Fauci: Failure To Control Delta Variant Could Lead To ‘Worse’ Mutations That Evade Vaccines

Published 2 years ago
Dr. Fauci Testifies To Senate Health Committee On Country’s COVID-19 Response
(Photo by J. Scott Applewhite-Pool/Getty Images)

TOPLINE: Top infectious disease official Dr. Anthony Fauci on Thursday highlighted the importance of the U.S. quickly gaining control of the delta variant, warning continued community spread could lead to even more dangerous mutations of Covid-19, including those capable of evading the protection of vaccines.


“That will happen, George, if we don’t get good control over the community spread,” Fauci told “Good Morning America” anchor George Stephanopoulos during a Thursday interview on ABC News. 

Allowing the virus to spread through unvaccinated populations—as it is doing rapidly now—gives it “ample opportunity to mutate,” explained President Biden’s top medical advisor. 


“You may sooner or later get another variant, and it is possible that that variant might be in some respects worse than the already difficult variant we’re dealing with now,” Fauci said, referencing the delta variant, which experts say is significantly more infectious than other coronavirus strains.

He also emphasized that the virus can mutate regardless of whether people contracting the virus get symptoms. 

Vaccines may be effective at preventing serious disease and death with Covid-19’s current mutations, but this may not necessarily be true with future evolutions, Fauci emphasized. 


“People who say, ‘I don’t want to get vaccinated because it’s me and I’ll worry about me, I’m not having any impact on anybody else,’ that’s just not the case,” Fauci said. 



Fauci’s warning came as Moderna announced Thursday morning its Covid-19 shot is about 93% effective through six months after the second dose. Pfizer in July said the effectiveness of its jab steadily declines to about 84% six months after the final dose. Both vaccine makers have said they expect booster shots to be necessary ahead of the winter season, particularly due to the threat of the delta variant. 


The delta variant is driving surges in Covid-19 cases and hospitalizations that haven’t been seen since the early stages of the U.S.’s vaccine rollout. More than 51,000 Americans are now hospitalized with Covid-19, an 87% increase from two weeks ago, and cases have increased 131% to a daily average of nearly 100,000 during the same period, according to data compiled by The New York Times. Deaths have also shot up (by 65%) over the past two weeks, but—at 410—are still well below the country’s winter peak. Fauci has said while it’s “unquestionable” the delta variant is more infectious, it is “less clear” whether it actually causes more serious disease. 


Fauci warned in an interview with McClatchy on Wednesday the U.S. could begin reporting between 100,000 and 200,000 new cases each day if safety precautions and vaccinations don’t increase. “Remember, just a couple of months ago, we were having about 10,000 cases a day,” Fauci said. There are hopeful signs: After months of decline, the number of Americans getting the shot has been steadily increasing. White House Covid-19 data director Cyrus Shahpar announced Tuesday, as the U.S. surpassed a 70% partial inoculation rate, that the seven-day average of newly vaccinated people (441,000) was the highest in more than a month.

By Jemima McEvoy, Forbes Staff