COVID-19 Vaccine Information & FAQs

A Pfizer of Moderna COVID-19 is preferred, especially if you are immunocompromised. You should get the first vaccine offered to you to better protect yourself and those close to you. Pfizer, Moderna, and Johnson & Johnson are all highly effective at preventing critical illness, hospitalization, and death due to COVID-19.

For additional questions about where you can receive the vaccine or who to contact in your community, call COHELP (1-877-462-2911).

The Johnson & Johnson vaccine is a viral vector vaccine given as a single dose.

The Pfizer and Moderna vaccines are an mRNA vaccine with two doses.

They all are extremely adequate at preventing hospitalizations and deaths due to COVID-19, an important step in ending the pandemic.

All of the Emergency Use Authorized and Approved vaccines have been deemed safe by the FDA and do not contain any metals or preservatives.

Pfizer-BioNTech (Comirnaty): mRNA, lipids ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3-phosphocholine, and cholesterol), potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, and sucrose. The pediatric formulation for ages 5-11 contains a tromethamine/sucrose formulation instead of a phosphate-buffered saline/sucrose formulation for improved vaccine stability.

Moderna: Messenger ribonucleic acid (mRNA), lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]), tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate, and sucrose

Janssen/Johnson & Johnson: Replication-incompetent adenovirus vector expressing the SARS-CoV-2 spike protein and a variety of salts, buffers, and sugars that help stabilize it (citric acid monohydrate, trisodium citrate dehydrate, ethanol, 2-hydroxypropyl-beta-cyclodextrin, polysorbate 80, sodium chloride, sodium hydroxide, hydrochloric acid).

Even though you may be fully vaccinated, you could still carry and spread the COVID-19 virus. It is important to continue distancing and mask-wearing until more is known about the spread of COVID-19 with a vaccine.

Pfizer: has reported that their vaccine is 95% efficacy 14 days after the second dose (35 days after receiving the first dose)

Moderna has reported that their vaccine is 94.5% effective 14 days after the second dose (42 days after receiving the first dose)

Johnson & Johnson: has reported that their vaccine is approximately 66% effective (up to 72% effective in the United States) 28 days after the first dose.

A COVID-19 vaccine will give you protection against the disease without having to get sick with the actual virus. It is not possible to get COVID-19 from a vaccine, but it is possible to get symptoms that are consistent with COVID-19. The vaccine candidates use an inactivated virus, parts of the virus (e.g., the spike protein), or a gene from the virus. None of these can cause COVID-19. The goal of the vaccine is to provide your body with the tools it needs to fight the COVID-19 virus if you were to get infected.

The COVID-19 vaccine should not be given simultaneously with any other vaccines during pregnancy. Wait a minimum of 14 days before and after the administration of other vaccines before getting the first and second dose of COVID-19 vaccine.

For more information about COVID-19 vaccines and pregnancy, see CDPHE’s Pregnancy and breastfeeding FAQ.

Yes, you are at higher risk of severe COVID-19. Information about safety in this specific group is not yet available, so please be aware of potential for reduced immune response to the vaccine.

Yes. If you have a history of allergic reactions not related to vaccines or injectable medications (such as foods, pets, bee stings, environmental, latex, etc.) you should get vaccinated. If you have a history of allergic reactions to any ingredient in the COVID-19 vaccines or a history of severe allergic reactions to other vaccines, you should talk with your provider prior to getting vaccinated.

Yes. Re-infection with COVID-19 is possible and has been seen. However, current evidence suggests reinfection is uncommon in the 90 days after initial infection and thus people with documented acute infection in the preceding 90 days may defer vaccination until the end of this period, if desired.

Most people who received the mRNA vaccines in clinical trials experienced mild to moderate side effects that typically went away on their own after a few days. The most commonly reported side effects for the Pfizer and Moderna COVID-19 vaccines are pain, swelling, and redness at the injection site; pain, tenderness and swelling of the lymph nodes in the same arm of the injection; and fatigue, headache, muscle pain, chills, joint pain, nausea/vomiting, and fever for a few days after receiving the vaccine, with more pronounced discomfort after the second dose. The frequency and severity of side effects may vary between the two vaccines. Different people may experience different side effects, even if they receive the same vaccine.

