COVID-19 Vaccines Facts

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8

3 Types of COVID-19 Vaccines

It takes about 2 weeks after your final dose for your body to be fully protected against COVID-19 illness. COVID-19 vaccines protect people against severe illness, including disease caused by other variants circulating in the U.S.

COVID-19 Vaccines for Children 6 months and older

Pfizer's pediatric COVID-19 vaccine is authorized for use in children 6 months and older. CDC recommends that all children older than 5 years old get vaccinated to help protect against COVID-19. 

  • Vaccinating children can help protect family members, including siblings who are not eligible for vaccination and family members who may be at increased risk of getting very sick if they are infected.
  • Vaccination can also help keep children from getting seriously sick even if they do get COVID-19.
  • Vaccinating children ages 5 years and older can help keep them in school and help them safely participate in sports, playdates, and other group activities.

Learn more from CDC about the pediatric COVID-19 vaccine, including safety information. 

Booster Dose

CDC advises people should receive a booster dose from a COVID-19 vaccine provider if they are age 12 and older and:

  • it has been 5 months since their last dose of Pfizer or Moderna vaccine or
  • it has been 2 months since they received a Johnson & Johnson vaccine

2nd Booster Dose

On May 19, 2022, CDC strengthened its recommendation that those aged 12 years and older who are immunocompromised and those aged 50 years and older should receive a second booster dose at least four months after their first. Over the past month, there has been a steady increase in cases in the United States, with a steep and substantial increase in hospitalizations for older Americans. While older Americans have the highest coverage of any age group of first booster doses, most older Americans received their last dose (either their primary series or their first booster dose) many months ago, leaving many who are vulnerable without the protection they may need to prevent severe disease, hospitalization, and death. Read the full CDC guidance 

The following people should receive a second booster dose using an mRNA (Pfizer or Moderna) COVID-19 vaccine at least four months after their first booster dose:

  • People aged 50 years and older.
  • People aged 12 years and older who are moderately or severely immunocompromised.
  • People aged 18 years and older who received J&J COVID-19 vaccine as both a primary and a booster dose

Side Effects

Side effects usually start within a day or two and go away in a few days. It is normal to have side effects and is a sign of your immune system learning to fight the virus.

Common Side Effects

  • Pain, redness, or swelling in the arm where you got the shot
  • Tiredness, headache, muscle pain, chills, fever, or nausea.

Natural Immunity

If you have been infected with COVID-19, you should still get vaccinated. Immunity varies from person to person and you could still get the virus again. For example, studies show that some infected people with mild disease or no symptoms have low levels of antibodies. Unvaccinated people who got sick with COVID-19 then get vaccinated, have a strong response to vaccine and higher protection. 

Additional COVID-19 Vaccine Resources

  • CDPHE's Learn about COVID-19 Vaccines
  • State's vaccine call center at 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 are available in multiple languages.
  • CDC's Key Things to Know

Emergency Use Authorizations for COVID-19 Vaccines