US will reach herd immunity for coronavirus by April: Johns Hopkins professor

Updated March 4

Dr. Marty Makary is a professor at the prestigious John Hopkins School of Medicine. He said on Friday when being interviewed that he believed that the US is very close to having herd immunity.

"U.S. Will Reach Herd Immunity For COVID-19 By April, Johns Hopkins Doctor Says"

Makary had this to say in the interview with the Wall Street Journal:

"There is reason to think the country is racing toward an extremely low level of infection. As more people have been infected, most of whom have mild or no symptoms, there are fewer Americans left to be infected. At the current trajectory, I expect Covid will be mostly gone by April, allowing Americans to resume normal life."

Makary elaborated on why herd immunity is imminent:

"In large part because natural immunity from prior infection is far more common than can be measured by testing. Testing has been capturing only from 10% to 25% of infections, depending on when during the pandemic someone got the virus. Applying a time-weighted case capture average of 1 in 6.5 to the cumulative 28 million confirmed cases would mean about 55% of Americans have natural immunity,"

The medical expert continued, "Now add people getting vaccinated. As of this week, 15% of Americans have received the vaccine, and the figure is rising fast. Former Food and Drug Commissioner Scott Gottlieb estimates 250 million doses will have been delivered to some 150 million people by the end of March."

New coronavirus infections in the US peaked at the end of the year, and have been steadily declining ever since.

However, other experts claim it will take longer for the US to reach herd immunity. Makary's claims were disputed by other medical professionals. An additional review explained that, Makary's claim is based in the idea that up to 66 percent of Americans have already had COVID-19. However, this may not be accurate.

"The author uses a value of 15.4 percent (1/6.5), which produces a very different answer than if the author had used his other proposed value of 25 percent (1/4),” said Marm Kirkpatrick, a professor at the University of California Santa Cruz. "Instead of the 55 percent seroprevalence claimed, seroprevalence would be 34 percent. The fraction of infections detected by testing may even be higher than 25 percent, which would produce an even lower estimate of seroprevalence."

Virologist Angela Rasmussen said that Makary "misrepresented a study by Sekine et al. on T cells: 'T cell immunity is presented [in the Wall Street Journal opinion piece] as being an indicator of protective immunity […] this is an incorrect interpretation of the data cited about T cells to support that assertion.'"

Dr. Ali Mokdad, Chief Strategy Officer of Population Health at the University of Washington's Institute for Health Metrics and Evaluation (IHME), said that CDC surveys indicate that 20 percent of Americans have had the virus, and his prediction is that 20 percent of Americans will be vaccinated by April.

"So the best-case scenario is the United States would be around 40 percent... That's not herd immunity," Mokad said.

The CDC has reported that as of March 3, nearly 16 percent of Americans have been vaccinated. The US is vaccinating citizens at a rate of 1.7 million people per day.