COVID-19 Vaccine Development and Planning

There are currently no authorized or approved vaccines to prevent COVID-19. There are a number of possible vaccines in development. The FDA must provide approval on the safety and efficacy of the vaccine before it is available to people not participating in clinical trials.

To ensure Colorado is ready when a vaccine is available, CDPHE is planning for a fair, equitable, and efficient COVID-19 vaccine distribution plan.

Colorado’s COVID-19 Vaccination Plan will evolve as more information about vaccines becomes available and stakeholder engagement continues. We will update this page as often as necessary when new information becomes available. 

9 things Coloradans should know about a COVID-19 vaccine

1. Like all vaccines, a COVID-19 vaccine must meet safety and effectiveness requirements set by the Food and Drug Administration (FDA) before it is made available to the general public.

Vaccines undergo a rigorous scientific process that requires three phases of clinical trials before they can be submitted to the FDA for approval. Learn more about the vaccine safety and development process in our FAQ below. 

In certain emergency situations, the FDA may issue an Emergency Use Authorization (EUA) to allow an investigational vaccine to be available to the general public. Read more about what that means in our FAQ below. 

2. There are several COVID-19 vaccines currently in development, but the FDA hasn’t authorized any yet. Colorado is prepared for many possibilities.

Our plan for vaccine distribution will depend on which available vaccine(s) the federal government sends to Colorado. We are preparing for many scenarios. We know that the distribution could involve new challenges like ultra-cold storage (-70 degrees) and special handling requirements. Colorado is working with many partners to plan for and distribute a vaccine when one is available.

3. Distributing a COVID-19 vaccine to the entire state will take time.

While we are planning to act swiftly, we expect it could take several months, or potentially more than a year, to distribute a vaccine to everyone who wants one, especially because most of the vaccine candidates require two doses. We are working closely with local public health agencies, health care providers, pharmacies, and diverse community partners to distribute the vaccine as equitably and efficiently as possible.

4. The state will distribute vaccines in phases until it is more widely available.

Because the initial supply of vaccine is expected to be very limited, it will be distributed first to people most at risk for COVID-19, such as health care workers, first responders, and staff/residents of long-term care facilities and nursing homes. The next stage will be people living in group settings, essential workers with a high level of interaction with other people, and higher risk populations more broadly. The final phase will be for the general population. 

Right now, children and pregnant women are not included in any phase because no vaccine candidates are currently being tested in pregnant women and only one candidate is being tested in children 12 years and older. We fully anticipate being able to vaccinate these populations once the FDA and CDC make the recommendation to do so.

Colorado’s phases are based on federal guidelines to distribute a limited supply of vaccines in a fair, ethical, and transparent way. See Colorado’s vaccine plan for more information about these phases.

5. Our vaccine distribution plan acknowledges the disproportionate impact COVID-19 has had on certain communities.

Everyone is affected by the COVID-19 pandemic in some way. But the burdens of the pandemic are not being experienced equally by all people. Colorado’s plan for distributing the vaccine considers systemic inequities that the virus has exploited. Prioritization accounts for social risk factors (such as working frontline jobs in close contact environments, less ability to work from home, and living in multi-generation or multi-family homes) that make some individuals more vulnerable to COVID-19. We have involved, and will continue to involve, communities that have been disproportionately affected by COVID-19 in our planning and implementation plans.

6. Cost will not be an obstacle to getting vaccinated against COVID-19.

As a condition of receiving free COVID-19 vaccines from the federal government, vaccine providers will not be allowed to charge patients for the vaccine. It is possible that providers may charge a fee to administer the vaccine. We expect that most public and private insurance companies will cover this fee so that there is no cost to the person getting vaccinated. This will also be the case for people without health insurance through the Provider Relief Fund, administered by the Health Resources and Services Administration (HRSA).

7. Administering the vaccine will be a joint effort between public and private partners.

So far, more than 1,200 facilities in Colorado have expressed interest in being a COVID-19 vaccine provider when a vaccine becomes available. During the initial phase, vaccine providers may include local public health agencies and large hospitals and health systems. As the vaccine becomes more widely available, the network of COVID-19 vaccine providers will expand to include doctors’ offices, pharmacies, homeless shelters, colleges/universities, senior centers, school-based health centers, and other health and medical locations. 

8. We cannot wait for a vaccine to slow the spread of COVID-19.

We have to continue to follow public health guidance closely now and for the foreseeable future. Prevention methods still include: wearing a mask in public, maintaining at least 6 feet of physical distance from others not in our household, avoiding large crowds, washing our hands often, and staying home when we are sick.

