An estimated 13.9% of the New Yorkers have likely had Covid-19, according to preliminary results of coronavirus antibody testing released by Gov. Andrew Cuomo on Thursday.
The state randomly tested 3,000 people at grocery stores and shopping locations across 19 counties in 40 localities to see if they had the antibodies to fight the coronavirus, indicating they have had the virus and recovered from it, Cuomo said.
With more than 19.4 million residents, according to U.S. Census data, the preliminary results indicate that at least 2.7 million New Yorkers have been infected with Covid-19.
The results differed across the state with the largest concentration of positive antibody tests found in New York City at 21.2%. On Long Island, 16.7% of the people tested were positive and in Westchester and Rockland counties, 11.7% of the tests were positive. Westchester County is where the state's first major outbreak originated. The Covid-19 pandemic across the rest of the state is relatively contained with just 3.6% of positive test results.
"What we found so far is that the statewide number is 13.9% tested positive for having the antibodies," he said. "They were infected three weeks ago, four weeks ago, five weeks ago, six weeks ago, but they had the virus, they developed the antibodies and they are now recovered."
While Covid-19 deaths across the state have begun to level off, the "number of lives lost is still breathtakingly tragic," Cuomo said. The state's mortality rates remains persistently high, at 7.4% with at least 19,453 fatalities and 263,754 confirmed cases, according to data compiled by Johns Hopkins University. The antibody testing indicates that the actual death rate is far lower, less than 1%, Cuomo said.
The testing results also may be artificially high because "these are people who were out and about shopping," Cuomo added. "They were not people who were in their home, they were not people isolated, they were not people who were quarantined who you could argue probably had a lower rate of infection because they wouldn't come out of the house."
While Cuomo cautioned that the data was preliminary, he also said the 3,000 test sample was a "significant data set."
On Sunday, Cuomo said the U.S. Food and Drug Administration approved the state's antibody test that will provide the "first true snapshot" of how many people have been infected with Covid-19 in New York. State officials don't know the true number of infections because they haven't been able to conduct diagnostic coronavirus testing on a large scale, Cuomo said.
Global health officials have questioned the reliability of antibody testing, however, and whether it can accurately determine whether someone is immune to the disease. The World Health Organization said on Friday that there's no evidence serological tests can show whether a person has immunity or is no longer at risk of becoming reinfected.
Dr. Mike Ryan, executive director of the WHO's emergencies program, said scientists are also studying how long any potential immunity might last.