New York City on Tuesday released more than 1.46 million coronavirus antibody test results, the largest number to date, providing more evidence of how the virus penetrated deep into some lower-income communities, while passing lighter across rich portions of the city.
In one postcode in Queens, more than 50 per cent of the people tested had antibodies found to be remarkably high. But no zip code south of 96th Street in Manhattan had a positive rate of more than 20 percent.
In the city, more than 27 percent of the tests had positive antibody results. The municipality with the highest rate was the Bronx, at 33 percent. Manhattan had the lowest rate, at 19 percent.
The data is likely to renew the debate over whether some neighborhoods or communities in New York City might be close to herd immunity – the point at which enough people have immunity that the virus is no longer able to spread much within a community.
To date, public data for antibodies in New York City have been limited. CityMD, which plays a key role in the city’s test program, had shared some data from its network of emergency care clinics.
Prime Minister Andrew M. Cuomo’s office had released some details of a survey – which tested some 28,419 people in the state – that suggested that roughly 21.6 percent of New York City residents had antibodies. .
But the data on Tuesday released antibodies are on a much larger scale, and include more than 15 percent of New York City residents. It included all test results of antibodies reported to the New York City Department of Health.
“This gives us a sense of a deeper level of the extent of the penetration of the infection into the population,” said Wafaa El-Sadr, a professor of epidemiology at Columbia University.
Here’s what it means:
Some severely affected areas may sail better in a second wave
Much remains unknown about the degree of protection against Covid-19 that antibodies can provide, or how long that protection may last. But the weeks with more residents infected following the outbreak of New York in March and April may be less likely to be among the hardest hit in a second wave.
On the other hand, neighborhoods in which a few residents are infected may find themselves perhaps more vulnerable in the event of a resurrection.
Some researchers have expressed the hope that herd immunity to the new coronavirus requires only about half of the people in a given community to have immunity – while others have suggested a higher threshold, such as 70 percent.
Of course, weeks are not apart, and even under the most optimistic predictions, most neighborhoods – and millions of New Yorkers – remain vulnerable to infection in a second wave.
However, the relatively high prevalence of antibodies may explain in part why New York has not seen a major uptick in cases in recent months, even as the city began to reopen and some New Yorkers began to relax their social distance.
In interviews, epidemiologists have generally expressed surprise and relief at the rate of new infections in New York City, raising it to a variety of measures: widespread use of face masks, adherence to recommendations for social distance and the continuing ban on food and bars inside.
“If antibody tests accurately identify those who are infected and if these antibodies are protective, some communities in NYC are close to developing herd immunity, such as Corona in Queens, for example,” Professor El-Sadr wrote in an email. “That’s an engaging thought.”
The results released on Tuesday showed that 51.6 percent of people who tested in one ZIP code in Corona tested positive for antibodies.
New York City Health Commissioner Dr. Dave Chokshi warned against drawing too many conclusions from anti-antibody rates, as there are still many pressing questions about immunity.
“Staying vigilant about precautionary measures such as hand washing, distancing, face covering and staying home when sick is essential to keep transmission low,” he said.
Weeks with large households were vulnerable
The heaviest hit code in the city – 11368 – was the one in Corona, a predominantly Spanish neighborhood with many construction workers and restaurant staff. Many had to work through the severe pandemic, increasing their risk of infection.
About 23 percent of the residents in the zip code have received an antibody test.
That part of Queens has a particularly high rate of household population, which may also partly explain the high positive anti-antibody level. Experts have said that transmission within households is a leading driver of the spread of the disease.
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Frequently Asked Questions
Updated August 17, 2020
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Why does standing six feet apart help others?
- The coronavirus spreads primarily by drips from your mouth and nose, especially when you cough or sneeze. The CDC, one of the organizations using that measure, bases its six-foot recommendation on the idea that most large drops that expel people when they cough or sneeze fall within six feet to the ground. But six feet has never been a magic number that guarantees complete protection. Noses, for example, can launch drops much farther than six feet, according to a recent study. It’s a rule of thumb: you need to be the safest to stand six feet apart, especially when the wind is blowing. But always wear a mask, even if you think you are far enough apart.
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I have antibodies. Am I immune now?
