CDC Says Delta Variant Makes Up an Estimated 83 Percent of US Cases

Politics|The Delta variant makes up an estimated 83 percent of U.S. cases, the C.D.C. manager says.

• July 20, 2021, 4:10 p.m. ET

The highly infectious Delta variant present accounts for an estimated 83 percent of caller coronavirus cases successful the United States — a “dramatic increase” from aboriginal July, when it crossed the 50 percent threshold to go the ascendant variant successful this country, the manager of the Centers for Disease Control and Prevention said Tuesday.

In immoderate regions, the percent is adjacent higher — peculiarly wherever vaccination rates are low, Dr. Rochelle Walensky, the C.D.C. director, said during a Senate wellness committee hearing. Two-dose vaccines person been shown to beryllium effectual against the Delta variant but questions person been raised astir Johnson & Johnson’s single-dose regimen against Delta. While astir 60 percent of U.S. adults are afloat vaccinated, little than fractional of the full U.S. colonisation is.

She said the C.D.C. would update its website aboriginal Tuesday to bespeak the caller estimation of Delta cases, which the bureau derives from cistron sequencing of caller coronavirus cases.

The caller fig comes arsenic caller cases have been rising crossed the United States, though cases, hospitalizations and deaths stay a fraction of their peaks. Still, public wellness experts are watching the increases with heavy concern and Dr. Walensky warned past week that “this is becoming a pandemic of the unvaccinated.” The seven-day mean present shows much than 35,000 caller regular cases, up from astir 11,000 a time not agelong ago, according to a New York Times database.

Tuesday’s proceeding was contentious astatine times. Senator Mitt Romney, Republican of Utah, pressed Dr. Janet Woodcock, the acting commissioner of the Food and Drug Administration, connected erstwhile the F.D.A. would authorize booster shots — and was not blessed erstwhile she could not supply a circumstantial answer. Federal wellness officials have said booster shots are not indispensable present and person pressed Pfizer for much evidence.

Other Republicans clashed with witnesses implicit matters including disguise mandates, booster shots for Covid-19 vaccines and “gain of function” probe designed to place familial mutations that could marque a microorganism much powerful.

Senator Rand Paul, Republican of Kentucky, escalated his long-running attacks connected Dr. Anthony S. Fauci, President Biden’s apical aesculapian advisor for the coronavirus pandemic, and accused Dr. Fauci of committing a transgression by lying to Congress successful May erstwhile helium told senators that the National Institutes of Health did not money “gain of function” probe astatine a laboratory successful Wuhan, China, the epicenter of the pandemic’s aboriginal days.

Dr. Fauci, successful turn, accused the legislator of falsely implying that the N.I.H. is someway liable for hundreds of thousands of deaths from the pandemic — an bonzer speech for the Senate, wherever witnesses astir ever defer to lawmakers.

“I person ne'er lied earlier Congress and I bash not retract that statement,” Dr. Fauci declared, adding, “Senator Paul, you bash not cognize what you are talking about, rather frankly, and I privation to accidental that officially.”