The process of building immunity can cause symptoms. These symptoms are normal and show that your body’s immune system is responding to a vaccine. Other routine vaccines, like the flu vaccine, have similar side effects.

If you experience discomfort after the first dose of the vaccine, it is very important that you still receive the second dose a few weeks later for full protection.

For in-depth information about the side effects of the vaccines, see the CDC’s report on the Pfizer vaccine and the Moderna vaccine.

It will take time after the vaccination for your body to respond and make enough antibodies to protect you. This could take up to one to two weeks after your last dose.

Vaccinated individuals are still required to abide by businesses and other organizations that require masking for all.

An antibody is a protein produced by your immune system that can recognize a specific type of virus in your body. When you get infected, your body’s antibodies are able to recognize proteins on the surface of the COVID-19 virus to attack and stop it from replicating in your body.

For a visual explanation of how mRNA vaccines work, watch Stat’s video “What are mRNA vaccines?”

To learn more, visit the CDC’s Understanding How COVID-19 Vaccines Work.

To learn more, visit the CDC’s Understanding How COVID-19 Vaccines Work.

Yes. After enough research, the CDC has changed its recommendation to allow co-administration of the COVID-19 vaccine with other vaccines. If more than one vaccine is administered at a time, it should be in a different location.

Vaccinated persons with an exposure to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria:

• Are fully vaccinated (has received both doses and it’s been 2 weeks following administration of the second dose in a 2-dose series)
• Are within 3 months following receipt of the last dose in the series
• Have remained asymptomatic since the current COVID-19 exposure

If you have been given a quarantine order in Larimer County and you are fully vaccinated, please complete this form so they can follow-up.

Studies are ongoing. Early evidence shows that the Moderna and Pfizer vaccine should still provide protection, although may be slightly less effective against the new variants. The Johnson and Johnson vaccine has shown protection against the South Africa and UK variants at this time.

On August 12, the FDA modified the EUA for Pfizer-BioNTech and Moderna COVID-19 vaccine to allow for a 3rd dose of mRNA COVID-19 for those who are fully vaccinated that are moderately to severely immunocompromised.

EUA is a process that allows use of a product (immunization, medication, medical device) in an emergency. It is similar to FDA approval in that it requires evidence to show that benefits outweigh potential risks. At any point, an EUA can be revised or revoked by the FDA as more data becomes available. FDA approval requires a greater amount of evidence to show that the product (in this case the immunization) is safe and effective for its intended use and that the product can be made according to federal quality standards.

The amendment applies to the age ranges for which both vaccines are approved for:

• Pfizer-BioNTech COVID-19 Vaccine: Ages > 12 years old
• Moderna COVID-19 Vaccine: Ages > 18 years old

Those with medical conditions or people receiving treatments that are associated with moderate to severe immune compromise, including:

• Active or recent treatment for solid tumor and hematologic malignancies
• Receipt of solid-organ or recent hematopoietic stem cell transplants
• Severe primary immunodeficiency
• Advanced or untreated HIV infection
• Active treatment with:
  • High-dose corticosteroids
  • Alkylating agents
  • Antimetabolites
  • Tumor-necrosis (TNF) blockers
  • Other biologic agents that are immunosuppressive or immunomodulatory
• Chronic medical conditions such as asplenia and chronic renal disease may be associated with varying degrees of immune deficit

You should try to get the same vaccine (Pfizer or Moderna) that you got from your primary series. If for some reason that is not feasible, a dose of the other mRNA vaccine is permitted.If your initial dose was Johnson & Johnson, it is recommended that your additional dose be an mRNA vaccine.

It is recommended that people who are moderately or severely immunocompromised should receive an additional dose using an mRNA COVID-19 vaccine at least 4 weeks after the 1st dose.

There is emerging data showing immunocompromised people who have low or no protections following two doses of mRNA COVID-19 vaccines may have improved response after an additional dose of the same vaccine.

Guidance suggests at least 28 days (4 weeks) after you receive the second dose of the original vaccine series.

