Public Health

Mira Irons, MD, looks behind last week’s growth of cases in national hot spots


Watch the AMA's daily COVID-19 update, with insights from AMA leaders and experts about the pandemic.



In today’s COVID-19 update, Todd Unger, AMA Chief experience officer and Mira Irons, MD, AMA chief health and science officer, take a weekly look at the numbers, trends and latest news about COVID-19, including new records set in the United States for the number of people infected.

Learn more at the AMA COVID-19 resource center.


  • Mira Irons, MD, chief health and science officer, AMA

AMA COVID-19 Daily Video Update

AMA’s video collection features experts and physician leaders discussing the latest on the pandemic.

Unger: Hello, this is the American Medical Association's COVID-19 update. Today we're taking our weekly look at the numbers, trends and latest news about COVID-19 with AMA's Chief Health and Science Officer Dr. Mira Irons in Chicago. I'm Todd Unger, AMA's chief experience officer in Chicago. Dr. Irons, let's start by reviewing this week's numbers. What's happening across the country with new cases and deaths?

Dr. Irons: So, Todd, we're continuing to break records in the United States, sadly. The current numbers are 4,234,140 individuals have been diagnosed with COVID and we're looking at 146,935 deaths so far. Last week, we continued to set records, more than 70,000 in a single day. On Friday, we exceeded 74,000 in a single day, and we passed the 4 million mark last week. However, over the weekend, things seem to have slowed. Today's number for new cases is at 55,900. So that's less than last week. And the deaths that have been reported are 475, which is half of the seven-day rolling average. I always am a little careful about Monday statistics because you don't know whether it's a reporting issue and we're going to start to catch up into the rest of the week. But there are several states, the large surge states that also look like they're plateauing in terms of positivity rate on testing. So maybe, maybe those are early signs that seem to indicate that there may be some plateau in the large states.

Unger: Let's hope those trends hold. What states are we still seeing though, most significant hotspots?

Dr. Irons: Pretty much last week, Florida, Texas, Arizona, California. Florida surpassed New York in reported infections, so it's now number two. California, still in that number one spot, but we're also starting to see little spots, small spots in the rest of the country, Louisiana, which you'll remember we heard a lot about early on in the spring is showing some upticks. Several, Indiana, in a certain spots came up and then seemed to have come down. Wisconsin is coming up. The small upticks are areas where contact tracing and isolation we may be able to get ahead of the small uptake so that they don't become surges.

Unger: We're seeing a number of the kind of small surges being driven by people getting back together again. What are you seeing about that?

Dr. Irons: Well, absolutely. I mean, over the weekend, you can't turn the news on today without seeing the beaches. Miami Beach was packed. The beaches were packed around the country and the new super spreader events seem to be house parties. You know, just people that are trying, that are expanding their bubble and are getting 20, 30 people together for a barbecue. A lot of reports about house parties leading to 10 infected, 20 infected, 30 infected. It just means that that people have to continue to be careful.

Unger: Well, we've seen a lot of vaccine coverage in the news lately. Can you talk about where we stand with vaccine trials and timing and see any promising developments in the horizon?

Dr. Irons: Oh, absolutely. And today's actually a good day to have that discussion. So the Moderna vaccine that's been made and developed in coordination with the National Institute of Allergy and Infectious Disease started their phase three trials in the United States today, started enrolling in phase three. Just to back up a little, the phase one and two trials are actually geared toward assessing safety and dosage. So there are small numbers of people that get the vaccine in different doses. And the intent of that is just to make sure that you have information on safety.

Phase three trials are the ones we really need, because those are the trials that are expanded to larger numbers of people. They are placebo-controlled, and they really will tell you more about safety, but also efficacy. You need a vaccine that's safe, but you also have to make sure that it's efficacious. So it's the phase three trials for the Moderna vaccine that is starting today. The goal of that trial is to enroll 30,000 people, 15,000 would get the vaccine, 15,000 would get a placebo. It's meant to have two doses and the real focus is to get different populations of people. So people that are vulnerable, different race and ethnic groups, different ages, because you want to make sure that once you have efficacy data that it is effective in all of the different populations that might receive it.

Unger: About how long does a phase three trial expected to last?

Dr. Irons: So it depends. It depends on enrollment. You got to get 30,000 people enrolled, but it also, the efficacy part of it will depend on the activity of disease, the activity of the virus in the community that the people that are living in. And so if you look at another vaccine that we've heard a lot about the Jenner Oxford Institute vaccine from England, that's being done in collaboration with AstraZeneca, that vaccine has already started phase three trials in Brazil. And in South Africa where the activity of COVID is sadly high, and will be entering the United States phase three vaccine trials in, I think sometimes later this summer. So the goal in the US is, there's a coordinated and harmonized clinical trial network that will test each of those vaccines in the operation warp speed and the Pfizer vaccine sequentially.

