GlaxoSmithKline, a pharmaceutical company that manufactures H1N1 vaccination, has requested that Canadian medical centers not use one batch of the immunizations.

Spokesperson for GlaxoSmithKine state that this batch has caused six serious allergic reactions; this is greater than expected. The recalled batch contained approximately 172,000 doses (a total of 7.5 million doses have been distributed in Canada) and was shipped out last month.

No other countries have been affected by this recall.