https://www.newsmax.com/health/health-news/vaccine-infection-cdc/2021/09/02/id/1034866/With an interesting headline of "CDC Study: COVID Infection Offers Protection Similar to Vaccines"
But when clicking into the study and the CNN report on it, this is not at all what the study is about. The study title is "Estimated US Infection- and Vaccine-Induced SARS-CoV-2 Seroprevalence Based on Blood Donations, July 2020-May 2021" and the headline of the section on the CNN page is "Survey: More than 80% of Americans 16 and older have immunity". The discussion is entirely about how prevalent antibodies are based on a survey of blood donations. It includes one sentence that mentions the comparison between the immunity conferred by the two. "Several large studies have shown that among individuals who are seropositive from prior SARS-CoV-2 infection, COVID-19 incidence is reduced by 80% to 95%, similar to vaccine efficacy estimates." This does not seem to be drawing any conclusion of its own about the comparison but rather mentioning it as a side point to the conclusions of this study.
Overall, it seems to be a very interesting survey.
This is the CNN writeup
https://www.cnn.com/2021/09/02/health/us-coronavirus-thursday/Survey: More than 80% of Americans 16 and older have immunity
More than 80% of Americans 16 and older have some level of immunity against the coronavirus, mostly through vaccination, a survey of blood donations indicates.
The survey, led by the CDC, also indicates that about twice as many people have been infected with the virus as have been officially counted. More than 39 million Americans have been diagnosed with coronavirus infection since the pandemic started in 2020.
The team, led by the CDC's Dr. Jefferson Jones, set out to determine how close the US might be to some kind of herd immunity -- although they do not claim to have any kind of handle on that yet.
They worked with 17 blood collection organizations working in all 50 states plus Washington, DC, and Puerto Rico to test blood covering 74% of the population. In the end, they tested about 1.4 million samples.
In July 2020, before any vaccine was available, 3.5% of samples carried antibodies to SARS-CoV-2, the virus that causes Covid-19. That rose to 11.5% by December, they reported in the medical journal JAMA. By May, 83.3% of samples had antibodies to the virus, most of them from vaccination.
And while in July 2020, blood surveillance indicated the US was only counting one infection out of every three true infections, that fell to one in two a year later.
This was all pre-Delta, the researchers caution. Plus, they didn't measure the other part of the human response -- one involving cells known as T-cells -- and one that might induce broader immunity. But knowing who has antibodies can help inform public health efforts.
"Several large studies have shown that among individuals who are seropositive from prior SARS-CoV-2 infection, COVID-19 incidence is reduced by 80% to 95%, similar to vaccine efficacy estimates," they noted.
"The study will continue until at least December 2021, and results will be made available on the CDC's website," they wrote.
