Trump Allies Say the Virus Has Almost Run Its Course. ‘Nonsense,’ Experts Say.

In the last week, leading epidemiologists from respected institutions have, through different methods, reached the same conclusion: About 85 to 90 percent of the American population is still susceptible to SARS-CoV-2, the virus causing the current pandemic.

The number is important because it means that “herd immunity” — the point at which a disease stops spreading because nearly everyone in a population has contracted it — is still very far off.

The evidence came from antibody testing and from epidemiological modeling. At the request of The New York Times, three epidemiological teams last week calculated the percentage of the country that is infected. What they found runs strongly counter to a theory being promoted in influential circles that the United States has either already achieved herd immunity or is close to doing so, and that the pandemic is all but over. That conclusion would imply that businesses, schools and restaurants could safely reopen, and that masks and other distancing measures could be abandoned.

“The idea that herd immunity will happen at 10 or 20 percent is just nonsense,” said Dr. Christopher J.L. Murray, director of the University of Washington’s Institute for Health Metrics and Evaluation, which produced the epidemic model frequently cited during White House news briefings as the epidemic hit hard in the spring.

That belief began circulating months ago on conservative news programs like those of Rush Limbaugh and Laura Ingraham. It has been cited several times by Dr. Scott W. Atlas, President Trump’s new pandemic adviser. It appears to be behind Mr. Trump’s recent remarks that the pandemic is “rounding the corner” and “would go away even without the vaccine.”  ...