So far reactions reported after the third mRNA dose were similar to that of the two-dose series including the two most common: pain at the injection site and fatigue. Most symptoms were mild to moderate.

Yes, this vaccine is the same and covers the same strains as the first two doses in the series.    

Not at this time. Vaccines under the Emergency Use Authorization are paid for by the government. 

Immunocompromised are more likely to get breakthrough infections than people with healthy immune systems due to not mounting an adequate immune response to the initial two doses. The additional dose has been shown to improve the immune response in this population.

At this time, you do not require a doctor’s note. Check the Colorado COVID-19 vaccine site to find where you can get your vaccine

Updated 12/28/21 – The CDC and ACIP now recommend the mRNA COVID-19 vaccines (Pfizer and Moderna) over the J&J COVID-19 vaccine. The unanimous recommendation followed a robust discussion of the latest evidence on vaccine effectiveness, safety, rare adverse events, and consideration of the US vaccine supply. This updated CDC recommendation follows similar recommendations from other countries, including Canada and the United Kingdom. The ACIP does state that receiving any vaccine is better than being unvaccinated, thus will still have access to the J&J COVID-19 vaccine.

A single booster dose has been authorized for the Pfizer-BioNTech COVID-19, Moderna COVID-19, and J&J/Janssen COVID-19 vaccines via an amendment to their Emergency Use Authorization (EUA).

The Moderna COVID-19 booster has been authorized 5 months after the initial vaccination series for all individuals 18 years of age or older.

The Pfizer COVID-19 booster has been authorized 5 months after the initial vaccination series for all individuals 12 years of age or older.

The J&J/Janssen COVID-19 booster has been authorized 2 months after the initial dose for anyone 18 years of age and older.

On August 23, 2021, the FDA approved the Pfizer-BioNTech COVID-19 vaccine, Comirnaty (koe-mir’-na-tee,).  Comirnaty is approved for the prevention of COVID-19 disease in individuals 16 years of age and older.  The ingredients/formulation has not changed, and the vaccine will still be administered as a 2 dose series, 3 weeks apart.

The vaccine continues to be available under emergency use authorization (EUA) for ages 12-15 and for the administration of a third dose in certain immunocompromised individuals.

Yes, the dose of the Pfizer COVID-19 vaccine (Comirnaty) is the same as the initial vaccine series.

Side effects are similar to those seen with initial vaccine series. The most common side effects are injection site soreness, fatigue, headaches, and muscle pain.

The following conditions put you at higher risk of severe COVID-19. If you are unsure if you are eligible for a booster, please talk with your doctor.

•         Cancer
•         Chronic kidney disease
•         Chronic lung disease (COPD, moderate to severe asthma, interstitial lung disease, cystic fibrosis, pulmonary hypertension)
•         Dementia or other neurological conditions
•         Diabetes (type 1 or type 2)
•         Down syndrome
•         Heart conditions (heart failure, coronary artery disease, cardiomyopathies, hypertension)
•         HIV infection
•         Immunocompromised state (due to disease state or medication)
•         Liver disease
•         Obesity
•         Pregnancy
•         Sickle cell disease or thalassemia
•         Smoking tobacco use, current or former
•         Solid-organ or blood stem cell transplant
•         Stroke or cerebrovascular disease
•         Substance use disorder

If you just recently received the two first doses in the vaccine series or received the J&J vaccine, you are considered fully vaccinated. These recommendations may change as more data becomes available.

COVID-19 booster vaccines continue to be available under EUA for individuals 18 years old and older in eligible populations.

Available data right now shows that all three of the COVID-19 vaccines approved or authorized in the United States continue to be highly effective in reducing risk of severe disease, hospitalization, death and even against the widely circulating delta variant. Vaccination remains the best way to protect yourself and reduce the spread of the virus and help new variants from emerging.

The FDA has authorized the use of a heterologous (or “mix and match”) booster dose for currently available COVID-19 vaccines. A single booster dose of Pfizer, Moderna, or J&J/Janssen may be administered as a booster dose following completion of primary vaccination.

