The number of new cases of coronavirus in New York City has remained alarmingly and stubbornly high for weeks, even as tens of thousands of people are vaccinated daily.
A likely reason is that more contagious variants have supplanted the original forms of the virus, public health officials said, accounting for more than 75 percent of new cases, according to a recent analysis.
The health department publishes every week the results of a sample of up to 1500 advanced cases, giving a snapshot of the nationwide variants that are increasing.
Until this week, the city has not said which variants are most common in which neighborhoods. But newly available zip code level information provides some insight into the mix of variants circulating in the area.
The information serves as a vivid reminder that the dynamics of the New York epidemic have changed in recent months, and that the original forms of the virus are increasingly uncommon in the city.
“It makes something that is quite abstract and perhaps less accessible, much more tangible to people,” said Dr. Denis Nash, an epidemiologist at the CUNY Graduate School of Public Health and Health Policy, said about the data. “The landscape is changing fast.”
The variants spread
A variant first discovered in New York, B.1.526, has spread more widely in the city than any other to date. There is also a significant increase in cases involving the B.1.1.7 variant, which was first detected in Britain last year and now accounts for almost 30 per cent of the new cases followed up in New York City .
The B.1.1.7 variant has driven new increases in diseases from Poland to Michigan. It is estimated to be 60 percent more contagious and two-thirds more deadly than the original form of the virus. This variant is now the major source of new infections in the United States and in Europe.
But not in New York City, where B.1.526 remains the most common variant, containing about 45 percent of cases from the fourth week of March.
Many questions about B.1.526, such as whether it causes serious diseases or can evade protection by the vaccines, remain unanswered.
About which is more contagious – B.1.1.7 or B.1.526 – health officials are not yet sure. “We do not have enough information to see this at the moment,” said the city’s health commissioner, Dr. Dave Chokshi, said.
In Queens, Manhattan and Brooklyn, the B.1.526 variant accounted for more than 50 percent of all cases following March 16 to April 1. In the Bronx, the share of B.1.526 was 61 percent.
One of the few places where B.1.1.7 appears to be responsible for most cases has been along the southern tip of Staten Island, which has been struggling with high property taxes for months and is currently home to some of the highest positivity rates in the city.
Across Staten Island, B.1.1.7 accounted for 40 percent of the new cases that followed between March 16 and April 1. In Queens, Brooklyn and Manhattan, B.1.1.7 represents a smaller share, accounting for 26 to 29 percent in these neighborhoods. . In the Bronx, B.1.1.7 represented only 23 percent of the cases that followed.
Despite the dominance of variants, hospitalizations in the city have not increased in recent weeks, and are actually declining slightly. And business was stable, albeit at a high level. “For me, it’s reassuring,” said Dr. Wafaa El-Sadr, an epidemiologist at the Mailman School of Public Health, at Columbia University, said. “We may see the beginnings of a vaccine effect.”
The data has limitations
In a given week, about one to two thousand positive cases of coronavirus in New York City are sequentially determined – that is, the genetic material of the virus is examined for mutations. This represents approximately between four and eight percent of new business in New York. The majority of cases are followed up in a laboratory in Long Island City operated by Opentrons, a robotics company.
At The Times’ request, CEO Jonathan Brennan-Badal shared the zip code level data for about 7,500 conclusions, explaining that the information could help identify where the need for more resources – including testing and vaccinations – is greatest. .
The city health department uses the ranges from this lab, known as the Pandemic Response Lab, as the basis for the weekly sample that measures the appearance of each variant.
But even with thousands of samples following in succession, the data still have significant limitations. Most of the coronavirus samples come from the city’s public hospital system and city-sponsored test sites. It receives many samples from some neighborhoods, but few from others.
“The limited number of variants that have been followed up so far makes it difficult to conclude whether some neighborhoods are being hit harder than others,” said Dr. El-Sadr said.
Each dot on the density maps above is placed in the zip code of a New Yorker whose coronavirus sample was set up in the Opentrons laboratory. But neighborhoods with many spots do not necessarily correspond to the coronavirus hotspots. The density of spots can often be explained by the presence of a city test center in the area.
On the other hand, neighborhoods with few points are not necessarily free of variants. It just means that few coronavirus samples have reached the laboratory.
There are blind spots across the Bronx, Queens and the southern half of Manhattan. In some postal codes, too few examples have been compiled to draw sound conclusions. On Roosevelt Island, for example, only one case was followed up.
The city on Monday released a separate report based on zip code level data from the Pandemic Response Lab, as well as the city’s own lab. It also showed that the ratio B.1.1.7 and B.1.526 is growing rapidly.
According to the report, B.1.526 cases have been detected in all five districts, but are occurring slightly in the Bronx and parts of Queens. B.1.1.7 cases have also been found nationwide, but are slightly more common in south Brooklyn, eastern Queens and Staten Island.
How is this information useful?
City officials said the maps show widespread versions of the variants, and that it is an important reminder for people not to let their guards down in any area.
“The best way to address this threat is by vaccinating everyone as quickly as possible,” said Dr. Jay Varma, a senior public health adviser in the mayor’s office, said. “The reality is that you run any of these risks, no matter where you are.”
Dr. Chokshi said the geographical breakdown of variants illustrates where the variants were found and how widespread it is across the city, questions that health officials have been asking for weeks.
Monitoring clusters in certain neighborhoods can lead to insights into variants that have so far remained a mystery to health officials.
Because B.1.526 apparently originated locally in New York City, dr. Nash said he would expect it to spread more in areas with high levels of community transmission.
Throughout the pandemic, it tended to be poorer parts of the city, where living conditions are more stressful and work is needed to show up in person. The map largely shows this.
In postal codes where more than 20 per cent of the population live in poverty, between 1 March and 1 April there were about three times as many cases of B.1.526 as B.1.1.7 cases such as B.1.1.7. In postcodes with less poverty, B. 1,526 cases were only twice as many as B.1.1.7.
Conversely, vaccination rates also tend to be lower in neighborhoods that have been hit hard and have had more community transmission during the pandemic. Some of these are due to vaccine, and others due to access issues. The city has tried to address this with targeted vaccination campaigns.
“Scarcity is the enemy of fairness,” said Dr. Tom Frieden, a former city health commissioner.
Not all variants are the same
The abundance of variants detected in the city has created a complicated challenge for health officials.
Some variants – such as those first found in Brazil, P.1 and South Africa, B.1.351, which are now appearing in small numbers in New York – contain a mutation that appears to partially escape the virus antibodies previous infection. The variant that was first found in South Africa apparently also makes vaccination less effective.
The variant first detected in New York, B.1.526, apparently occurs with two forms of mutation.
More than half of the B.1.526 circulating in New York City now contain a mutation similar to that carried by the variants discovered in South Africa and Brazil, according to the New York City Health Department.
According to researchers, a different version of the variant contains a different mutation, which may help bind the virus more strongly to human cells and make it more contagious. However, there is still no real-world evidence that B.1.526 is causing serious infection, or that it is more likely to evade antibodies from previous infections or vaccines, although it is being studied, city officials said.
The P.1 variant, which is associated with an increase in cases in Brazil, was detected about two dozen times in New York City between March 16 and April 1, mainly in Queens. A handful of cases of B.1.351 have been found mostly on Staten Island in recent weeks.
“It’s just a reminder that we are not only connected to each other in the city, but that we are also connected to each other around the world,” said Dr. Nash said, “and what happens there can happen here too if we are not careful.”
Lauren Leatherby contributed research.