Flu vaccines have been at least 50 percent effective in the winter flu season, the Centre for Health Protection said yesterday.
The government will look into the feasibility of ordering flu vaccines from the southern hemisphere amid a citywide shortage.
The Scientific Committee on Vaccine Preventable Diseases under the Department of Health held a meeting yesterday regarding the supply of vaccines.
Speaking after the meeting, chairman of the committee Chow Chun-bong said the latest figures collected from private clinics showed that the flu vaccines have been 40 percent effective this season, whereas the effectiveness in preventing influenza-associated hospitalization among children has been over 60 percent.
"The overall effectiveness is over 50 percent. Vaccination is still the most effective measure in preventing flu infection," Chow said.
The center said it had procured 460,000 vaccines ahead of the winter flu season, and purchased 44,000 extra shots in the past three weeks. There will be 24,000 more shots arriving in Hong Kong by the end of March.
As many private doctors have expressed concern over the shortage of vaccines, Chow said the government will also attempt to order flu shots from the southern hemisphere, which have "very similar effectiveness" compared to the shots Hong Kong has been using from the northern hemisphere.
But only one shot a year is needed, he said.
University of Hong Kong microbiologist Yuen Kwok-yung had earlier predicted an influenza A outbreak following a type B epidemic.
Chow said if influenza A emerges, it could be the H1 virus or H3 virus.
"H3 would be a headache as Australian data show that the current vaccine is only 10 percent effective," he said. "But we should still get vaccinated if that's the case because 10 percent is still better than nothing."
The department has yet to decide about the amount of vaccine they will order. If they can get hold of the southern hemisphere's vaccine, it could arrive in April.
Separately, the center announced a flu outbreak at a secondary school in Ho Man Tin yesterday.
The outbreak involves 18 students -- 14 boys and four girls - aged between 12 and 19, and three staff members.
Nineteen of them have sought medical attention and one was discharged after being hospitalized. Two students tested positive for influenza B.
According to the Hospital Authority, 5,772 people sought emergency treatment on Sunday, 1,021 of whom had to be admitted to wards.