The Delta variant, first detected in India, constituted over 6 per cent of COVID-19 cases tested for virus variants in New York City, according to official data from the city's health department.

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The New York City Health Department said in its recent update that out of the 105 NYC COVID-19 cases tested for variant viruses for the week ending June 5, the Delta variant (B.1.617.2) constituted 6.7 per cent. "Currently, B.1.1.7 (Alpha) and B.1.526 (Iota) are the most widespread variants in the city. We are also closely monitoring P.1 (Gamma) and B.1.617.2 (Delta), which have been spreading rapidly in the US and other countries,' the NYC health department said. The Alpha variant constituted 36.2 per cent (38 cases) of the 105 NYC COVID-19 cases tested for variant viruses for the week ending June 5, while the Iota variant was found in 4.8 per cent cases (5) and Gamma in 17.1 per cent cases (18). The number of COVID-19 cases with Delta variant was seven.

The update further said that in the last four weeks, the Delta variant has been observed in 5.6 per cent of the tested cases. New York City Mayor, said on  17 June that the daily number of people admitted to New York City hospitals for suspected COVID-19 stood at 68, confirmed positivity is 8.22 per cent, hospitalisation rate 0.42 per 100,000.

"New reported cases on a seven-day average, today's report 186 cases. Percentage of people testing city-wide positive for COVID-19, today's report seven-day rolling average 0.57 per cent", he said. As of June 17, the total number of tests performed in New York City stood at 12,336 and the cumulative number of COVID19 tests performed stood at 5,884,069. According to the COVID-19 cumulative data in New York City since the city's first confirmed case was diagnosed on February 29, 2020, the number of confirmed cases stood at 785,822 and probable cases stood at 167,254 and total deaths were 33,370, including 28,282 confirmed COVID-19 deaths and 5,088 probable deaths where the cause of death was listed as COVID-19 or similar.

So far, 54.1 per cent of New York City residents have been vaccinated with at least one dose and 47.8 per cent are fully vaccinated. The World Health Organisation (WHO) said that the Delta variant is becoming the dominant variant globally because of its significantly increased transmissibility. "The whole situation is so dynamic because of the variants that are now circulating and the Delta variant is well on its way to becoming the dominant variant globally because of its significantly increased transmissibility," World Health Organisation Chief Scientist Soumya Swaminathan said responding to a question at a press briefing on Friday.

According to the COVID-19 Weekly Epidemiological Update issued by the WHO on June 15, the Delta variant is now being reported in about 80 countries around the world. Another 12 countries and areas are "reporting the detection of B.1.617 without further specification of lineage at this time". The B.1.617.2 Delta variant was first detected in India around October 2020. Swaminathan said there is a need for more data from well-designed studies on the efficacy of the different vaccines that are in use in different countries against the different variants. She added that there has to be in place a study that uses a good design, or a randomised trial or studies during the rollout of a vaccine in a country to see what happens when people have one dose of the vaccine or two doses of the vaccine and see how many are getting infected and are ending up hospitalised and getting seriously ill.

"This is something that we are watching very carefully and documenting and we now have a special expert group that's been set up to exactly track the performance of vaccines and their effectiveness when used at the population level in relation to the variants. This also means that countries need to do sequencing, side by side with documenting vaccine effectiveness. We need to expand sequencing," Swaminathan said, adding that through this information, experts can start getting some solid evidence on vaccine performance.