Unger: Even if a phase three trials were to go well, that would put us well into the fall. Are we expecting any kind of progress by the end of this year?

Dr. Irons: Hard to tell. Hard to tell, but I think people are being really cautious. But in listening to people who are making, who are really commenting on this from the science part, the hope is that at least one of those vaccines may show efficacy by the end of this calendar year into the fall. As you all know, manufacturing is actually being done. All of the vaccines that are scheduled to go into phase three of three trials are already being manufactured so that we don't see that usual gaps that we see between deciding that something has efficacy and then having to manufacture millions and millions and millions of doses. So hopefully by the end of the year and the beginning of the 2021, for sure.

Unger: Okay, well, let's turn our attention to some of the revisions that we saw in terms of guidance from the CDC in the last week. Some of those have prompted questions from health officials. Can you talk about some of those?

Dr. Irons: Sure, Todd. So about a week ago Friday, the CDC issued new guidance on return to work for health care professionals and also for hospitalized patients. Prior to this guidance, prior to the revision, there were two strategies to help inform return to work. One of those was a test-based strategy where you would test someone again to make sure they were negative. And the other was a symptom-based strategy that didn't require that second, that negative test at the end. So the updated guidance is really focused on a symptom-based strategy. It eliminated the test-based strategy as a way to return people back to work. And that's really because the more people we test, we are beginning to appreciate the fact that some people who have actually recovered from the disease and no longer have replication-competent virus in order to infect someone still may have a positive test because of remnants of RNA that are still in their system perhaps for months. So you would be holding back individuals from reentering the workforce or discharging patients from the hospital who no longer have the ability to transmit the virus to others.

The decision to change that, to update that guideline was made based on evidence. And the CDC site actually has a decision memo on their site that goes through all of the evidence that was reviewed, that helped inform that decision.

Unger: All right, well, one of the other big areas of revision was around school guidelines and school reopenings. Can you talk about the new guidance there for schools?

Dr. Irons: So if you're referring to the CDC guidance, it was really an update and further clarification of guidance they had already provided. I think everybody's goal is to ultimately get children back into the school system, but everyone also agrees that it has to be done in a safe environment. And so while the updated guidance actually emphasized that the goal was to get kids back into school, it also emphasized the need for safety, the need for cleaning, the need for social distancing, the need for perhaps hybrid models. I think there are concerns. There are certainly concerns, especially in areas where high activity of COVID is.

Unger: So a lot of counsel for really taking into account local decision making. Is that right?

Dr. Irons: Absolutely. Absolutely. And I think we're starting to see cities and municipal areas starting to pull back and reconsider the fall. Many we're thinking of introducing hybrid models anyway, with some combination of in-person participation and virtual participation, but I think that the guidance is that people really need to work with their local communities in determining what to do.

Unger: Well, speaking of a more localized decision, we see a lot of states and cities now putting restrictions in place on travelers from other states. What are you seeing in that realm?

Dr. Irons: Absolutely. Well, I think the first states that came out with that a few weeks ago were New York, Connecticut and New Jersey. Chicago is the city followed very closely. And I think that people, local officials, local and state officials are trying to decrease spread into their communities from people from coming from hotspots so many cities and states now have 14 day quarantines.

Unger: One other interesting development, especially when there is still some remaining issues around face coverings. We've seen the private sector stepping into that equation. What are you seeing there?

Dr. Irons: Well, I think we all heard last week that many of the large businesses, Walmart and some of the other large stores, have instituted required mask policies. The latest to come in is McDonald's and I think that the more businesses that step up and really confirm the importance wearing masks, I think will help get the message to the public that masks really have to be worn, to cover their nose in their mouth, not held on their hands and in areas especially where social distancing is not possible.

Unger: Well, one final question, and it's closely related to the issue about school reopenings is around children and their ability to transmit the virus. What are the latest findings in that realm?

Dr. Irons: So we've always, we have seen from the very beginning of the COVID pandemic, that children seem to be less effected by COVID-19. And also, there was early data that showed that transmission from children was less than that from adults. So there is recent data from South Korea that looks at the fact that it seems as though children that are less than 10 transmit less than adults do, but perhaps children who are 10 and above transmit at levels that are pretty equal to adults. Now, I have heard Dr. Birx on TV last week at one of the news conferences say that she's interested in US data on that, so I think we're going to be following that data closely.

Unger: Well, thank you very much, Dr. Irons, the key takeaway remains to wear a mask, wash your hands and maintain physical distancing. That's it for today's COVID-19 update. Appreciate you being here and sharing those trends with us. We'll look forward to talking with you again next week. Hope we will continue to see some progress. We'll be back tomorrow with another COVID-19 update. For updated resources on COVID-19 visit Thanks for joining us and please take care.

Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.