Vaccines are one of the most effective ways of preventing serious illness or death from a variety of preventable diseases.
Getting annual and routine vaccinations at the right time helps protect you and your family against life-threatening diseases like polio, measles, RSV, and the flu.
Learn more about how vaccines work, when to get vaccines, and which vaccines to get.
Vaccines help your body respond better to illness by allowing your body to practice fighting off an infection. For some illnesses, vaccines can prevent any symptoms from developing. For other illnesses, vaccines can cause symptoms to be less severe.
When you receive a vaccine, your body receives dead or weakened germs. These germs cannot make you sick, but they give your body a chance to practice fighting off the germ. If you do feel sick after a vaccination, this means your immune system has responded to the vaccine and developed protection against future exposures to that germ. It could also mean that you are sick from a different germ, or you were exposed to the germ before you received the vaccine (see “Can I get sick after being vaccinated?” below). The next time your body is exposed to the germ you were vaccinated against from spending time with a sick person, or touching contaminated surfaces, your body is ready to fight off the infection.
All vaccines are required to undergo a process of extensive testing and approval to ensure the vaccine is both safe and effective at preventing illness. After a vaccine is approved for use, the CDC and FDA continue to monitor its safety.
Learn more about the ingredients contained in vaccines.
Some vaccines, like the flu, should be received every year. Other vaccines need to be received once or in a series and provide long-term protection. View the CDC’s Adult Immunization Schedule by Age to find out if you need any vaccines.
View the CDC’s full 2024 child and teen vaccine schedule to learn which vaccines your child needs.
Colorado law requires all students attending Colorado schools and licensed child cares to be vaccinated against certain diseases, unless an exemption is filed. Learn more about school requirements and vaccine exemptions.
Vaccine requirements for childcare and for entry to elementary school vary by age. View the full 2024 child and teen vaccine schedule.
It is possible to get sick with an illness after being vaccinated, but sickness after vaccines is not caused by the vaccination. After getting a vaccine, your body requires a period of days to weeks to create protection from that vaccine. It is possible to contract that illness after being vaccinated but before your body is immune. Also, you may have already been exposed to the illness in the days before getting vaccinated, but the symptoms may not start until after receiving the shot.
Vaccines do not prevent all illnesses. However, they have been shown to be one of the safest and most reliable methods to reducing the likelihood of contracting illness and reducing the severity of illness when contracted. Getting recommended flu, COVID-19, and RSV vaccines are a great way to reduce your risk of severe illness during respiratory season.
No. The most common COVID-19 vaccines in the U.S. use mRNA technology. These vaccines do not enter the nucleus of the cell where DNA is located. The vaccine cannot change your DNA.
No. The vaccine to prevent influenza may cause temporary symptoms of illness. You may experience soreness or redness where the shot was received, headache, fever, muscle aches, and fatigue. This indicates that your body is responding to the vaccine and developing protection in case you have contact with a person sick with the flu.
Protection against flu infection takes about 2 weeks to develop after receiving the flu vaccine. If you were exposed to the flu or another illness before your shot or in the 2 weeks following your shot, you may get sick since the vaccine was not yet effective.
Yes. RSV, flu and COVID-19 vaccines can be received during the same visit. Vaccines given with a needle at the same visit should be given at separate places on the body (at least one inch apart). Many routine vaccines are given at the same time. Check with your healthcare provider about specific vaccine administration questions.
Contact the Community Health team at the Douglas County Health Department at [email protected] for assistance with accessing vaccines.
