Dallas County may achieve collective immunity in the summer – but that doesn’t mean things will be back to normal

With the increase in vaccinations and the reduction of new cases of COVID-19 in many parts of the country, it may seem that the end of the pandemic is near. Many experts predicted that the country will begin to move towards normality sometime between late spring and autumn.

But how is normality? How will we know when we get there?

And how will Governor Greg Abbott’s decision to end statewide coronavirus restrictions affect the schedule?

Before the country can return to normal, a sufficient number of the population must develop resistance to the coronavirus to prevent its spread.

Experts have established this limit, known as herd immunity, in about 80% of the population. Recently, experts at the Parkland Center for Clinical Innovation, or PCCI, projected that Dallas County could achieve collective immunity as early as late June.

Abbott’s decision to lift restrictions on coronavirus – ending a mask mandate and opening companies to full capacity – does not change that projection, the PCCI scientists said. But the move could shift the burden of the disease to essential workers who have not yet been vaccinated, warned other experts.

Many people equate collective immunity with normality, but the two are not the same, said Dr. Holt Oliver of PCCI.

With collective immunity, “the risk of infection will be much less,” he said. “But that doesn’t mean that everyone should just take off their mask when we get to that place.”

When Dallas County achieves collective immunity, the virus will still be circulating, but the risk of major outbreaks that overwhelm hospitals will be greatly reduced.

Normality will resume only when the number of new confirmed and probable cases drops below 1 per 100,000, or 27 new cases per day for 14 consecutive days, according to Dallas County COVID-19 response metrics. The county’s current infection rate is 21 new daily cases per 100,000, or 697 new daily cases total, placing it in the second highest “orange” category of community transmission, according to a School of Health database Brown University Public School.

By the definition of the county, even normality is not the same as life before the pandemic. Its public orientation towards the “new normal” foresees the continuous use of the mask, social distance and the washing of the hands when eating in restaurants, shopping in stores and attending large meetings.

Experts also point out that collective immunity is not a permanent state. “It’s a fluid state,” said Dr. Michael Mina, an epidemiologist at the Harvard School of Public Health TH Chan. “He comes and then he can go.” Mina said that immunity among those infected at the start of the pandemic or vaccinated in early 2021 could decrease in the fall, potentially generating new waves of cases.

Variants of the coronavirus can also impair the herd’s immunity. The Centers for Disease Control and Prevention identified three main variants of concern. One is a highly infectious strain first identified in the UK. Two other strains, one identified for the first time in South Africa and one detected for the first time in Brazil, spread more quickly and can also infect some people who have been vaccinated or recovered from previous cases of COVID-19.

Last week, Houston became the first city to report the discovery of all three worrying variants among its patient samples.

“It seems likely that we will need to continually update vaccines,” said Spencer Fox, a pandemic expert at the University of Texas at Austin. “I’m not sure how often, but it can be something like seasonal flu.”

Dr. John Carlo, a former medical director at Dallas County Health and Human Services, said the new coronavirus could behave more like measles. The measles virus circulates at very low levels and returns in the pockets when vaccination rates or herd immunity decrease.

PCCI experts recognize that the herd’s immunity can weaken and return. Their prediction depends on vaccination rates of at least 65,000 new injections per week and lasting immunity.

As of March 1, 45.5% of Dallas County residents had immunity to the virus, the PCCI estimates. Between now and the end of June, the PCCI expects 130,000 adults and children (5% of the population) to be infected with COVID-19 and approximately 1 million, or 40% of the population, to be vaccinated.

Steve Miff, chairman and CEO of the PCCI, said he did not think Abbott’s decision to end Texas coronavirus restrictions would significantly affect the center’s projections.

“At the very least, we can reach herd immunity levels more quickly, but getting there through more people being infected is not safe for anyone,” he said. “We can and must obtain collective immunity through vaccines.”

Dr. Philip Huang, director of Human Services and Health for Dallas County, said in an interview that cases may increase in a similar way to what occurred after Memorial Day weekend, after Abbott lifted the initial blockade of the state.

“There are still many people who remain unvaccinated and unprotected,” he said.

Along with its forecast, the PCCI released a map showing the estimated percentage of people in each zip code in northern Texas with immunity to coronavirus. Rates range from 5.6% at CEP 75067 north of Coppell to 69.6% at CEP 75202 in downtown Dallas. Miff said that the PCCI does not have a view on what explains the disparate rates.

Huang said the postal code map would be useful in identifying priority areas for vaccination efforts.

Carlo added that frontline workers and those with less access to vaccines would bear the brunt of any new outbreaks.

“It is completely unfair to those who are part of the essential workforce who have not yet been able to receive vaccines and are now more likely to be exposed by people who enter supermarkets, restaurants and bars without their masks on,” he said. “It is really unfortunate that we couldn’t wait any longer for us to be able to vaccinate these people.”