9. Getting a flu shot this year is more important than ever.

The flu vaccine is available now. The state health department recommends everyone age 6 months and older get the flu vaccine, as soon as possible. Getting a flu vaccine will not protect you from COVID-19, but a flu vaccination will reduce your risk of getting the flu. If you have questions about getting both the flu and COVID-19 vaccine when one is available, read our Flu vaccine and COVID-19 vaccine FAQ below or see our Similarities and Differences Between Flu and COVID-19 guidance.

Frequently Asked Questions


What is the purpose of Colorado's Vaccination Plan?

  • The purpose of Colorado's Vaccination plan is to prepare for COVID-19 vaccine distribution throughout the state. By doing extensive planning now, we hope to have a robust, efficient, and equitable vaccination process in place the moment a vaccine becomes available. 
  • The plan will also provide guidance to individual vaccine providers on who to vaccinate and when. The phased implementation of a COVID-19 vaccine is guidance to both the state and individual vaccine providers, but it is not a law or a mandate.

Who decided on the phases for vaccine distribution?

Colorado’s Phased Implementation Plan for a COVID-19 vaccine was developed through a collaboration between the Governor’s Expert Emergency Epidemic Response Committee’s Medical Advisory Group (a group of medical experts and ethicists), Colorado Department of Public Health and Environment (CDPHE), the Governor’s Office, and extensive community engagement with community members and leaders.

Flu Vaccine and COVID-19 Vaccine

Is there a COVID-19 vaccine right now?

No, there is not a COVID-19 vaccine available right now and we do not know when one will be available. Several COVID-19 vaccines are still under development, but none are approved yet. 

Who should get a flu vaccine?

Everyone age 6 months and older should get the flu vaccine annually, preferably by the end of October.

Why should I get a flu vaccine?

Getting a flu vaccine this fall is more important than ever because we need to ensure our  healthcare systems aren’t overwhelmed during the pandemic

Will a flu vaccine protect me against getting COVID-19?

Getting a flu vaccine will not protect you against COVID-19, but a flu vaccination will reduce your risk of getting the flu and being hospitalized because of the flu.

Am I more at risk of getting COVID-19 if I get a flu vaccine?

Vaccine Safety and Development

For additional information, visit CDC:

Who approves the use of vaccines in the United States?

The Food and Drug Administration (FDA) licenses and approves the use of vaccines. Before the FDA approves a vaccine, the manufacturer must do rigorous research and testing to ensure the vaccine’s safety and effectiveness. The FDA independently reviews and verifies the information from these tests. It then decides whether the vaccine can be given to the public. 

How are vaccines tested for safety and effectiveness?

Vaccines must go through a detailed scientific evaluation before they can be submitted to the FDA for approval. Each phase of the evaluation includes three different clinical research studies. In the clinical research study or trial, the vaccine is tested on people who volunteer to be part of the study. Each clinical trial emphasizes 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.

  • Phase 1 involves a small group of volunteers to evaluate safety and common side effects of the vaccine.
  • Phase 2 involves a larger group of volunteers to gather information on safety, vaccine dosing and how effective the vaccine will be in preventing the targeted disease.
  • Phase 3 involves the largest group of volunteers and a longer time frame than the earlier studies. Along with safety and side effects, most Phase 3 studies focus on efficacy -- how well the vaccine works -- and compare people who have received the vaccine to those who have not received the vaccine. This phase provides the most firm scientific evidence possible showing the difference between people who have been vaccinated and people who have not been vaccinated.

Who are the volunteers in in vaccine clinical trials?

  • The scientific community has made a concerted effort to recruit a diverse group of volunteers for every phase of COVID-19 vaccine trials. The goal is to test for safety and effectiveness in populations disproportionately impacted by COVID-19 disease and death, including Black/African American, Latino/a and American Indian/Alaska Native/Native Hawaiian communities. 
  • The COVID-19 Prevention Network (CoVPN) was formed by the National Institute of Allergy and Infectious Diseases (NIAID) at the U.S. National Institutes of Health to help address this issue. To read more about these efforts, visit

What happens after clinical trials are finished?

  • Once the clinical trials can demonstrate vaccine safety and effectiveness at an appropriate dose, the manufacturer applies to the FDA to license the vaccine so that it can be used in the general population. 
  • The FDA reviews all of the data from the phased clinical studies using rigorous protocols and procedures. The vaccine is not licensed or approved until the FDA can ensure the vaccine is safe and effective.
  • In emergencies, such as the current COVID-19 pandemic, vaccines can also be authorized through an Emergency Use Authorization (EUA).
  • Read the Emergency Use Authorization (EUA) FAQs below.

