Why are COVID-19 cases steadily dropping? If you can believe a Wall Street Journal opinion piece published last Friday, it’s part of a natural trend that will have the United States effectively virus-free and back to normal sometime in April. Not that everyone’s buying that.
“People should have a certain amount of skepticism about people making extremely confident predictions particularly outside of their field,” said Dr. Robin Colgrove, a virologist at Mt. Auburn Hospital in Cambridge.
The person making the confident predictions: a Johns Hopkins surgeon named Marty Makary. His basic theory is that when you take into account the number who will be vaccinated by April plus the segment of the population that got infected with COVID-19 but didn’t know it, you get ‘herd immunity.’ That’s the point at which it’s sparse pickings for pathogens looking for fresh bodies to infect.
Makary’s theory rests on the idea that those who got infected won’t get infected again because they’ve acquired natural immunity to COVID-19. But there’s a potential flaw in that reasoning and it has to do with the general nature of coronaviruses.
“Previously known coronaviruses typically have waning natural immunity,” Dr. Colgrove said. “And people are repeatedly reinfected year in and year out.”
It’s possible SARS-CO-V2 might be different, Dr. Colgrove said, but no one should count on that.
“I would be fine if the editorial had said, ‘We might have herd immunity by April,’ but to say that we will is really going beyond what the data justified,” Dr. Colgrove said.
“We know that, to some extent, people who get COVID-19 really are protected in the short term,” said Dr. Paul Sax, clinical director of the Division of Infectious Diseases at Brigham and Women’s Hospital in Boston. “But actually how long that immunity lasts is unclear, and we should just caution people that, with other coronaviruses, they can get them repeatedly.”
In his editorial, Makary estimates COVID-19 has infected 2/3 of the U.S. population. He arrives at this number using two variables: the Population Fatality Rate (deaths/total population) and the Infection Fatality Rate.
The problem with the latter variable is that it requires knowing the total number of cases of COVID-19, a quantity that is unknown due to the high incidence of cases with little to no symptoms. But Makary said that rate is, “about 0.23%.”
Boston 25 wanted to ask Makary how he arrived at some of his conclusions. But the Johns Hopkins media relations department told us he declined our request for an interview.
While Makary’s piece was technically written as an opinion, he states that it is rooted in fact:
“My prediction that COVID-19 will be mostly gone by April is based on laboratory data, mathematical data, published literature and conversations with experts.”
Some are concerned the public will take the piece as absolute fact.
“By Americans hearing this and not understanding the true value of it, it can lead us to go off the track that we are on – seeing the numbers going down, nationwide, and people really start throwing caution to the wind again,” said Michael Urban, a senior lecturer at the University of New Haven’s School of Health Sciences. “And then we’ll see a spike in return.”
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