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Is it safe? Learn how vaccines are made, tested and monitored

| Healthy You | Wellness

White haired woman in face mask has bandage applied to her arm by a healthcare provider in blue gloves and surgical gown after getting a shot or vaccine

By the time it gets to you, a vaccine will have been tested on thousands of people.

Staying current with the vaccines your doctor recommends is one of the most effective ways to protect yourself and your family from common illnesses.

But you may have questions about how vaccines work — or wonder if they’re safe. Here’s a look at how they’re created, tested and monitored for safety.

How do vaccines work?

When germs like a cold or flu virus get into your body, your immune system works to protect you from infections. Unfortunately, some germs are hard to beat without help. That’s where vaccines come in.

“Getting vaccinated is a quick, safe and easy way to lower your chances of getting sick,” says Bob Pelz, MD, PeaceHealth’s system medical director of Infection Prevention.

Most vaccines work by injecting tiny amounts of a substance called an antigen into your body. Antigens “teach” your immune system how to protect against the substance they’re made from — in this case, the germs that make you sick.

Other vaccines work without antigens. Both kinds help people lower their risk of serious illnesses. This explainer from the World Health Organization can help you see how.

Are vaccines safe?

By the time it reaches you, a vaccine will have gone through many stages of scientific testing for safety and effectiveness. It can take up to 15 years and tests with thousands of people to get a vaccine approved. And when it’s in use, the federal government carefully monitors its performance over time.

This is why health experts say the risk of getting sick when unvaccinated is much higher than the risk of having a serious reaction to a vaccine. Sticking to a vaccine schedule also limits the chances that you'll pass illnesses to friends, coworkers and vulnerable members of your community.

At any age or stage, “vaccines are proven to be the best way to protect ourselves and reduce the likelihood of harming others,” says Dr. Pelz.

In fact, the World Health Organization says vaccines are the most significant global health advancement in the past 50 years. In that timeframe, vaccines have saved 154 million lives. That's equal to six lives every minute of the last half century. People who were vaccinated as babies gain an average of 66 years of health as a result, WHO researchers say.

If you have questions about vaccine safety, have an honest conversation with your healthcare provider. They can explain how vaccines are tested and what you can expect with the ones recommended for you or your family, including any side effects.

Together you can create a plan to stay current with the vaccines you and your family need to protect your health.

portrait of Robert K. Pelz MD

Robert K. Pelz MD

Infectious Diseases
Critical Care Medicine
Internal Medicine
Undersea and Hyperbaric Preventive Medicine
In addition to an MD he has a PhD in clinical research from Johns Hopkins School of Public Health, and he was fellowship trained in critical care medicine at the NIH. Prior to joining PHMG in 2002 Dr. Pelz practiced infectious disease and critical care medicine in Everett, Wash. Dr. Pelz is serving both as a hyperbaric medicine specialist at Riverbend and as an infectious disease specialist. His practice is open to new HIV patients as well as infectious disease consultations. He is eager to assist the medical community with infectious disease consultations, and management of chronic infectious diseases, including HIV and hepatitis.