On Thursday, three leading public health experts hosted a Zoom call to discuss the current state of the COVID-19 pandemic in Texas. As the understanding of the virus within the scientific community has grown, the advice of experts—and the models they’re using to forecast the future of the disease’s impact—has evolved too. The conversation was hosted by the nonprofit scientific institution The Academy of Medicine, Engineering & Science of Texas (TAMEST), and featured Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine; Rebecca Fischer, assistant professor of epidemiology and biostatistics at Texas A&M; and Lauren Ancel Meyers, professor of integrative biology at the University of Texas at Austin. The three scientists shared their views on the state of the pandemic, and discussed the risks of Texas’s reopening.
Here are the key takeaways from what they had to say.
Texas has fared relatively well so far, but a new wave of infections is a real possibility
Unlike other regions, Texas seems to have instituted social distancing and lockdown measures before the disease began wide-scale community spread. In New York, Hotez said, community transmission likely began in early February, and continued spreading until the city instituted social distancing measures on March 22. In Texas, though, our public safety measures went into effect before significant spread. Hotez says that relatively early action likely slowed the outbreak of the disease greatly.
“That few weeks of extra time made a huge difference,” Hotez said. But it also raises a question: how do we ensure that we continue to reap the benefits we saw from the sacrifice of social distancing, even as the state begins reopening businesses and relaxing guidelines? Hotez, whose son works in the beleaguered oil and gas industry, argued that economic recovery and the slowing of the disease are strongly correlated, rather than at odds with each other. “How do we build the public health infrastructure that we need to sustain that recovery?” he said. “My big worry is that things will move ahead for the next couple of weeks, but as we move into the summer and fall, our ICUs will fill up. That’ll have people very worried about returning to work, and we’ll begin to lose ground.”
Meyers, whose team at UT-Austin has created a forecasting model used by the New York Times and 538.com as part of their projections on the disease, cautioned that a second wave may be an inevitability, based on our current understanding of how the disease spreads. According to Meyers, the R0 figure, which indicates how many other people a COVID-positive individual is likely to infect, dropped to 0.8 in Austin during the height of social distancing—but as of mid-May, it had climbed to around R0 0.95. As long as that number is under 1, the disease will eventually stop spreading, and the lower the R0 value, the quicker the outbreak comes to an end. But absent a lockdown, that number will continue to grow.
A second lockdown may be necessary
Restaurants, retailers, and hair salons have reopened, while bars and other businesses may get the green light from Governor Greg Abbott on May 18. But according to Meyers, there are two likely scenarios for the future, based on what we understand right now of the spread of the disease. Both share one thing in common: a likely spike in hospitalizations in June. Where they diverge is in how authorities and the public in general respond.
In one scenario, there are no formal restrictions on which businesses are allowed to open, no enforcement of social distancing policies, and no additional action taken when a second wave begins. (The modelers assume that about half the population is still hesitant to resume normal activity regardless of formal rules.) In that situation, she said, “hospitalizations would peak to unmanageable levels, even with a very optimistic estimate of their surge capacity, by mid-June.” If that happens, the sort of death toll that places like New York and Italy experienced would come to Texas. “That does not include excess deaths that weren’t from COVID,” she said, estimating that the death toll would quickly reach into the thousands.
In the second scenario, restrictions are again fully lifted, but once hospitalizations begin to spike, officials take swift action. In that situation, “We put our foot on the brake before that happens,” said Meyers. She mentioned eighty new hospitalizations in a day in Austin as one possible trigger for a local lockdown, which could be lifted when new admissions fall below a certain level. “Our projection under that policy is that in mid-June, we’d see a new lockdown lasting three months,” she said. That’s significantly longer than the one we experienced from mid-March to May 1. In this case, there’d likely be a third wave later in the fall—but at that point, enough of the population would probably have been exposed, and presumably have at least short-term immunity, that an additional lockdown wouldn’t be necessary.
“We need to have really good situational awareness,” she said. “We are hard at work estimating how quickly the virus is spreading as policies change, so we can take steps to slow transmission before it’s too late. If you wait until things look threatening in your hospitals, it’s too late.”
