New York City health officials said on Monday that infections with the coronavirus variant that first emerged in Britain, B.1.1.7, have been increasing in every borough, but slightly more in southern Brooklyn, eastern Queens, and Staten Island. Genetic analysis shows that B.1.1.7 now accounts for about 30 percent of cases sequenced citywide.
The data, which was included in new maps and a report released by the city, represents the first time officials have offered a ZIP-code level look at how worrisome variants have been spreading in New York, overtaking original versions of virus and clustering in some parts of the city more than others.
The report and maps, which were published Monday afternoon on the city’s health department website, also show that a variant first emerged in New York City, B.1.526, has been increasing at even a faster clip, and now represents some 45 percent of cases genetically sequenced in the city. The maps released Monday show that while B.1.526 is found in all five boroughs, it is slightly more common in the Bronx and parts of Queens.
Overall, more than 70 percent of genetically sequenced coronavirus cases now circulating in the city represent worrisome variants. The data, which spans January 1 to March 27, represents less than 5 percent of all positive test results in the city, as sequencing capabilities remain limited. As a result, it only provides a glimpse of the full picture of how the variants are impacting each community.
New York City has remained at a high plateau of coronavirus cases since February, with some 3,000 to 4,000 new cases reported per day, according to city data. The spread of these variants is likely a key reason that cases have not fallen more even as vaccinations rise, the city’s health department said in the report.
Hospitalizations have been falling, but very gradually, as the most vulnerable get vaccinated. Deaths have also been declining, but at a slower than desired pace, and have been averaging about 50 per day.
The United States has seen an exponential rise of B.1.1.7, which is now the most dominant variant across the country, according to the Centers for Disease Control and Prevention. That variant is about 60 percent more contagious and 67 percent more deadly than the original form of the coronavirus, according to the most recent estimates.
It has slammed Europe and helped fuel the worst-in-the-nation outbreak in Michigan. Until recently, the variant’s rise in the United States was somewhat camouflaged by falling infection rates overall, leading some political leaders to relax restrictions on indoor dining, social distancing and other measures. The C.D.C.’s efforts to track down the variants have greatly improved in recent weeks and will continue to grow, though Britain, which has a more centralized health care system, began a highly promoted sequencing program last year that allowed it to track the spread of the B.1.1.7 variant.
Vaccines do appear to be effective against the variant.
Less is known about the B.1.526 variant, which was first documented by researchers in the Upper Manhattan area of New York City last November and has since spread widely through the city and beyond. City officials have said that the variant may be more transmissible, and is outpacing even B.1.1.7 in some neighborhoods.
But it is still unknown whether the variant has an impact on disease severity, re-infection, or vaccine effectiveness. The city said it has no evidence that it does, but that it is studying those possibilities.
The city also warned on Monday that the P.1 variant, which was first identified in Brazil, is increasing its presence, though its incidence as a percentage of total cases remains very low.
The city did not release data or a map showing where P.1 cases have been identified. It has previously said that the variant accounted for 1.3 percent of sequenced samples as of late March — just 24 total cases of P.1. The variant maps released on Monday also excluded all ZIP codes where the total number of sequenced cases was fewer than three.
P.1 is also more transmissible than original versions of the virus, and there is some evidence of immunity evasion among both people who previously had Covid-19 and fully vaccinated people. It is spreading widely in South America and has appeared in many states.
The city’s report did not mention the B.1.351 variant, first found in South Africa, which can partially dodge the body’s immune system response. The city had previously reported sequencing 6 total cases of B.1.351.