Delta variant likely here; Expert says worse strains could emerge

With the Delta coronavirus variant dominant in nearly every U.S. state, veteran epidemiologist Joseph McCormick, founder of the UTHealth School of Public Health in Brownsville, said there’s little doubt the strain is already in the Rio Grande Valley, though it’s not clear to what extent since it takes specific biological tools to measure.

“We unfortunately are not able to do sequencing in our (UTHealth) laboratory,” he said. “We are looking for variants. We were able through our standard PCR test to identify the B.1.1.7 variant that originated in the UK, but so far that has not worked for the Delta variant. That doesn’t mean the Delta variant is not here, it just means that our technique won’t pick it up.”

The new strain, which originated in India, where the coronavirus death toll has surpassed 400,000, has been detected in Brownsville in clusters of people who were fully vaccinated but caught Delta anyway, McCormick said. The variant was discovered in several individuals during unrelated, routine testing and the people in question were not exhibiting symptoms, he said.

The latest data shows Delta to be 40% to 50% more contagious than B.1.1.7, also called “Alpha.” It’s also more dangerous, McCormick said.

“We do know that,” he said. “That’s why we’re seeing young people being hospitalized.”

The old argument that COVID-19 is a mild disease and young people don’t need to worry about getting vaccinated is doubly wrong when it comes to Delta, McCormick said.

“The Delta virus is more infectious,” he said. “It’s more virulent. That means that it spreads more easily and makes people sicker, even at a young age.”

In Missouri, which has one of the nation’s lowest vaccination rates, Delta is sweeping the state and putting large numbers of residents 40 and under in the hospital, some of them on ventilators, McCormick said. Cameron County has a much higher vaccination rate than the national and state average, not to mention Missouri, though a similar trend is reflected in the county’s recent COVID-19 report, he said.

Of 54 new cases of the virus among the county’s general population according to the July 9 report, only six were above the age of 50, McCormick noted.

“That’s a reversal of what we’ve seen,” he said. “Our hospitals have also seen a shift in the age of their hospitalizations.”

McCormick praised county and city of Brownsville officials for their success in getting residents vaccinated but said it’s time for holdouts to get vaccinated now. Not having enough people vaccinated is what allows the virus to continue to replicate and mutate into highly contagious variants like Delta, he said.

With hundreds of millions of people around the world already vaccinated against COVID-19 virtually without incident, the safety and effectiveness of current vaccines is beyond question, McCormick said.

“When the population is vaccinated you dramatically reduce the replication and the likelihood therefore of getting these variants,” he said. “It takes a hell of a lot of replications to create these variants. Most mutations are lethal to the virus. I mean, 99.999 percent of the mutations are lethal to the virus.”

Still, it only takes one or two mutations that don’t kill the virus to allow it to wreak havoc, McCormick said.

“That tells you that this is a statistical issue,” he said. “The more replication, the more the likelihood that we’re eventually going to have an escaped variant. Right now we don’t have that. That’s why the push for getting vaccinations is so important.”

Friends and family members need to push each other to get vaccinated because it’s too important not to, McCormick said, stressing that it impacts the entire community, not just the individual.

As for the odds that vaccine booster shots will be needed at some point, McCormick said it depends on whether large numbers of people continue to refuse to get vaccinated, but that in any case it’s not necessary now, he said. Meanwhile, a company called Novavax is developing a different type of vaccine that early trials indicate is more effective than the Pfizer, Moderna and Johnson & Johnson vaccines currently available, though it’s too soon to know definitively, he said.

“That could be a source for a booster as well,” McCormick said. “We don’t necessarily have to get boosted with the same vaccine we got originally. So there may be some new vaccines, either made by Pfizer or Moderna or any of the other companies, as well as this one, that will address the issue of these variants. We just have to wait and see.

“But it’s not necessary now, because the vaccines are effective against even the Delta variant. We don’t need a booster now but you may want it down the line.”

sclark@brownsvilleherald.com