Mild asthma raises the risk of being hospitalized with more severe H1N1 flu according to researchers in Toronto.

Doctors from the Hospital for Sick Children reviewed the charts of 58 children admitted with H1N1 pandemic between May 8 and July 22.

These children were then compared to 200 others who were hospitalized with seasonal flu during the five flu seasons previously.

The children who were admitted with H1N1 flu were more likely to have asthma than the ones who were hospitalized with seasonal influenza.

46 or 79 percent of the overall children that were hospitalized with H1N1 had a medical condition like asthma, chronic lung disease or heart disease.

The rest of the 12 were previously healthy and five of them were under 2 years of age.

The children suffering from H1N1 did not die but one died among the children who were admitted in the hospital due to normal flu.

He stressed the importance of vaccinations to prevent children from getting sick with H1N1. WHO officials said this week that H1N1 vaccines appear to be as safe as seasonal flu shots.

80 million doses have been distributed globally and at least 65 million doses have already been administered, as per the figures from 16 countries.

The results are based on different vaccines being used around the world, including adjuvanted and non-adjuvanted vaccines, the types being used in Canada.

He said that the best strategy is prevention and the study underscores the importance of vaccination.