A new study has concluded that children suffering from respiratory diseases are at a heavy risk of developing swine flu.

The research lead by David G. Nichols, MD, professor of anesthesiology/critical care medicine and pediatrics at the Johns Hopkins University School of Medicine, analyzed 13 children already suffering from swine flu, who were admitted to Johns Hopkins Hospital Children's Center pediatric intensive care unit, last year.

The researchers found that 92% of them had a lung disease before getting down with the flu.

"Critical H1N1 disease in children has different and rapidly changing manifestations in the patients' lungs," explained Dr. Nichols.

Another concern raised by the team was that these children, who are suffering chronic diseases, are also prone to type-2 pneumonia.

Shu Yuelong, Director of the Chinese National Influenza Center, said that another H1N1 outbreak is likely to occur this winter.

In view of the intense cases of flu deaths reported in December, last year, the health experts are urging the vaccination of those who fall in the high-risk group, against the flu. The group comprises pregnant women, patients of chronic ailments and obese people, in particular.