UC Davis infectious disease experts weigh in on common novel coronavirus (COVID-19) mistakes and myths and give the science behind them.


older man getting a COVID-19 vaccine

You will not get COVID-19 from the vaccines

There's no way to get COVID-19 from the vaccines. None of the vaccines that were given emergency-use authorization by the FDA in the U.S. use a live virus. The Pfizer and Moderna vaccines use messenger ribonucleic acid (mRNA), which carries instructions to your body about how to build a protein. In this case, it’s telling your body to make the spike protein that’s on the novel coronavirus. As a result, your immune system remembers the protein and is ready to attack and eliminate the real SARS-CoV-2 virus.

Learn more about how COVID-19 vaccines work


test tube with positive COVID-19 result

Breakthrough cases for vaccinated people are rare, but do happen

When a vaccinated person tests positive for COVID-19, most either have no symptoms or have very mild symptoms, and it rarely results in hospitalization or death. Their symptoms are more like those of a common cold, such as cough, fever or headache, with the addition of significant loss of smell.

As of July 22, there were 65,000 breakthrough cases (or people who are vaccinated but got COVID-19) among the 160 million people who are fully vaccinated. That's 0.04% of vaccinated people reporting breakthrough cases. No vaccine is 100% effective. With the COVID-19 vaccines averaging about 90% efficacy, health experts expect about 10% of those vaccinated could be infected.

Learn how to schedule your COVID-19 vaccine at UC Davis Health


hand touching door handle

Contaminated surfaces aren't the highest COVID-19 risk

The primary route of COVID-19 infection isn't by touching contaminated surface but through the respiratory system, said Dean Blumberg, chief of pediatric infectious disease at UC Davis Children's Hospital. People should focus on wearing masks and social distancing and less on sanitizing surfaces.

Tests have found traces of COVID-19 on surfaces, but no research has established that the virus is viable in those places, partly because research has veered in other directions.


wiping table with cleaning product

Cleaners need at least 1 minute to disinfect

Many people are unaware that most cleaning products should stay wet on a surface for at least one minute, potentially up to 10 minutes, before wiping it down, according to Natascha Tuznik, a UC Davis Health assistant clinical professor of infectious diseases.

Learn more about contact time of a cleaner from the Environmental Protection Agency's List N Tool: COVID-19 Disinfectants


woman using hand sanitizer

Hand santizer do: Rub your hands until they're dry

When using a hand sanitizer, don't just let your hands air dry. For the sanitizer to be most effective, rub your hands together until they're dry, Tuznik said.

Hand sanitizers should be at least 60% alcohol. The most commonly used safe version is ethanol, also known as ethyl alcohol.

Don't use a sanitizer with methanol. The U.S. Food and Drug Administration (FDA) warned that methanol is toxic and can be absorbed through the skin. It also warned that more than 100 sanitizers have been mislabeled as ethanol. You can find the list of hand sanitzers to avoid on the FDA's website.


man wearing pollution mask with filter

Masks with filter ports are dangerous

These type of masks are designed for people working around caustic fumes or chemicals, Tuznik said. They force out the air you’re breathing through the port. Instead of protecting someone from you, they propel your breath even farther and more forcefully.

N95s with the filter in the middle also do not prevent someone from spreading the virus. They filter air coming in but do let air out.


wearing gloves pushing grocery basket

Wearing gloves isn't necessary

There are no studies that show disposable gloves increase protection against COVID-19. The virus won’t infect you through your well-moisturized hands, and remember, surface contact is not a primary source of COVID-19 transmission. If you do infect yourself, it would be from touching your face – with or without gloves.


large floor fan

Floor fans aren't good

Large floor fans create a focused blast that pushes air and the virus a long way. A number of studies show you can get infected at a good distance because of those large fans, Tuznik said.

Besides gyms – most are closed right now – these fans are also common in outdoor restaurants and other venues where people gather.