With vaccinations scaling up and new cases of COVID-19 decreasing in many parts of the country, it may seem as though the end of the pandemic is in sight. Many experts have predicted the country will start moving toward normalcy sometime between late spring and fall.
But what does normalcy look like? How will we know when we get there?
And how will Gov. Greg Abbott’s decision to end coronavirus restrictions affect the timeline?
Before the country can return to normal, enough of the population needs to develop resistance to the coronavirus to stop its spread.
Experts have put that threshold, known as herd immunity, at about 80 percent of the population. Recently, experts at the Parkland Center for Clinical Innovation, or PCCI, projected that Dallas County could reach herd immunity as early as late June.
Abbott’s decision to lift coronavirus restrictions — ending a mask mandate and opening businesses to full capacity — doesn’t change that projection, said scientists at PCCI. But the move could shift the disease burden to essential workers who have not yet been vaccinated, other experts have warned.
Many people equate herd immunity with normalcy, but the two are not the same, said PCCI’s Dr. Holt Oliver.
With herd immunity, “your risk of having infection will be much lower,” he said. “But that won’t mean that everyone should just take off their mask when we get to that place.”
When Dallas County reaches herd immunity, the virus will still be circulating but the risk of major surges that overwhelm hospitals will be greatly reduced.
Normalcy will resume only when the number of confirmed and probable new cases falls below 1 per 100,000, or 27 new cases per day over 14 consecutive days, according to Dallas County’s COVID-19 response metrics. The county’s current rate of infection is 21 new daily cases per 100,000, or 697 total daily new cases, which places it in the second-highest “orange” category of community transmission, according to a database from Brown University’s School of Public Health.
By the county’s definition, even normalcy is not the same as life before the pandemic. Its public guidance for the “new normal” calls for continued mask-wearing, social distancing and hand washing when eating at restaurants, shopping in stores and attending large gatherings.
Experts also point out that herd immunity is not a permanent state. “It’s a fluid state,” said Dr. Michael Mina, an epidemiologist at the Harvard T. H. Chan School of Public Health. “It comes and then it can go.” Mina said immunity among those infected early in the pandemic or vaccinated at the beginning of 2021 could wane by fall, potentially prompting new waves of cases.
Coronavirus variants could also erode herd immunity. The Centers for Disease Control and Prevention has identified three major variants of concern. One is a highly infectious strain first identified in the United Kingdom. Two other strains, one first identified in South Africa and one first detected in Brazil, spread faster and can also infect some people who have been vaccinated or have recovered from previous cases of COVID-19.
Last week, Houston became the first city to report finding all three variants of concern among its patient samples.
“It seems likely that we will need to continually update the vaccines,” said Spencer Fox, an expert on pandemics at the University of Texas at Austin. “I’m not sure of the frequency, but it might look something like seasonal flu.”
Dr. John Carlo, former medical director of Dallas County Health and Human Services, said the novel coronavirus could behave more like measles. The measles virus circulates at very low levels and returns in pockets when vaccination rates or herd immunity wane.
Experts at PCCI acknowledge that herd immunity could fade and return. Their forecast depends on vaccination rates of at least 65,000 new shots per week and lasting immunity.
As of March 1, 45.5% of Dallas County residents had immunity to the virus, PCCI estimates. Between now and late June, PCCI expects that 130,000 adults and children (5% of the population) will be newly infected with COVID-19 and approximately 1 million, or 40% of the population, will be vaccinated.
Steve Miff, PCCI’s president and CEO, said he didn’t think Abbott’s decision to end Texas’ coronavirus restrictions would significantly affect the center’s projections.
“If anything, we might get to herd immunity levels faster, but getting there through more people being infected is not safe for anyone,” he said. “We can and should get to herd immunity through vaccinations.”
Dr. Philip Huang, Dallas County Health and Human Services director, said in an interview that cases may surge back similar to the way they did after Memorial Day weekend, after Abbott lifted the state’s initial lockdown.
“There’s still a lot of people who remain unvaccinated and unprotected,” he said.
Along with its forecast, PCCI put out a map showing the estimated percentage of people in each North Texas ZIP code with immunity to the coronavirus. Rates range from 5.6% in the 75067 ZIP code north of Coppell to 69.6% in downtown Dallas’ 75202 ZIP code. Miff said PCCI did not have insight into what accounts for the disparate rates.
Huang said the ZIP code map would be helpful with identifying priority areas for vaccination efforts.
Carlo added that frontline workers and those with the least access to vaccines would bear the burden of any new surges.
“It’s completely unfair to those that are in the essential workforce that have not yet been able to get the vaccines and now are more likely to be exposed from people coming into grocery stores and restaurants and bars without their masks,” he said. “It’s just really unfortunate that we couldn’t wait just a little bit longer so that we could get these folks vaccinated.”
