Could the Delta Variant of COVID-19 Ruin our Summer Plans?
Just as America was gearing up to celebrate the Fourth of July and the summer season, the Delta variant of COVID-19, discovered in India, threatened our holiday plans.
Could there be a repeat on this side of the pond of what happened in the United Kingdom? Britain was about to lift its final COVID-19 restrictions on June 21, which had been designated as “Freedom Day.”
Then, as Delta became the dominant virus strain, the Brits decided to delay lifting restrictions until July 19.
Robert L. Murphy, the John Philip Phair Professor of Infectious Diseases at Northwestern University Feinberg School of Medicine, where he serves as executive director of the Institute for Global Health, “The United Kingdom was about to end the lockdown, but delayed because of a surge in Delta. Are we at risk of that? Yes, we are. 95-99% of hospitalized patients in the United States right now are unvaccinated,”
He warned that the Delta variant is taking over in the United States, doubling every 10 days or so. “Pretty soon, almost all the viruses in the United States will be this Delta variant,” said Murphy, co-founder of Northwestern University's CoVAXCEN, a coalition of academic, government and industry experts on the COVID-19 pandemic. “I'm very worried.”
Egon Ozer, MD, PhD, assistant professor of medicine in the Division of Infectious Diseases and director of the new Northwestern University Center for Pathogen Genomics and Molecular Evolution (CPGME) contained in its Institute for Global Health, said there are good reasons for concern about the Delta variant.
“Delta seems to be more transmissible than previous variants. We think of the Alpha variant as being 50% more transmissible than other variants before it. Now, the Delta variant seems to be about 50% more transmissible than the Alpha variant,” he said. “It’s an incremental increase in the ability of the virus to transmit and cause infections.
“The Delta variant is starting to increase in numbers. And it seems likely that it will become the dominant strain, especially amongst those who are unvaccinated or not fully vaccinated. It remains to be seen, but it seems like it’s probably going to be the case.”
But, Ozer said, there is good news because testing has shown that the Pfizer BioNTech and Moderna mRNA vaccines “seem to be highly effective in protecting against the Delta variant. They are about on the same level as they are for previous variants, though incrementally smaller, but the difference is probably clinically not so relevant.”
He said people are still susceptible to the Delta variant after the first shot, which confers only 30% protection. “Protection doesn’t go up into the high 80s until two weeks after the second dose,” the researcher said,
Murphy said Delta “is going to spread like wildfire among the people who are unvaccinated. Usual mitigations may not work as well. It may cause slightly worse disease but that's not certain. Essentially, everyone not vaccinated will get this.”
The unvaccinated are concentrated in certain states, especially in the Southeast and the Midwest, where vaccine hesitancy remains high. Alabama, Louisiana, Mississippi, Tennessee and Wyoming are among the states that have been slowest to vaccinate.
Also, children under 12 are unvaccinated. Murphy said, “Fortunately, kids, so far as we know, if they practice some type of mitigation in the daycare center, even if they do get infected, typically have very mild disease. So, it’s not as critical an issue. Soon though, probably by the end of the year, there will be vaccines even for kids that young that go to daycare, so that will resolve that problem.”
Northwestern COVID-19 Vaccine Communication and Evaluation Network (CoVAXCEN) seeks to achieve consensus on a variety of issues related to the safety and efficacy of COVID-19 vaccines and then produce and disseminate written materials for scientists, healthcare professionals, and the general public describing its conclusions.
Headquartered in the Institute for Global Health's Center for Global Communicable and Emerging Infectious Diseases with the cooperation of the Center for Communication and Health, we seek to achieve consensus on a variety of issues related to the safety and efficacy of COVID-19 vaccines and then produce and disseminate written materials for scientists, healthcare professionals, and the general public describing its conclusions.
Howard Wolinsky is a Chicago-based freelance medical writer and author. He is the former medical reporter for the Chicago Sun-Times. He has won awards for medical writing from the American Public Health Association, the American Bar Association, and the Association of Health Care Journalists, the Chicago Headline Club’s Peter Lisagor Award (“the Chicago Pulitzer''). The Sun-Times twice nominated him for the Pulitzer Prize.