A recent survey on blood donations has shown that more than 80% of Americans over the age of 16 have some level of immunity to COVID-19, a figure that could have massive implications for the country’s public health policy.
The survey, conducted by researchers at the U.S. Centers for Disease Control and Prevention, also found that twice as many people were infected with the pathogen as those who have been officially counted, CNN reported. As of Thursday, more than 39 million Americans have tested positive for the virus.
According to CNN, the CDC team, led by Dr. Jefferson Jones, began the study to “determine the extent to which the United States could be facing some kind of herd immunity.” Although the news media certainly mentioned the researchers “they still do not claim to have any control.”
They accomplished the task by testing about 1.4 million blood samples provided by 17 different blood collection organizations in the 50 states.
In studying the samples, the team found that between July 2020 and May 2021, the percentage of blood samples carrying SARS-CoV-2 ear antibodies increased from 3.5% to 83%. , 3% during this time period.
Based on a sample of blood donations in the United States from July 2020 to May 2021, it is estimated to be # SARSCoV2 … https://t.co/OyWffTBmRL
– JAMA (@JAMA)1630598403.0
The researchers highlighted the prominent role that widespread vaccination efforts have played in increasing the percentage. Although they also noted that previous infection provides similar protection against the virus.
“Several large studies have shown that among HIV-positive people with a previous infection with SARS-CoV-2, the incidence of COVID-19 is reduced by 80% to 95%, similar to estimates of the effectiveness of vaccine, ”they wrote.
The researchers acknowledged that their study has “several limitations,” however, which include that all testing occurred before the full appearance of the Delta variant in the United States.
It should be noted that a recent study in Israel found that unvaccinated people with a previous infection were 13 times less likely to get the Delta variant than people who were vaccinated without a previous infection.
Similarly, the study focused only on the presence of antibodies in blood samples and did not measure other immune responses, including those affecting memory T cells.
“Additional research is needed on the association between combined seroprevalence, protection, and herd immunity,” the researchers wrote.
“The study will continue at least until December 2021 and the results will be published on the CDC website,” they added.