Last in your body stay with us. Is this science Friday from W. N. Y C studios? I'm Dr Ball Club and I'm the president, CEO and executive dean of the Baylor College of Medicine. The Texas Medical Center is really unique. We agreed early on to start meeting daily. Every single CEO in the medical center was on the calls every day at seven A.m.. His biggest health crisis in 100 years, and it's right here in our city, and what can we do collectively to try and make the right decisions? When you have diverse perspectives and different expertise, you often make better decisions. But there is an issue. We all had a slightly different opinion. But what was remarkable almost all the time we came down with complete consensus, and we're still meeting. You know, talking about who's got this amount of vaccine has got that amount of accent who could do what we have managed better than most large urban centers better than Chicago, L, a New York and it's because we work together. Tested. Houston's response to covert 19 is produced in partnership with ST Lukes Health Visit Houston public media dot org's slash tested for more This is science Friday. I'm Ira Plato. Since the start of the covert 19 pandemic, we've equated hope in getting out of this mess with the concept of herd immunity. Some people call it community immunity. That's when a certain percentage of the population is immune to a disease, mostly through vaccination with covert experts have said. We need somewhere around 70 to 90% of the population to be immunized. To meet this goal. Now that all adults in the U. S are eligible for the vaccine, where we act and has that 70 to 90 number changed, some experts now say with variants and vaccine hesitancy, Herd immunity may not be possible here in the U. S. Well here with me to break down. This and other recent Covic quandaries is my guest. Dr Angela Rasmussen. Research Scientists at Vito Inter Vac, the University of Saskatchewan's Vaccine Research Institute in Saskatoon, says Catch one Canada Welcome to Science Friday. Thanks so much for having me back. Kyra, welcome back. Angela, Where do you fall on the herd Immunity, optimism scale, the also think that it's unattainable. So I think that that some of that depends on what the herd immunity threshold actually is, and some of that also depends on other factors, such as how much transmission is actually occurring. In the community. Now, one thing I think that people have been confused about with regard to the herd Immunity threshold, which is that number that you just referred to at which a virus would not be able to spread within a population because too many people are immune. That's an estimate based on transmission dynamics based on susceptibility in the population, And for that reason, it's very difficult. T nail down a specific number. But I think some of the confusion has been that people think we absolutely have to get to that number. And then once we get there, things will magically change in the pandemic will be over. But unfortunately, it's really not that simple. We can look at a country like Israel, for example, that has now vaccinated about 60% of the adult population, and we can see that they've had long sustained reductions in transmission in the overall community. Now, 60% is nowhere near the herd immunity threshold. And there probably is some population immunity from people who were naturally infected with covert adding to that, But I think that a n'importe point that we should all think about is that we might not have to hit. The herd Immunity threshold, which currently is calculated it somewhere above 80% of people immunized to see sustained reductions in transmission. Like what Israel is seen. Now, at the beginning of their vaccination campaign, they had a pretty restrictive lockdown. On DATs, not the only way to do it. But if you get transmission down enough while boosting vaccination enough in the population you can actually get to a place that is functionally like the herd immunity threshold. Before you actually get there just because there's not very much virus in the community and you have a growing number of people who are immunized, so it's a really tough concept. I think it would be a lot easier for people if we could just say, Hey, we're aiming for 80 85% 90% vaccinated and Of course, it's great to vaccinate as many people as we possibly can. But that's not necessarily the metric that we have to hit in order to start relaxing some of the restrictions and being able to return to Quote unquote normal. But Herd immunity is really not a national concept. Herd immunity is really regional. And as you pointed out, some people call it community immunity for this reason. If you have overall 70% of people vaccinated, there's still maybe communities where there's a very low vaccination rate that's far under that in which you will have a lot of susceptible people. Interesting point. I know that right now, More than half of the U. S. Adults have gotten at least one dose of a vaccine. But some states have only been open toe all adults for less than a month. Is it too early to really tell how many people will get vaccinated and how much to open? What's your view on that? So if you look at New York, for example, which has plans to fully reopened by May 19th I do think that that is premature again because of this herd immunity being a regional issue and in some places in New York state, you're going to have people with very high levels of immunity, who have been able to access vaccines more readily and who were very enthusiastic about getting it..