How the Untested are Driving Us to Herd Immunity by April
Given the shelf space given to the pandemic, I thought a look at the recent Wall Street Journal op-ed by Dr. Makary titled, “We’ll Have Herd Immunity by April,” would be useful.
This conclusion about herd immunity being reached in April is based on:
“laboratory data, mathematical data, published literature, and conversations with experts. But it’s also based on direct observation of how hard testing has been to get, especially for the poor. If you live in a wealthy community where worried people are vigilant about getting tested, you might think that most infections are captured by testing. But if you have seen the many barriers to testing for low-income Americans, you might think that very few infections have been captured at testing centers. Keep in mind that most infections are asymptomatic, which still triggers natural immunity.”
And while many shy away from the term “herd immunity,” it is central to all pandemic strategies, either through “viral spread or vaccination,” as Dr. Makary states:
Many experts, along with politicians and journalists, are afraid to talk about herd immunity. The term has political overtones because some suggested the U.S. simply let Covid rip to achieve herd immunity. That was a reckless idea. But herd immunity is the inevitable result of viral spread and vaccination. When the chain of virus transmission has been broken in multiple places, it’s harder for it to spread—and that includes the new strains.
Herd immunity has been well-documented in the Brazilian city of Manaus, where researchers in the Lancet reported the prevalence of prior Covid-19 infection to be 76%, resulting in a significant slowing of the infection.
Regardless of the gentle sensitivities around the term herd immunity, the refusal by the media and medical cognoscenti to acknowledge the impact of untested, and therefore, unknown asymptomatic infections on herd immunity has prolonged this crisis.
Willfully excluding this information is becoming more difficult, given recent study results:
Antibody studies almost certainly underestimate natural immunity. Antibody testing doesn’t capture antigen-specific T-cells, which develop “memory” once they are activated by the virus. Survivors of the 1918 Spanish flu were found in 2008—90 years later—to have memory cells still able to produce neutralizing antibodies.
Researchers at Sweden’s Karolinska Institute found that the percentage of people mounting a T-cell response after mild or asymptomatic Covid-19 infection consistently exceeded the percentage with detectable antibodies. T-cell immunity was even present in people who were exposed to infected family members but never developed symptoms. A group of U.K. scientists in September pointed out that the medical community may be under-appreciating the prevalence of immunity from activated T-cells.
The rote-repeated phrase “we don’t know how long antibodies last” is misleading at best and also irrelevant, given human memory cells’ ability to produce antibodies on demand for any specific virus previously defeated.
Policymakers should not be blind to the impact of the untested and, therefore, the number of unknown asymptomatic cases of covid and its impact on herd immunity.