"The cases of the B1617.2 variant are rising, they have risen very steeply and much of the media have reported a 160 per cent rise in cases over the week period but they seem to be slightly levelling at the moment".
Ministers have also insisted that they won't "hesitate to put in measures that we think are necessary to try and tackle the transmission of any variants".
"Fortunately we've had a good proportion of the population vaccinated, but there's still people who aren't vaccinated in high-risk groups, the vaccine isn't 100 per cent effective, and also even in the younger groups, if you get many, many thousands or hundreds of thousands of cases, then you will expect a lot of hospitalisations and deaths to result from that".
A double dose of vaccines is nearly as effective against the fast-spreading variant first identified in India as it is against Britain's dominant strain, English health officials said.
PHE said the difference in the effectiveness between the vaccines may be due to the AstraZeneca second dose being rolled out later than the Pfizer vaccine.
Residents have been told not to be "alarmed" at the spread of the latest strain, known as VUI-21MAY-01 or AV.1.
The North West of England has recorded the most number of cases of the variant, with Bolton, Blackburn with Darwen and Bedford among the worst affected.
This variant was previously called the "double mutant" because of two mutations in the virus's spike protein (E484Q and L452R).
U.S. President Joe Biden has banned most travel from India, though the order doesn't apply to U.S. citizens or permanent residents. The CDC has also increased sequencing capacity through contracts with commercial diagnostic laboratories.
India's tech ministry reportedly asked social media companies to remove the term "Indian variant".
The UK is sampling around 50% to 60% of all positive Covid-19 samples, said Moritz Kraemer an epidemiologist at the University of Oxford, which provides crucial detail of the distribution of the B.1.617 variant.
Around one in 1,110 people in private households in England had COVID-19 in the week to 15 May - up from one in 1,340 the previous week.
Scientists are examining a new "triple mutant" Covid variant with a "strange combination" of genes which was discovered in Yorkshire.
More than 37 million people in the United Kingdom have now had their first vaccination, and 22m have had their second.
Thus far, 10.7% of Indians have received at least one dose, and 3% have received both doses.
"It is now clear how important the second dose is to secure the strongest possible protection against Covid-19 and its variants", the health secretary, Matt Hancock, said.