CDC tool shows how to improve airflow during indoor gatherings

The U.S. Centers for Disease Control and Prevention wants to show Americans how they can improve airflow and reduce COVID-19 transmission during an indoor gathering. 

The agency rolled out the interactive tool Wednesday as millions of Americans are set to congregate for the Thanksgiving holiday.

"If a guest visits your home, improving ventilation (air flow) can help prevent virus particles from accumulating in the air," the agency continued. "Good ventilation, along with other preventive actions, like staying 6 feet apart and correctly wearing masks, can help prevent you from getting and spreading COVID-19."

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The website provides multiple drop-down menus. First, users can select which mode they want to operate their HVAC unit: off, auto or on. Next, users can select a premium or regular filter. Then, users can choose if they have or don’t have HEPA Air Cleaner. Finally, users can then select if they have or don’t have a nearby window open.

Based on the selections, the CDC will display a meter showing if users have poor ventilation inside their home or improved ventilation. The map will also display animated particles to show how far apart or close they are based on the user’s selections. 

"Small particles that people breathe out can contain virus particles, including the virus that causes COVID-19," the agency also posted on its website. 

The CDC recommends avoiding crowded, poorly ventilated spaces, if possible.

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The CDC also suggests wearing well-fitting masks over your nose and mouth if you are in public indoor settings and not fully vaccinated. Even those who are fully vaccinated are asked to wear a mask in public indoor settings in areas with substantial to high transmission. The agency said you might choose to wear a mask regardless of the level of transmission if a member of your household has a weakened immune system, is at increased risk for severe disease, or is unvaccinated.

The CDC also said the best way to minimize COVID-19 risk and keep your friends and family safer is to get vaccinated against the novel coronavirus. By getting a vaccine, the CDC says recipients will better protect those not yet eligible for vaccination, such as young children under the age of 5.

Dr. Anthony Fauci, the country’s top infectious disease expert, said that families who are fully vaccinated against COVID-19 should "feel good" about gathering for the holidays this year.

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"If you get vaccinated and your family's vaccinated, you can feel good about enjoying a typical Thanksgiving, Christmas with your family and close friends," he said, adding, "When you're with your family at home, goodness, enjoy it with your parents, your children, your grandparents. There's no reason not to do that."

If you are considering traveling for a holiday or event, visit the CDC’s travel page to help you decide what is best for you and your family. The CDC still recommends delaying travel until you are fully vaccinated.

If you are not fully vaccinated and must travel, follow CDC’s domestic travel or international travel recommendations for unvaccinated people, but keep in mind that many countries may bar unvaccinated travelers from entry. If you are not fully vaccinated, the CDC recommends getting tested with a viral test 1-3 days before your trip.

Everyone, even people who are fully vaccinated, is required to wear a mask on public transportation in the U.S.

If you are sick or have symptoms, don’t travel, host or attend a gathering, and get tested if you have symptoms of COVID-19 or have a close contact with someone who has COVID-19.

Stephanie Weaver contributed to this report. This story was reported from Los Angeles.