by Marty Makary, MD
Anthony Fauci has been saying that the country needs to vaccinate 70% to 85% of the population to reach herd immunity from Covid-19. But he inexplicably ignores natural immunity. If you account for previous infections, herd immunity is likely close at hand.
Data from the California Department of Public Health, released earlier this month, show that while only 8.7% of the state’s population has ever tested positive for Covid-19, at least 38.5% of the population has antibodies against the novel coronavirus. Those numbers are from Jan. 30 to Feb. 20. Adjusting for cases between now and then, and accounting for the amount of time it takes for the body to make antibodies, we can estimate that as many as half of Californians have natural immunity today.
The same report found that 45% of people in Los Angeles had Covid-19 antibodies. Again, the number can only be higher today. Between “half and two-thirds of our population has antibodies in it now,” due to Covid exposure or vaccination, Mayor Eric Garcetti said Sunday on “Face the Nation.” That would explain why cases in Los Angeles are down 95% in the past 11 weeks and the positivity rate among those tested is now 1.7%.
Undercounting or removing the many Americans with natural immunity from any tally of herd immunity is a scientific error of omission. When people wonder why President Biden talks about limiting Fourth of July gatherings, it’s because his most prominent medical adviser has dismissed the contribution of natural immunity, artificially extending the timeline.
Many physicians believe that vaccinated immunity will prove more durable than natural immunity. I agree, and I think everyone should get vaccinated. But after a year of millions of Covid-19 cases in the U.S., it’s clear that reinfections are rare. Natural immunity is real and shouldn’t be ignored.
Dr. Fauci’s vaccination-only path to herd immunity has significantly influenced the national conversation. KNBC-TV in Los Angeles has a county-by-county vaccine tracker showing a bar graph of the percentage of Californians vaccinated, with the zone 70% to 85% labeled “herd immunity.” Currently, it’s at 26%. The false construct does create a greater urgency for everyone to get vaccinated. But it also creates false justification for continued excessive restrictions on freedom. And it raises the possibility that authorities are misallocating the limited vaccine supply by failing to direct it toward people without natural antibodies.
Rochelle Walensky, director of the Centers for Disease Control and Prevention, has joined Dr. Fauci in playing down natural immunity. In a Feb. 17 interview with the Journal of the American Medical Association, she suggested that up to 20% of the population might have had Covid-19. A study of antibody prevalence published soon after noted that 14% of New Yorkers had antibodies in September, before the state’s fall and winter surge. According to the more recent California data, Dr. Walensky underestimated the prevalence of natural immunity by half.
Some experts claim they don’t talk about natural immunity because we shouldn’t trust it. But a recent Public Health England study found that less than 1% of 6,614 healthcare workers who had Covid-19 developed a reinfection within five months—even though many of them work with Covid patients. Other experts believe natural immunity is powerful. “Natural immunity after Covid-19 infection is likely lifelong, extrapolating from data on other coronaviruses that cause severe illness, SARS and MERS,” says Monica Gandhi, an infectious-disease physician and professor at the University of California.
Dr. Fauci has said that we don’t have good data on natural immunity. That is largely because his own National Institutes of Health has done little to answer this and other important clinical questions. The NIH and CDC, which together receive more than $40 billion a year from taxpayers, should have focused on answering the most basic Covid-19 clinical questions that affect Americans. If we say we’re going to follow the science, then we need to be willing to consider all the data.
Dr. Makary is a professor at the Johns Hopkins School of Medicine, Bloomberg School of Public Health and Carey School of Business. He is chief medical adviser to Sesame Care and author of “The Price We Pay.”
[I have a suspicion that Makary’s was induced to add these words in order to get his Op-Ed published: “Many physicians believe that vaccinated immunity will prove more durable than natural immunity. I agree…” It doesn’t really fit with the rest of the piece. Perhaps this is the best you can expect in the age of cancel culture?