The number of new cases of A/H1N1 swine flu in England rose again last week, but the second wave of the pandemic continues to be gradual, figures from the U.K.'s Department of Health showed Thursday.

The Health Protection Agency estimated there were 78,000 new cases of the virus in England last week, up from 53,000 the previous week and 27,000 the week before that, said Liam Donaldson, England's chief medical officer. The estimated cumulative number of cases now stands at 521,000, he said.

Although the number of new cases remains below the weekly peak of 110,000 seen in the first wave in July, the number of deaths attributed to swine flu in the U.K. has risen to 137 - 97 in England, 25 in Scotland, eight in Northern Ireland, and seven in Wales.

Donaldson said although the disease was mild in most cases, he remained concerned about the increasing number of patients that required critical care. The number of patients in hospital as of Wednesday was 751, including 157 in critical care.

But he said he hoped the U.K.'s vaccination program launched last week would help limit future infections. Officials said the U.K. had received 5 million doses of GlaxoSmithKline PLC's (GSK) Pandemrix vaccine and 1 million doses of Baxter International Inc.'s (BAX) Celvapan vaccine.

-By Nicholas Winning, Dow Jones Newswires, +44 207 842 9498; nick.winning@dowjones.com