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Viruses are a kind of germ. There are millions of viruses in the world, but only a small number of them can make people sick. Our bodies learn to recognize viruses and other germs, then our bodies develop ways to fight the germs.

What Viruses Are Not Very Serious?

Many viruses usually don’t make people very sick. This includes the ones that cause common colds. But a virus can affect people differently depending on their age, overall health and other factors.

What Viruses Are Very Serious?

For young babies, even a cold virus can be serious. When your baby is 3 months or younger, call their doctor if they seem sick.

The flu, measles, whooping cough and chickenpox are diseases caused by viruses. These diseases can have long-term health effects or cause death. But all of these diseases can be prevented with vaccines.

Avoid Spreading Viruses

  • Cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your hands.
  • Avoid sharing cups and eating utensils with others.
  • Clean frequently touched surfaces, like doorknobs and cell phones.
  • Stay home if you are sick.

You can avoid catching or spreading viruses by washing hands often with soap.

About COVID-19

COVID-19 is the illness caused by a virus called SARS-CoV-2. People started getting sick with this virus in late 2019. COVID-19 can spread very easily, partly because some people’s bodies don’t recognize the virus. COVID-19 makes some people very sick, and some people die from it. There are ways to avoid spreading COVID-19, and vaccines and treatments are available.


More Ways to Find Help

Arizona Department of Health Services COVID-19 Information Information about vaccines, testing and cases in Arizona.

Arizona 2-1-1 COVID-19 Information Help with COVID-19 testing, vaccines and medical expenses.

Germs: Bacteria, Viruses, Fungi, and Protozoa Information about viruses and other germs.


The First Things First Parent Kit was developed in partnership with Health Research for Action/UC Berkeley. © 2023 The Regents of the University of California. Additional video, graphic and other content © 2023 First Things First. All rights reserved.

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