Prevention

The U.S. Food and Drug Administration (FDA) has given emergency use authorization to some COVID-19 vaccines in the U.S. The FDA has approved the Pfizer-BioNTech COVID-19 vaccine, now called Comirnaty, to prevent COVID-19 in people age 16 and older. A vaccine can prevent you from getting the COVID-19 virus or prevent you from becoming seriously ill if you get the COVID-19 virus. In addition, COVID-19 vaccination might offer better protection than getting sick with COVID-19. A recent study showed that unvaccinated people who already had COVID-19 are more than twice as likely as fully vaccinated people to get reinfected with COVID-19.

Also, if you are fully vaccinated, you can return to many activities you may not have been able to do because of the pandemic — including not wearing a mask or social distancing — except where required by a rule or law. However, if you are in an area with a high number of new COVID-19 cases in the last week, the CDC recommends wearing a mask indoors in public and outdoors in crowded areas or when you are in close contact with unvaccinated people. If you are fully vaccinated and have a condition or are taking medications that weaken your immune system, you may need to keep wearing a mask.

An additional dose of a COVID-19 vaccine is recommended for people who are fully vaccinated and might not have had a strong enough immune response. In contrast, a booster dose is recommended for people whose immune response weakened over time.

The CDC recommends additional doses and booster doses of COVID-19 vaccines in specific instances:

• Additional dose. The CDC recommends a third dose of an mRNA COVID-19 vaccine for some people with weakened immune systems, such as those who have had an organ transplant. People with weakened immune systems might not develop enough immunity after vaccination with two doses of an mRNA COVID-19 vaccine. An additional dose might improve their protection against COVID-19.

  The third dose should be given at least 28 days after a second dose of an mRNA COVID-19 vaccine. The additional dose should be the same brand as the other two mRNA COVID-19 vaccine doses you were given. If the brand given isn�t known, either brand of mRNA COVID-19 vaccine can be given as a third dose.

• Booster dose. The CDC recommends a booster dose of the Pfizer-BioNTech COVID-19 vaccine for people age 65 and older, residents in long-term care settings and people ages 50 to 64 who have underlying medical conditions, such as cancer, diabetes and heart disease. A booster dose of the Pfizer-BioNTech COVID-19 vaccine is also available to people ages 18 to 49 with underlying medical conditions and people ages 18 to 64 who have a job that puts them at increased risk of being exposed to COVID-19.

  The booster dose should be given at least 6 months after the second dose of the Pfizer-BioNTech COVID-19 vaccine.

There isn�t enough research to determine if people with weakened immune systems who got a Janssen/Johnson & Johnson COVID-19 vaccine also have an improved response after getting an additional dose of the same vaccine. The CDC also hasn�t made recommendations about booster doses for people who got the Moderna or Janssen/Johnson & Johnson COVID-19 vaccine.

If you haven�t had the COVID-19 vaccine, you can take many steps to reduce your risk of infection. WHO and CDC recommend following these precautions for avoiding exposure to the virus that causes COVID-19:

• Avoid close contact (within about 6 feet, or 2 meters) with anyone who is sick or has symptoms.
• Keep distance between yourself and others (within about 6 feet, or 2 meters). This is especially important if you have a higher risk of serious illness. Keep in mind some people may have COVID-19 and spread it to others, even if they don't have symptoms or don't know they have COVID-19.
• Avoid crowds and indoor places that have poor ventilation.
• Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer that contains at least 60% alcohol.
• Wear a face mask in indoor public spaces and outdoors where there is a high risk of COVID-19 transmission, such as at a crowded event or large gathering. Further mask guidance differs depending on whether you are fully vaccinated or unvaccinated. Surgical masks may be used if available. N95 respirators should be reserved for health care providers.
• Cover your mouth and nose with your elbow or a tissue when you cough or sneeze. Throw away the used tissue. Wash your hands right away.
• Avoid touching your eyes, nose and mouth.
• Avoid sharing dishes, glasses, towels, bedding and other household items if you're sick.
• Clean and disinfect high-touch surfaces, such as doorknobs, light switches, electronics and counters, daily.
• Stay home from work, school and public areas if you're sick, unless you're going to get medical care. Avoid public transportation, taxis and ride-sharing if you're sick.

If you have a chronic medical condition and may have a higher risk of serious illness, check with your doctor about other ways to protect yourself.

Travel

If you're planning to travel, first check the CDC and WHO websites for updates and advice. Be prepared to wear a mask and use appropriate hand hygiene when in public. You may also want to talk with your doctor if you have health conditions that make you more susceptible to respiratory infections and complications.