Our current testing capacity is inadequate
The University of Texas model, which focuses on Austin but which Meyers said largely applies to other cities around the state, isn’t based on testing data that comes from the state. Rather, Meyers said, it’s based on “unprecedented coordination” with the city, local hospitals, and researchers to get an accurate count of hospital admissions every day.
Hotez asked the other scientists about the problems that stem from the state’s relatively modest amount of testing. “How do you have a robust alert system without testing data to feed into it?” he asked. Fischer said the paucity of testing means that researchers still don’t have a clear idea of how widely the virus is spreading, or what’s happening among groups who face barriers to seeking care or who are asymptomatic.
“If there is a way to expand testing to make it accessible to everyone, that’s our most valuable tool,” Fischer said. “Fever screening is not our most useful tool—it’s too labor-intensive, without much benefit. So when we talk about, say, students coming back to live in dorms, how do we do that? I don’t know the answer to that question.”
There probably aren’t a huge number of Texans with antibodies
One consequence of our current lack of testing capacity is that we don’t know how many Texans have been infected—which means that we don’t know how far along we are on the path toward herd immunity, where the disease stops spreading because most people are immune to it. Currently, the detected cases represent just .2 percent of the population in Texas—and that’s likely an undercount. Even if the actual number of infections is ten times the number of diagnosed cases, that’s still not enough to bring us close to herd immunity, Fischer argued. “Without a way to expand and liberally test people, including those without signs, it’s really hard to gauge this,” she said. And scientists aren’t even certain that an infection confers some period of immunity.
“We don’t actually know if people are immunized after infection,” Meyers said. “But unfortunately, the models are consistent with influenza and other respiratory infections—that this spreads quickly and silently, so over 50 percent of the population will have to be infected before this thing starts to dissipate on its own. It’s very likely that very few people have been infected so far, so there’s no silver bullet until we get a vaccine.”
One grim possibility Meyers noted is that in the event we do see our hospitals overwhelmed from an unchecked spread of the disease, those who survive could get to that point more quickly. “If this gets out of hand and a single-wave pandemic runs its course, we might be on the other side of this in a very bad way in a short amount of time,” she said—at the cost of many thousands of lives.
Nursing homes have seen the highest mortality rates
The impact of the disease in Texas has thus far fallen largely on the elderly, especially those who live in long-term care facilities. While the overall case fatality rate is around 3.8 percent—that is, 3.8 percent of people who receive a clinical diagnosis die in a hospital from COVID-19—a staggering 43 percent of those deaths have occurred among nursing-home residents. Parts of the state that have seen clusters of COVID-19 in nursing homes have seen much higher fatality rates. In the seven-county Brazos Valley region, for instance, it’s at nearly 11 percent.
“People 65 and older may really need to be sheltering in place for the foreseeable future, even if the rest of the population relaxes,” Meyers said.
Texas can beat this—if we tap our best and brightest to solve it
The conversation wasn’t particularly optimistic, in terms of short-term hope that transmission of the disease (and subsequent hospitalizations and deaths) will stop without additional lockdown measures. But one piece of hope that did come up centered on the ability and ingenuity of Texans to build a safer, smarter way of doing things, and an economy that adapts to the reality of the situation.
Hotez spoke of harnessing the robust “scientific and engineering horsepower” of Texans to create systems that can manage the spread of the pandemic. Given the amount of skill and talent in Texas, it might be possible to put in place syndromic surveillance and contact-tracing measures faster than hospitalizations and deaths spread. Because those are lagging indicators, which means that the disease spreads for several weeks before the impact of those things is felt around the state, there is still time to put them in place—if we start before those things happen.
“The short answer is we need to bring the great minds and engineers together to tackle this challenge,” Meyers said.
But even if you’re not about to develop a contact-tracing app or a system for investigators to track and notify everyone an infected person comes in contact with, she thinks there are ways we can all help slow the spread of the disease—one that would involve individuals taking on the responsibility of staying at home, and notifying the people they’ve come in contact with, as soon as they start experiencing symptoms, so those people can also avoid potentially infecting others. “It could actually go a long way,” she said, “Given how under-equipped we are for testing, contact tracing, and isolation.”