Who else reviews the safety and efficacy data from the clinical trials?

  • For each vaccine licensed by the FDA, the Advisory Committee on Immunization Practices (ACIP) carefully reviews all available data about the vaccine from clinical trials and other studies, and makes recommendations for vaccine use in the general public. Recommendations include groups that should and should not receive the vaccine, as well as the timing, volume, number, and spacing of doses in a vaccine series. 
    • The ACIP is a federal advisory committee that provides guidance on the best use of vaccines to the Centers for Disease Control and Prevention (CDC) and U.S. Department of Health and Human Services (HHS). 
  • Once ACIP recommendations have been reviewed and approved by the CDC and HHS, they are published in CDC’s Morbidity and Mortality Weekly Report (MMWR). The MMWR publication represents the final and official CDC recommendations for immunization of the U.S. population.

How is vaccine safety monitored after a vaccine has been approved or authorized?

  • FDA and CDC closely monitor vaccine safety after the public begins using the vaccine. There are four main vaccine safety monitoring systems:
    • Vaccine Adverse Event Reporting System (VAERS) - VAERS is an early-warning system that collects and analyzes reports of any problems that happen after vaccination. Anyone can submit a report, including parents, patients, and health care professionals.
    • Vaccine Safety Datalink (VSD) and Post-Licensure Rapid Immunization Safety Monitoring (PRISM) - VSD and PRISM are a collaboration between CDC and several health care organizations to actively monitor vaccines given to over 114 million people.
    • Clinical Immunization Safety Assessment Project (CISA) - CISA is a collaboration between CDC and seven medical research centers to answer complex safety questions. CISA conducts clinical research studies to further understand vaccine safety and recommend prevention strategies for adverse events following immunization.
  • Vaccine recommendations may change if safety monitoring reveals new information about vaccine risks, such as a new serious side effect. Safety alerts are sent to health care providers if there are any new problems. In some cases, a vaccine may be removed from the market. For example, in 1999, RotaShield®, a vaccine for rotavirus, was taken off the U.S. market after reports of increased cases of bowel obstructions in infants who had received the vaccine.

Emergency Use Authorization

What is an Emergency Use Authorization?

  • In certain emergency situations, the Food and Drug Administration (FDA) may issue an Emergency Use Authorization to provide more timely access to critical medical products when there are no other options available. An EUA permits the FDA to release unapproved medical products or allow for unapproved uses of medical products that have met certain criteria, to treat, diagnose, or prevent serious or life-threatening diseases.
  • The EUA process is different from the full approval process because in some emergency situations, we cannot wait for all the evidence needed for the full FDA approval. 
  • Instead, the FDA evaluates the risks and benefits of a product very quickly using the scientific evidence that is available.

Why do EUAs exist?

EUAs were initially introduced in 2004 to prepare for bioterrorism attacks. Under an EUA, the government is able to authorize medical treatments and products in the event of a Chemical, Biological, Radiological, and Nuclear (CBRN) attack.

What is the criteria for an EUA?

The FDA may issue an EUA for a medical product if it meets the following criteria:

  • The disease or CBRN agent in question can cause a serious or life-threatening illness or condition. 
  • There is reasonable belief, after looking at all the scientific evidence, that the product may be effective for its intended use. The phrase “may be effective” lowers the standards for scientific evidence typically required for FDA approvals.
  • The known and potential benefits outweigh the known and potential risks. The FDA will look at all available scientific evidence to determine the risk and benefits of a product. 
  • There is no adequate, approved, and available alternative to the product.

Is it common for vaccines to be authorized under an EUA?

A vaccine intended for wide distribution to the general public has never been released under an EUA. The only vaccine that has been authorized under an EUA so far was an anthrax vaccine in 2005. This vaccine was given to certain military personnel who were at heightened risk of exposure to anthrax.

When have EUAs been issued in the past?

Although not common, EUAs have been issued multiple times in the past for tests, treatments, and medical equipment.  

  • In 2009, EUAs were issued for diagnostic tests, personal protection equipment, and certain antiviral drugs during the H1N1 Swine Influenza pandemic.  
  • In 2013, EUAs were issued for diagnostic tests related to H7N9 influenza and Middle East Respiratory Syndrome (MERS). 
  • Several EUAs have already been issued for some COVID-19 tests and treatments: hydroxychloroquine, the antiviral medication remdesivir (recently approved), and convalescent plasma. However, the EUA for hydroxychloroquine was later withdrawn due to its lack of effectiveness in the treatment of COVID-19 and potential risk to patients.