The vaccines for swine flu manufactured in Japan are safe, but doctors should administer them carefully to patients with severe chronic diseases, a health ministry committee said.

As of Nov. 19, out of the roughly 4.5 million people who have been vaccinated, only 68 cases of serious side effects were recorded, according to a health ministry survey.

The 68 cases included 13 deaths.

The frequency of cases of severe side effects detected in the administration of vaccines for the new H1N1 virus was higher than for seasonal flu vaccines, they said.