Flu finding ups the pressure for free vaccination

PUBLISHED : Saturday, 19 April, 2008, 12:00am
UPDATED : Saturday, 19 April, 2008, 12:00am

Experts cite risk from virus changes

An expert panel has found that changes to the flu viruses circulating this year left children not previously exposed to flu especially vulnerable to infection - a conclusion which adds to the pressure to extend free vaccinations for the young.

Yuen Kwok-yung, the chairman of a government panel investigating the deaths of three children with flu symptoms, urged the Department of Health to consider vaccinating more children against flu.

Thomas Tsang Ho-fai, controller of the Centre for Health Protection, said a committee was studying the feasibility of doing so.

'A decision can be expected soon,' said Dr Tsang.

The government offers free flu vaccinations each winter to babies aged 6 months to 23 months in families on welfare. Other children aged 6 months and upwards with conditions requiring long-term aspirin therapy also receive them if they are public hospital in-patients or their families are on welfare.

Those not eligible for free vaccination must pay at least HK$200 for a shot.

Flu expert Malik Peiris, of the University of Hong Kong's department of microbiology, said the flu viruses circulating had changed from those circulating in the past three years.

Two of the virus strains - H3N2 Brisbane flu and H1N1 Brisbane flu - had first been detected last year in Australia and affected North America and Europe before spreading to Asia, including Hong Kong. Another strain, flu B Yamagata, first detected in Japan 20 years ago, was also circulating.

Even the World Health Organisation had been caught flat-footed by the severity of the Brisbane strains, he said. The vaccine it recommended for this flu season, which began in November, did not offer protection against the Brisbane strains.

The vaccine the WHO recommends for use next winter will protect against them, however.

'Every couple of years, flu viruses undergo some slight change,' Professor Peiris said.

Under-fives may not have had flu before and so would not have any immunity, unlike older children and adults who might have partial immunity from previous exposure, he said.

'This is the issue with influenza. Yes, influenza is a common disease and most of the time it is self-limiting and you recover, but it can cause serious complications.

'It is common but it is not a trivial disease.'

David Hui Shu-cheong, head of respiratory medicine at Chinese University, said the Centre for Health Protection's scientific committee on vaccination would review medical literature on vaccination before making recommendations.

Childhood flu vaccination was the right recommendation, he said, but some child vaccines had caused a rare allergic reaction called Guillain-Barre syndrome, a form of paralysis.

'The committee has to balance the risk and benefits,' he said. Professor Hui sits on another of the centre's committees.

Tim Pang Hung-cheong, of the Society for Community Organisation, said child flu vaccinations should be free or government-subsidised. The group is, among other things, an advocate for patients' rights.

An 11-year-old boy admitted to Prince of Wales Hospital in Sha Tin with flu symptoms is seriously ill with encephalopathy.