New Yorkers’ blood samples reveal that some had coronavirus antibodies in late February – more than a week BEFORE the first case was announced in the state
- Researchers looked at 5,500 blood samples from patients at Mount Sinai Hospital in New York City from the week ending Feb. 9
- Coronavirus antibodies were detected in approximately 2.3% of the samples for the week ending February 23
- This means that the virus likely circulated in New York in late January or early February
- The first case in New York was confirmed on February 29 and announced by officials on March 1
- By April, more than 75% of blood samples from Mount Sinai patients tested positive for coronavirus antibodies
Blood samples from New Yorkers reveal some antibodies to the new coronavirus much earlier than previously believed, a study suggests.
Researchers found that about 10 to 20 of the roughly 500 residents in the Big Apple had developed an immune response in late February.
That’s about two percent of those tested at the time.
That’s about a week before the first case was confirmed on February 29 and announced on March 1 by Gov Andrew Cuomo.
The Icahn School of Medicine team on Mount Sinai says the findings could mean the virus was circulating in New York in late January or early February.
Coronavirus antibodies were detected in approximately 2.3% of samples for the week ending February 23, with 1.4% in one group (above) and 0.9% in another group
This means that the virus likely circulated in New York in late January or early February. Picture: A chart showing 0.9% of patients who tested positive for coronavirus antibodies for the week ending February 23
The first case in New York was confirmed on February 29 and announced by officials on March 1. Pictured: People wear a protective face mask outside The Smith on the Upper East Side in New York City, June 30
Published on the pre-print site for the study medRxiv.orgthe team analyzed approximately 5,500 plasma samples from patients at Mount Sinai Hospital in New York City.
Patients were divided into two groups. The first group was the ‘sentinel group’, ie those who visited the ER or were hospitalized with suspected coronavirus cases.
The second group was the ‘screening group’, which consisted of people who came for non-coronavirus visits, such as OB / GYN appointments, transplant surgery and so on.
For two weeks, starting the week ending February 9, the researchers found no antibodies to COVID-19, the virus-caused disease.
However, in the week ending Feb. 23, researchers found that 2.3 percent of the samples, between 10 and 20, contained antibodies.
About 1.4 percent of people in the sentinel group had antibodies, as did 0.9 percent of those in the screening group
This means that these New Yorkers were probably infected with the virus about two weeks before they recovered.
However, the first case was confirmed on Mount Sinai on February 29, and officials from New York announced the first case in the state – a Manhattan woman who had recently traveled to Iran – on March 1.
Another slight increase was observed for the week ending March 1, with approximately 5.2 percent of both groups testing positive for antibodies.
A spike among the sentry group, those suspected of having the virus, occurred in the week ending March 22 and occurred in the screening group for the week ending March 29.
By the week ending April 19, antibody prevalence was 58.1 percent among the sentinel group and 19.3 percent among the screening group.
Both are below the estimated 67 percent required to attain community immunity to the virus.
“These data may suggest an earlier than previously documented introduction of SARS-CoV-2 into the NYC metropolitan area,” the authors wrote.
It is unclear when the virus was first introduced, but it is much earlier than previously believed.
“You probably have it very early in February,” lead author Dr. Florian Krammer, an immunologist at the Icahn School of Medicine, told The New York Times.
“It looks like there was at least low circulation.”