- At the moment, that probably seems like at least several months. There have been horrific accounts of people suffering from what appears to be a second bolt of Covid-19. But experts say these patients may have a prolonged course of infection, with the virus taking a slow toll weeks to months after initial exposure. People infected with the coronavirus typically produce immune molecules called antibodies, which are protective proteins made in response to an infection. These antibodies may only last two to three months in the body, which may seem worrying, but that is perfectly normal after an acute infection progresses, said Dr. Michael Mina, an immunologist at Harvard University. It could possibly get the coronavirus back up, but it is highly unlikely that it would be possible in a short window of time from initial infection or the second time safe.
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I am a small business owner. Can I get relief?
- The incentive bills introduced in March provide assistance to the millions of American small businesses. Those eligible for support are non-profit companies and organizations with less than 500 workers, including sole proprietorships, independent contractors and freelancers. Some larger companies in some sectors are also eligible. The assistance provided, which is managed by the Small Business Administration, includes the Paycheck Protection Program and the Economic Damage Disaster Program. But many people have not seen payments yet. Even those who have received help are confused: the rules are draconian, and some are stuck on money they do not know how to use. Many small business owners get less than they expected or heard nothing at all.
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What are my rights if I am worried about returning to work?
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What will school look like in September?
- It is unlikely that many schools will return to a regular schedule this fall, requiring the grinding of online learning, easy childcare and stunted workdays to continue. The two largest public school districts of California – Los Angeles and San Diego – said on July 13 that instruction will be remote only in the fall, citing concerns that growing coronavirus infections in their areas pose too great a risk to students and teachers. Together, the two districts enroll about 825,000 students. They are the largest in the country to date to abandon plans for even a partial physical return to classes when they reopen in August. For other districts, the solution will not be an all-or-nothing approach. Many systems, including the nation’s largest, New York City, are creating hybrid plans that include some days attending classrooms and other days online. There is no national policy yet, so check regularly with your municipal school system to see what is happening in your municipality.
The zip code with the second highest rate of positive antibody testing was near Borough Park in South Brooklyn. There, more than 46.8 percent of antibody tests were positive.
Borough Park is home to many Hasidic Jews, a particularly harsh demographic. Large households are common, and the tight, communal lifestyle was probably a factor as well. Many Hasidic Jews fell ill in early March, right after Purim – a holiday of joyous celebration, full of feasting and mingling.
The lowest rate – 12.4 percent – came from a thin zip code in Queens, consisting of just a few blocks to the waterfront in Long Island City. The next lowest rates were in Manhattan, where in several ZIP codes less than 13 percent of the people tested had antibodies. The lowest Manhattan rates – 12.6 percent – occurred in one ZIP code on the Upper East Side and another on the Upper West Side.
In Brooklyn, the zip code with the lowest rate of positive antibody tests – 13.2 percent – covers a large portion of Park Slope, a wealthy and mostly white neighborhood.
Children were most likely antibodies.
Among various age groups, those 17 and under were most likely to have antibodies, with 32.6 percent of their tests returning positive.
But the data may not add much value to the debate over school reopening, as children were also by far the least likely age group to test – about 6,500 per 100,000 people tested, compared to nearly 27,500 per 100,000 people who were tested tests in the 45-64 age group.
The age results were also not separated by weeks.
People aged 45 to 64 years were more likely to have a positive antibody percentage (28 percent) than adults in other age cohorts.
A higher percentage of men (28 percent) tested positive for antibodies than women (25 percent).
In ZIP codes classified as high poverty rates, more than 30 percent of the tests had antibodies. In those with lower poverty rates, about 18.5 percent of the people tested had antibodies.
The data did not include distribution by race or ethnicity. Other data have shown that Black and Hispanic New Yorkers have significantly higher rates – when adjusted for age – of hospitalization or dying from Covid-19 than white people.
The data still has limitations
The accuracy of antibody testing varies widely. Moreover, most antibody tests were done for people who searched for them, meaning that those tested were a selection group and not a random sample.
It also turns out that in some weeks New Yorkers with lower rates of infection were more likely to test for antibodies.
In some rich and for the most part white ZIP codes in Manhattan, about 30 percent of people may have passed an antibody test. But in Corona, for example, where the positive rate was highest, less than a quarter of people were tested.