You can receive a booster of the Pfizer or Moderna COVID-19 vaccine at least 5 months after completion of your primary vaccination series.

You can receive a booster of the J&J/Janssen COVID-19 vaccine at least 2 months after completion of the primary vaccination.

The Moderna booster has been authorized as half of the dose of the initial series.

No, pediatric dosing consists of a dose that is 1/3 of that of the 12 years and older dose. It consists of a primary series of two 10 mcg (0.2 mL) doses, 21 days (3 weeks) apart.

Regulators concluded that the vaccine’s protective benefits clearly outweigh its risks.

Rates of adverse reactions in children 5-11 years of age were generally similar to those in individuals 12 years of age or older. Pain at the injection site was lower in the 5-11 year old group, but redness and swelling was slightly higher. Systemic adverse reactions such as fever, fatigue, headache, chills and muscle pain were generally reported less frequently and were milder in severity in the 5-11 year-old group compared to individuals 12 years of age or older.

The Pfizer vaccine formulation for individuals 12 years of age and older consists of Phosphate-buffered saline/Sucrose formulation. Pfizer vaccine formulations for individuals 5 through 11 years of age consists of Tromethamine/Sucrose formulation. 

According to the CDC, no cases of myocarditis or pericarditis were reported in clinical trials for children ages 5-11 years (n=3,082). However, the study was not powered to assess the risk of myocarditis. The baseline of myocarditis is much higher in adolescents ages 12-17 years compared to children ages 5-11 years. The observed risk highest for myocarditis is observed in males 12 through 17 years of age. Overall, the benefits of the vaccine would outweigh its risk in children 5 through 11 years of age.

Vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the Omicron variant, just as they did with the Delta variant. However, breakthrough infections in those that are fully vaccinated will likely occur. The emergence of the Omicron variant emphasizes the importance of vaccination and boosters.

At this time, the only people authorized to receive four doses of the COVID-19 vaccine are those that are considered moderately to severely immunocompromised. If you fall into one of the below categories, it is recommended you receive a third dose as part of your primary series, 28 days following your second dose (Moderna and Pfizer only). It is recommended that these patients also get a booster dose (fourth dose) 5 months following their initial vaccine series. 

Examples of medical conditions or treatments that are associated with moderate to severe immune system compromise include:

• Active or recent treatment for solid tumor and blood cancers
• Receipt of solid-organ or recent stem cell transplants
• Severe primary immunodeficiency
• Advanced or untreated HIV infection
• Active treatment with the following types of medications
  • High-dose steroids (ex:> 20mg of prednisone or equivalent daily for more than 2 weeks)
  • Alkylating agents (ex: cisplatin, cyclophosphamide, carboplatin)
  • Anti-metabolites (ex: methotrexate, hydroxyurea, 6-mercaptopurine, 5-fluorouracil, cytarabine)
  • Tumor-necrosis (TNF) blockers (ex: infliximab/Remicaide, etanercept/Enbrel, adalimumab/Humira)
  • Other biologic agents that are immunosuppressive or immunomodulatory
• Chronic medical conditions such as asplenia and chronic renal disease may be associated with varying degrees of immune deficit

On January 31, 2022 the FDA approved the Moderna COVID-19 vaccine, Spikevax.  Spikevax is approved for the prevention of COVID-19 disease in individuals 18 years of age and older.  The ingredients/formulation has not changed, and the vaccine will still be administered as a 2 dose series, 4 weeks apart.   

The vaccine continues to be available under the FDA Emergency Use Authorization (EUA) as a third primary series dose for individuals 18 years of age and older who have been determined to have certain kinds of immunocompromise, and as a single booster dose for individuals 18 years of age and older at least 5 months after completing a primary series of the Moderna COVID-19 Vaccine or Spikevax. 

Yes. Having a history of Myocarditis or Pericarditis does not mean you should not receive an mRNA vaccine. However, if you start developing symptoms of Myocarditis or Pericarditis after the first dose, you should not get the second dose of the mRNA vaccine. If you have questions or concerns, consult with your provider before getting a COVID-19 vaccine.

Visit covid19.colorado.gov/vaccine-faq for more information from the CDPHE.