Vaccine Facts

COVID-19 basics

• COVID-19 can affect anyone. People of all ages can get COVID-19 — and many young people have died or developed serious health problems because of COVID-19.
• As of July 2021, more than 600,000 people have died from COVID-19 in the United States. In 2020, COVID-19 was the third leading cause of death in the United States after heart disease and cancer.
• COVID-19 has a wide range of symptoms. Some people have cold-like symptoms — like coughing, running a fever, or feeling tired and achy. Other people have more serious symptoms, like having trouble breathing or thinking clearly. Researchers are working to find out why some people get sicker than others.
• People can spread COVID-19 without having any symptoms. Some people with COVID-19 feel totally fine. But even if you don't feel sick, you can still spread the virus to other people.
• COVID-19 mainly spreads through the air. People with COVID-19 can spread the virus to other people around them when they talk, cough, sneeze, sing — or even just breathe.
• Some people develop long-term health problems from COVID-19 — called “long COVID.” Researchers are working to find out why this happens to some people who get COVID-19.
• You can get COVID-19 more than once. Researchers think that after you get COVID-19, you may have a short period of so-called “natural immunity” — but they're not sure how long it lasts.

COVID-19 vaccine basics

• The COVID-19 vaccines are very effective at preventing people from getting very sick. Vaccinated people are much less likely to go to the hospital or die from COVID-19.
• Vaccines work by training your immune system to recognize and fight off a specific germ before it has a chance to make you sick. Even if you already had COVID-19, getting vaccinated can help your immune system fight the virus better in the future.
• No vaccine is 100% effective. It's still possible for fully vaccinated people to get COVID-19, but unvaccinated people are at far higher risk.
• When you get a COVID-19 vaccine, you're not just protecting yourself. You're also protecting other people around you who are more likely to get very sick from COVID-19 — like older people, pregnant people, and people with disabilities or other health conditions.

COVID-19 vaccine development

• Clinical trials have proven that the COVID-19 vaccines are safe and effective. Tens of thousands of people from different races and ethnicities have participated in clinical trials to make sure the vaccines are safe — and that they work.
• The COVID-19 vaccine trials were randomized controlled trials — the gold standard for proving that vaccines work. Researchers in each trial gave one group of people a vaccine and another group a placebo (a shot with no vaccine in it). Then they compared how many people in each group got COVID-19. Based on these trials, researchers learned that fully vaccinated people are much less likely to get COVID-19.
• Experts around the world worked together to develop the COVID-19 vaccines quickly and safely. The development process was fast because international researchers, scientists, and government agencies worked together in new ways to put an end to the pandemic. They didn't skip any safety steps.
• Scientists have been working on the mRNA technology used in the Pfizer and Moderna vaccines for more than 20 years. These vaccines work by delivering a small strip of genetic code (the mRNA) that teaches your immune system to protect against a key protein — in this case, the spike protein on the surface of the COVID-19 virus.

Vaccine side effects

• It's normal to have some side effects — like feeling tired and achy — for a day or 2 after getting vaccinated. These side effects are signs that your body is building up protection, and that means the vaccine is working.
• There's no evidence that COVID-19 vaccines can affect your ability to have kids.
• Researchers haven't found any long-term side effects from COVID-19 vaccines.
• You can't get COVID-19 from a vaccine. The vaccines teach your body to fight off COVID-19. There’s no live COVID-19 virus in the vaccines, so they can't give you COVID-19.

COVID-19 variants

• Variants are new versions of COVID-19. Some variants spread more easily, and some may cause more serious health problems.
• Getting a COVID-19 vaccine is the best way to protect yourself from variants. Fully vaccinated people are less likely to get very sick, go to the hospital, or die from any type of COVID — including the variants.
• When more people get vaccinated, it's harder for new variants to form. That's because the COVID-19 virus needs to infect someone before it can change into a new variant, and vaccinated people are less likely to get infected.

• Vaccines for COVID-19 Centers for Disease Control and Prevention
• COVID-19 Vaccine Guidance Mayo Clinic
• COVID-19 Vaccines National Institutes of Health