The swine flu has contributed to 37 deaths in Canada over the past five days, bringing the total number of fatalities blamed on the A(H1N1) virus to 198, a senior health official said Tuesday.

So far, 20 percent of the population has been vaccinated against the virus in the largest immunization program in Canadian history, Chief Public Health Officer David Butler-Jones told a press conference.

Thirty-six out of 6.6 million people who received the flu shot reported serious adverse reactions to the vaccine in Canada - mostly anaphylactic reactions or convulsions brought on by fever, Butler-Jones said.

One person also died after being immunized, he said.

The swine flu has so far contributed to more than 1,600 hospitalizations in Canada since April and at least 300 critical care ward admissions, according to Health Canada.