Covid-19 cases in the U.K. fell for the seventh day in a row on Tuesday to 23,511 from 46,588 a week prior, but Prime Minister Boris Johnson has urged the public to remain cautious.

Speaking to LBC radio on Wednesday, Johnson said it was important to avoid jumping to conclusions and remember that "the virus is still out there."

"A lot of people have got it and it still presents a significant risk," he added.

Despite the falling infection rates, deaths within 28 days of a positive test hit 131 on Tuesday, the highest number since March, while hospitalizations have also continued to rise.

Public Health England has pointed to these figures to illustrate that the pandemic is "not over yet," and Yvonne Doyle, medical director at Public Health England, suggested that the death and hospitalization figures are the result of the spike seen in recent weeks, as the delta variant spread rapidly.

In a note Tuesday, U.S. research firm Fundstrat highlighted that the U.K.'s delta surge peaked after around 45 days, similar to the 50-day mark seen in India, where the strain was first detected.

JPMorgan analysts on Wednesday altered their previous projections for the effective reproduction number of the virus to rise from 1.3 on July 19 to 1.6, a level that would have seen infections doubling every 10 days and reaching 400,000 in the U.K. within a matter of weeks. Health Secretary Sajid Javid had warned that infections could top the 100,000 per day mark within weeks.