Data show that less than 10% of the U.S. population carry COVID-19 antibodies

According to the report, less than 10% of the nationally representative samples of dialysis patients in the United States had antibodies to COVID-19. Investigation Published later last week Lancet..

Researchers at Stanford University and Ascend Clinical Laboratories have tested the sera of 28,503 patients treated at 1,300 dialysis centers in 1,013 counties in 46 states (32% of all counties in the United States) to test COVID- We estimated the number of people exposed to 19.

Substantial regional variation

They found that 8.2% to 9.4% of the samples had COVID-19 antibody. This indicates exposure to the virus. After comparing estimates with the number of cases at Johns Hopkins University, researchers found that about 9.3% of the U.S. population was infected, with regional variability ranging from less than 5% in the west to more than 25% in the northeast. I calculated. Less than 10% of antibody carriers were tested for COVID-19 during illness.

County residents who performed a lockdown in March with at least a 5% reduction in workplace visits were 60% less likely to be coronavirus antibody-positive in July than others.

Patients with early US coronavirus hotspots were significantly more likely to have evidence of previous infections (33.6% in New York, 17.6% in Louisiana, and 17.5% in Illinois). In contrast, residents of less affected neighboring states were less likely to carry antibodies (6.4% in Pennsylvania and 1.9% in Arkansas and Missouri, respectively).

The results of this study are similar to those of other recent studies in blockbuster countries such as China and Spain, indicating a low proportion of people with coronavirus antibodies, the authors said. ..

Co-author Julie Personnet, MD, said in The Lancet news release Despite the high incidence of coronavirus in the United States, “the number of people with antibodies is still small and has not yet achieved swarm immunity. It is more vulnerable until an effective vaccine is approved. We need to secure a good group. We have reached it with preventive measures. “

Wide racial and socio-economic disparities

People in the majority of black and Hispanic communities were two to four times more likely to have COVID-19 (4.8% vs. 11.3% to 16.3) compared to those who lived primarily in white areas. %). Patients living in low-income areas were twice as likely to be infected as their peers, and those living in densely populated communities were 10 times more at risk.

Researchers said dialysis patients are a suitable population for studying COVID-19 infections. Dialysis patients undergo monthly blood tests, which represent risk factors for other coronaviruses such as older, non-white, and low-income. The sample was representative of US dialysis patients by age, gender, race, ethnicity, and region.

Of the 2,292 patients with COVID-19 antibody, 1,322 (57.7%) were male and 1,765 (77%) were 45-79 years old. The sample has a high proportion of black patients living in neighborhoods with a non-white majority.

“This patient population is not only ethnically and socio-economically representative, but also one of the few groups of people that can be repeatedly tested,” lead author Shuchi Anand, MD, said in the release. “Because kidney disease is a subject of Medicare, we do not face many of the barriers to access to care that limit testing among the general population.”

Evaluation is not complete but useful

The authors noted that monthly antibody testing in dialysis patients is not complete, but is an excellent way to monitor disease trends, resource allocation, and the effectiveness of public health interventions. They recommended that COVID-19 public health measures focus on the black and Hispanic populations living in low-income, densely populated areas.

so Commentary In the same journal, Dr. Burnaby Flower and Dr. Christina Atchison of Imperial College London said that serum antibody tests produce a clearer picture of people with COVID-19 than cotton swab tests in symptomatic patients only. Said.

However, they found that extrapolation of antibody data from dialysis patients was incomplete because exposure to COVID-19 was likely to be higher than that of the general population by visiting medical facilities three times a week. I pointed out.

“But the concerns about sample applicability are bidirectional. Patients with comorbidities associated with end-stage renal disease may be less likely to develop a detectable antibody response,” wrote Flower and Atchison. ing. “They are also more likely to die of COVID-19 and are more likely to overrepresent unexposed serum-negative survivors in the sample.”