HONG KONG: What's wrong with swine flu vaccines if more than half of doctors and nurses in Hong Kong have told surveyors that they don't want to receive flu shots? The question is complicated by fears of rare side effects such as Guillain Barre Syndrome (GBS).

But that's not the only objection. With alternative medicines gaining traction among the public, many are starting to question the practice of using vaccines as defenses against diseases in general.

Some relate vaccines to autism, an increasingly prevalent condition for which modern medicine cannot account. Interestingly, autism is not found among children of the Amish faith, who do not take vaccines.

It's believed children under the age of two are especially vulnerable to vaccines, because their blood-brain barrier is not fully developed. Vaccines may cause brain infections, whose symptoms are labelled autism.

But the causality between vaccines and autism is considered "unestablished".

"There have been concerns that vaccines might be associated with autism, in particular measles, mumps and rubella (MMR) vaccine. Many studies have looked at whether there is a relationship between vaccines and autism. To date the studies continue to show that vaccines are not associated with autism," said a Department of Health (DOH) spokesperson.

The World Health Organization (WHO) has concluded no evidence exists linking MMR vaccine and autism.

There also are concerns over the use of additives. Thimerosal, a mercury compound, is used in some vaccines as a preservative. Aluminum and squalene are used as adjuvants, to stimulate the immune response to vaccine antigens.

But there is no evidence the use of these should be a safety concern. The risk factors are unproven and the WHO has deemed it unnecessary to order pharmaceutical companies to change their practices, said the DOH spokesperson.

To parents like Miranda So, who has a 9-year-old son, "unestablished causality" is not good enough to allay her fears.

"What is unestablished causality? In terms of medical research, it means only that there has been no research to date that proves the presence of risk. But it's difficult to prove something medically. You can't do experiments on human beings," she said.

Her son has received some 20 kinds of vaccines since birth. "I just don't like the situation: a little bit of virus is injected into my son's body every year. Who knows what kind of harm is being done?" So asked.

Albert Lee, professor of Public Health and Primary Care of the Chinese University of Hong Kong (CUHK), said he understands the anxiety toward the continual increase in the varieties of vaccines given to people but a better alternative is yet to be found.

"The fact is there are more and more viruses," he said.

Medical decisions are often a matter of weighing the benefits and risks, Lee said. "In the long run, the benefits of vaccination are much greater than the risks," he maintains.

This brings up another issue: professional resistance to the swine flu vaccines.

According to CUHK, which has conducted several surveys on Hong Kong medical professionals' attitude toward swine flu vaccines, a primary concern is the effectiveness of the newly-developed vaccines.

A Surveillance System for Monitoring Adverse Events Following Influenza Vaccination, an article printed in the Hong Kong Center for Health Protection's (CHP) periodical Communicable Disease Watch, cited WHO data concerning the effectiveness of vaccines. The data showed that "the use of seasonal influenza could reduce influenza by 59 percent in healthy children aged two to 15 years and 50-80 percent in healthy individuals aged 16 to 65 years."

If well-developed seasonal flu vaccines can offer 50-80 percent protection, how effective are swine flu shots?

The DOH spokesperson said the swine flu vaccines are expected to give at least the same amount of protection as seasonal influenza vaccine or better.

Seasonal flu shots contain vaccines against three strains of the influenza virus. They are chosen by the WHO Global Influenza Surveillance Network because they're deemed "most likely" to make people ill in the coming flu season. In other words, the vaccines are results of an educated guess.

But the swine flu vaccines are an exact match to the strain of influenza virus that is currently circulating, said the DOH spokesperson.

Skepticism toward the newly-developed vaccines is natural, said Lee. "It's human nature to be cautious about new things. In this aspect, medical professionals are no different than ordinary people," he observed.

Alfred Tam, a pediatrics specialist, said he's careful about recommending vaccines to patients. "Personally, I would suggest swine flu shots," he added.

The influenza obviously has spread fast and it's hard to estimate the impact of the second wave, he said.

"Children are particularly susceptible to respiratory infection. Many of them don't know how to protect themselves or others when they cough and have phlegm. Unless they are unsuitable for flu shots because of conditions such as allergies to antibiotics, I think children should receive swine flu shots," he said.

(HK Edition 11/03/2009 page1)