The manufacturer of a H1N1 vaccine that caused severe adverse effects in Canada last month will not bear any responsibility if similar complications occur in Vietnam, the World Health Organization (WHO) has said.

But the WHO statement admitted that concerns had been on the rise after reports of severe adverse effects following Arepanrix immunizations in Canada on November 24.

The Canadian Public Health Agency confirmed early this month seven cases of anaphylaxis, a severe allergic reaction that is rapid in onset and may cause death, following immunization with a certain batch of Arepanrix vaccine produced by the British-owned GlaxoSmithKline. Canadian authorities also withdrew around 172,000 doses of the vaccines.

The frequency of anaphylaxis following immunization with vaccines from the lot was four per 100,000 doses distributed, which is higher when compared to the usual 0.1-1 per 100,000 doses, the WHO statement confirmed Wednesday.

Decision about the share of WHO sponsored vaccines each of the 95 eligible low and middle income countries would receive was based on assessments conducted in October this year, before the withdrawal of the batch of vaccine in Canada, said Dr. Jean-Marc Olivé, the WHO country representative in Vietnam.

Besides the lot that caused higher-than-usual incidence of anaphylaxis in Canada, Olivé said approximately 15 million doses of Arepanrix had been distributed in Canada and, overall, the frequency of adverse allergic reactions following immunization is less than one event per 100,000 doses. This rate does not exceed the rates typically reported for other vaccines.

He said all receiving countries of the vaccine would have to commit not to complain if any severe adverse affects take place.

The technology to produce the vaccines had been long established and any post-inoculation consequences would not stem only from the vaccine itself, according to Olivé. There is thus no reason to blame the vaccine provider for this, he said.

Cautious

Nguyen Thi Kim Tien, Deputy Health Minister was quoted by Tuoi Tre newspaper on December 10 as saying that some of the complications in Canada had already resulted in fatality.

But in a statement sent to Thanh Nien Weekly dated December 8, the WHO said there had not been deaths conclusively linked to the vaccine in any country.

The WHO did not immediately response to the latest Thanh Nien Weekly interview request seeking clarification before this story was printed.

The administration of a new vaccine in Vietnam should be carried out on a trial basis before the official inoculation is launched, Tien said. The safety and efficiency of the vaccination must be made the leading priority, she added.

Reported by Thanh Nien staff