COVID-19 questions answered: A Q&A with Dr. George Diaz, infectious disease expert

October 8, 2021 Christine Cox

Woman in full PPE in lab conducting research


Key takeaways:

  • Providence physician Dr. George Diaz treated the first COVID-19 patient in the US. 
  • Dr. Diaz discusses the benefits of and research behind clinical trials of COVID treatments.
  • People who are immunocompromised are at greater risk of a COVID breakthrough infection. 

COVID-19 continues to spread in many of our communities and as children go back to school, parents consider remote work versus in-office work and others weigh the risk of attending events, a lot of questions arise. That’s why Laurie Kelly, the Chief Philanthropy Officer and Senior Vice President at Providence sat down with infectious disease expert Dr. George Diaz to get answers to everyone’s COVID questions.  

Dr. Diaz is Section Chief, Infection Diseases and the Medical Director, Antimocrobial Stewardship and Infection Prevention at Providence Regional Medical Center in Everett, Washington. Perhaps the biggest reason Laurie spoke with Dr. Diaz is because he was one of the first doctors in the country to treat a COVID patient. Everett, Washington saw the very first patient with COVID-19 in the US and Dr. Diaz provided that first patient with a drug called remdesivir. Shortly thereafter, the Providence health system became very active in clinical research for COVID treatments. To date, Providence has been involved in several clinical trials for COVID treatments including:

  • Remdesivir
  • Tocilizumab
  • Monoclonal antibodies (Regeneron)

You can watch or listen to the full conversation between Laurie and Dr. Diaz, where he answers general questions about COVID along with audience questions, and you can also read highlights from their conversation below.

What is a clinical trial?

Dr. Diaz: Clinical trials help us figure out whether a treatment works. Generally, these are placebo-controlled studies, which means we're comparing a study medication to a placebo, to see if there's a difference in the outcomes between getting a study drug and getting a placebo. This is how we can prove that the treatment works. And then once we prove that, then all patients you know around the world can use these treatments for COVID, or any other clinical condition that's being studied.

Clinical trials are the way that we move forward in terms of the treatment of COVID. And thanks to the many volunteers across our country, we've made important discoveries in terms of reducing the chances of dying from COVID in the US. Clinical research is very important to help us move forward in learning about how to treat any disease, but it's been particularly helpful with COVID.

What is remdesivir?

Dr. Diaz: Remdesivir is an antiviral drug, which means that it blocks the ability of the COVID virus to replicate itself in a person. The National Institute of Health did studies that initially revealed that the people who took the drug, when they had COVID, had a shorter time to recovery and they also showed a possible improvement in mortality. At Providence, we followed-up on that work and discovered that remdesivir does appear to reduce the chance of dying from COVID by about 40% if started at the right time, which means when someone's in the hospital on oxygen. This clinical research from Providence was also published in a journal called Clinical Infectious Diseases.

What is the Delta variant?

Dr. Diaz: The Delta variant is a type of COVID-19 that has mutated or changed and is different from the original strain of COVID. The Delta variant also appears to be much more contagious. The original strain of COVID that we saw back in January of 2020 could infect, on average, two perhaps three people, for every person infected. With the Delta variant, it appears that it is much more contagious and one infected person can infect between six and nine people. So, it's radically more contagious than the original strain. In addition, it appears that it's a more virulent virus, meaning that it harms people more than the original virus.

You might say it's a double whammy: it is much more contagious, so more people can get infected, and it's more virulent, so more people end up in the hospital compared to the original strain.

How are people getting infected with COVID-19?

Dr. Diaz: The Delta variant of COVID is transmitted the same way that the original strain was. Transmission primarily happens when people breathe, cough or sneeze. And the virus tends to stay in the air longer where there's not good ventilation, which is primarily indoors. The major risk factor for transmission is someone who has a COVID-19 infection and who is generally indoors with another person. Now, if there are large crowds that are gathered outside and they're close together, it's certainly possible for outdoor transmission to occur as well. Wherever there are people in close proximity in an outdoor setting, that's another way COVID (and other things like colds and flu) can be transmitted. Transmission through your hands, such as touching things, is much less likely but certainly still possible.

Who is having breakthrough COVID cases?

Dr. Diaz: There are two components that we need to talk about when we discuss breakthrough cases. The first is people who are vaccinated and who then have a breakthrough infection and get sick enough to go to the hospital. Generally, that is a very small number of people. If you look at the patients who are in our hospitals, within Providence, right now, roughly 90 -- 95% of the people are unvaccinated.

Of the remaining small percentage of people who are vaccinated and who get a breakthrough infection, these are people who have immune systems that didn't respond very well to the vaccine to begin with. People who are immunocompromised from things such as organ transplant, chemotherapy and similar conditions where their immune systems aren't working may have a breakthrough infection. Those are the people that are primarily being admitted in the hospital with serious infections.

Patients who are immunocompromised in our community, which is not a small number of people, (people who are moderately or severely immune compromised are roughly 7% of our population in the US) are most vulnerable to getting breakthrough infections and getting really ill. The way we protect them is to prevent exposure and that means being vaccinated. Also doing the things that we know work such as masking and social distancing. These things will help protect those most vulnerable in our community from having a breakthrough infection.

What about pregnancy and COVID-19?

Dr. Diaz: Pregnant women are more likely to get a severe infection and become hospitalized if they get COVID-19. That is known. So, for that reason, all the national groups that treat pregnant woman recommend COVID-19 vaccine during pregnancy, as it appears to be entirely safe. Additionally, the immunity generated by the vaccine protects the infant as well. It’s very important for pregnant women at any stage of gestation to get vaccinated against COVID-19. There are so many COVID-19 infections in our country currently that the risk of infection is actually very high in pregnant women.

Dr. Diaz discusses these topics in greater detail, along with the topics below, all in the video above. Watch the video to learn more about:

  • The Delta variant
  • Current hospitalizations
  • Ivermectin
  • Odds of catching COVID multiple times
  • Children going back to school
  • How to talk to someone who is vaccine hesitant


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Related resources

Breaking down barriers to vaccine hesitancy

On the fence about getting your children vaccinated for COVID? Here are a few reasons to consider it 

COVID-19 boosters: Who's eligible, when? 

What to know about the Delta variant 

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