssen). 

  • Janssen’s (Johnson & Johnson) vaccine includes ethanol, a form of alcohol, as an inactive ingredient.
  • None of the currently authorized vaccines contain human cells or tissue. However, some human cell lines were used in the production of Janssen’s vaccine. Pfizer and Moderna used human cell lines to test their vaccines.
    • Human cell lines are sometimes used in the early stages of vaccine development because viruses from which those vaccines are made need living cells to reproduce. These cell lines originally came from fetal tissue more than 30 years ago. None of the original tissue remains today: all descended cells are grown in labs. No new fetal tissue is required in the ongoing development and production of vaccines.
    • As with all viral vector vaccines, multiple purification steps ensure that cells are not in the final vaccine product.
    • For more information about human cell lines, please see the College of Physicians of Philadelphia’s webpage Human Cell Strains in Vaccine Development.
    • For a full list of ingredients, please see each vaccine’s fact sheet (Moderna, or Pfizer, or Janssen). 
    • If you have ethical concerns about the vaccines, we encourage you to talk to your faith leaders about them.

  • Currently, there is no scientific reason or evidence to suggest COVID-19 vaccines have any effect on fertility. Clinicians and researchers will continue to closely monitor for any issues. Please talk with your doctor about any concerns.

  • Pregnant or breastfeeding people may choose to be vaccinated when the vaccine becomes available to them. Talking to a health care provider may help with deciding whether to get the vaccine, but it is not required for vaccination.
  • Based on current knowledge, experts believe that the currently authorized COVID-19 vaccines are unlikely to pose a risk for pregnant or breastfeeding people or their babies. However, pregnant and breastfeeding people were not included in any of the clinical trials for currently authorized COVID-19 vaccines so there is little data on the safety of the vaccines in pregnant or breastfeeding people. Data show that while the overall risk for pregnant people with COVID-19 is low, they do have an increased risk of severe illness or death.
  • The Academy of Breastfeeding Medicine recommends that lactating individuals who get the vaccine continue breastfeeding their babies after being vaccinated. Breast milk contains antibodies and other components that can boost babies’ immune systems and protect babies from getting sick. Early research has shown COVID-19 antibodies are present in breast milk. It is believed that antibodies created after a breastfeeding individual receives the vaccine may also transfer into breast milk and could provide some protection to the baby.
  • For more information about COVID-19 vaccines and pregnancy, see CDPHE’s Pregnancy and breastfeeding FAQ.

  • Immunocompromised people may receive a COVID-19 vaccine if they have no reason to believe that getting the vaccine would be harmful to them. However, it is important to talk to your health care provider if you have questions about the unknown safety and effectiveness of the vaccine in immunocompromised populations, as well as the potential for reduced immune responses.

  • You will not be immediately protected from COVID-19 after receiving the vaccine. Studies show that it takes about two weeks after your last dose for your body to fully  protect itself against illness.

  • Scientists are working to learn more about COVID-19 variants. Early research suggests that the currently authorized vaccines are effective against the variants, though perhaps to varying degrees depending on the strain. Learn more about the COVID-19 variants

For more frequently asked questions about the vaccines, visit our FAQ page.

For more information on the COVID-19 vaccine, please call:

1-877-CO VAX CO (1-877-268-2926)
Available Monday through Friday, 8 a.m. to 8 p.m.;
Saturday and Sunday, 9 a.m. to 6 p.m.
Answers available in multiple languages.

The call center will be closed on Nov. 25, Dec. 25, and Jan. 1 for the holidays.