OTTAWA, Aug. 17 (Xinhua) -- A Canadian scientist has warned of the dangers of rushed and massive vaccination to deal with the A/H1N1 flu, saying the tests may not provide long-term safety data, media reports said Monday.

    As infectious experts predict the northern hemisphere could face a "second wave" of A/H1N1, vaccine manufacturers have begun testing the first batches of the vaccines, with volunteers rolling up their sleeves to try the new formulations for safety and effectiveness. They will be testing different dosages, looking to see if any trigger immune reactions or other possible side effects.

    But University of Manitoba medical ethicist Dr. Arthur Schafer is worried that the first scientific data will only provide information on the correct dosage and immediate reactions from the shot. Long-term safety data will not be available when vaccination programs begin in the fall.

    "We're rushing the vaccines, and there isn't time for them to be properly tested for effectiveness. There won't be time for them to be properly tested for safety," he said in a recent interview.

    The World Health Organization has acknowledged safety issues "will inevitably arise during a pandemic when vaccine is administered on a massive scale. For example, adverse events too rare to show up even in a large clinical trial may become apparent when very large numbers of people receive a pandemic vaccine."

    Schafer said he has had a lot of feedback from scientists around Canada who have emailed or phoned to say they shared his concerns.

    Shafer said the evidence from the southern hemisphere suggests the A/H1N1 flu is no more lethal than the seasonal flu. So he wonders why a mass vaccination program is being considered.

    "There are serious public health issues and issues of ethics as to whether we should be distributing (vaccines) massively to healthy people, including children and pregnant women, when there are really big question marks about their effectiveness and their safety."

    But other scientists have said speeding the vaccine through production and testing is necessary.

    Toronto vaccine specialist Dr. Allison McGeer says as the safety data comes in and a clearer picture of the flu's effects in the southern hemisphere emerges, it will be easier to decide who needs it.

    She points out that there are risks to any influenza, including the A/H1N1 flu. The vaccine is designed to protect those at risk.

Special Report:  World Tackles A/H1N1 Flu