Although the media claims that “We cannot turn around COVID,” the number of COVID-19 cases, new hospitalizations, and deaths nationwide peaked and began to decline in early September. The combination of this milestone, new findings from the Centers for Disease Control and Prevention that show widespread levels of vaccination and natural immunity, and improved availability of treatments suggest that, outside of isolated pockets, COVID-19 is likely will become a health risk to the United States.
The CDC looked for evidence of previous infection or vaccination in the blood of approximately 1.5 million blood donors nationwide between July 2020 and May 2021. Based on the antibodies found in the specimens, they to be able to distinguish between those who had been vaccinated. and those with antibodies derived from the infection. At the end of May, the combined seroprevalence of vaccine and infection (indicating the proportion of the population with antibodies and some level of immune protection) was 83 percent for those over 16 (those under 16 cannot donate blood). More than 20 percent had antibodies indicating previous infection and recovery. Based on infection-induced seroprevalence, the researchers estimated that there were actually 2.1 infections for every COVID-19 case reported.
Now, after the increase of the Delta variant, the number of confirmed cases of COVID-19 (all ages) exceeds 40 million, or 8 million more than on May 31st. Applying multiple 2.1 of the blood donation study to the entire population results in a real number of cases and people with natural immunity of 84 million, or 25% of the population.
In addition, 177 million people are fully vaccinated, or 53 percent of the total population and 34 million more than at the end of May. An additional 10 percent of the population has received a single dose, which provides some protection, albeit less than the two full doses.
Although there is an overlap because some previously infected people have been vaccinated, approximately 80% of the country has a vaccine or natural immunity. Both types of immunity provide effective protection against COVID-19. The risk of advanced infections among vaccinated individuals is small, and when they do occur, vaccines remain effective in preventing serious disease, even for the Delta variant. The CDC also recognizes that reinfection of patients recovered with COVID-19 is rare.
Although some vaccines induce a better immune response than natural infection, experts often say that “natural infection almost always causes better immunity than vaccines.” This seems to be true with COVID-19.
A new Israeli study confirms that natural immunity to COVID-19 is superior to vaccine-induced immunity, even with the Delta variant. Between June 1 and August 14, when Delta was dominant in Israel, the risk of infections was 13 times higher for vaccinated people than for previously unvaccinated infected people when infection or vaccination it had occurred four to seven months earlier. The risk of symptomatic advanced infections was 27 times higher. Although natural immunity decreased slightly over time, vaccinated people had a six-fold higher risk of infection and a seven-fold higher risk of symptomatic disease than infected people up to ten months before starting vaccinations.
A previous study conducted at the Cleveland Clinic with more than 52,000 health care workers from December 16, 2020 to May 15, 2021 (just before Delta became dominant in the United States) found that both natural immunity and vaccine immunity provide good protection against infections. None of the 1,359 previously infected subjects who remained unvaccinated were reinfected. Their risk of infection was not higher than that of vaccinated people, whether they were infected or not.
In addition, natural immunity so far appears to be at least as long-lasting as vaccine immunity. Even before vaccines became widely available, studies indicated that four types of immune memory persist for more than six months after infection. The results from the Cleveland Clinic suggested that natural immunity provides protection against reinfection for ten or more months, which led the authors to conclude that patients with previously infected COVID-19 are “unlikely to benefit” from the vaccination. Another study found that convalescent individuals maintained immune protection for 12 months without being vaccinated, although protection could be improved with vaccination.
COVID-19 treatments have also improved. Several versions of monoclonal antibodies have been authorized and are now readily available. These drugs are highly effective in preventing early COVID-19 from progressing, reducing the risk of hospitalization or death by 70% to 85%, especially for people at high risk of developing serious illness. Steroids and new more effective ICU protocols have also resulted in lower mortality from COVID-19.
Of course, some super variant could emerge that escapes the vaccine and natural immunity and is resistant to treatments, in the same way that the appearance of Delta upset many predictions. There is no way to predict these developments. But even the highly contagious variant of Delta, which raised estimates of the percentages needed for herd immunity, did not shy away from vaccine protection and natural immunity. Delta morbidity and mortality have been highly concentrated among those who had no vaccine or natural immunity.
Ending the COVID-19 pandemic does not mean that the virus will be eradicated or that there will be no new cases. It means that serious illness and death resulting from infection with a virus that has probably become endemic will become rare. Our innovative free market economy has provided new vaccines and therapies in record time. Thanks to this and the undervalued but important phenomenon of natural immunity, we are on most of the road.
Joel Zinberg, MD, JD, is a senior member of the Competitive Enterprise Institute and an associate professor of surgery at Icahn Mount Sinai School of Medicine in New York City.
Reprinted with permission from City Journal