The Department of Health said BioNTech shots should be used within 31 days of thawing, in accordance with the manufacturer’s instructions.
But on January 2 and January 4, the New Town Integrated Medical Centre in Kingswood Richly Plaza, Tin Shui Wai administered doses that had thawed up to 33 days beforehand, officials said.
Two people who received the expired doses ended up in hospital after reporting stomach discomfort, with one recovering after going to accident and emergency, and the other still in hospital under observation and in a stable condition.
Health officials said the distributor of the vaccine says there is no information to show that receiving it after the use-by date can cause an adverse reaction.
“We have requested the medical centre to follow up on the conditions of the 36 members of public, and [we have] consulted with local experts and the preliminary assessment is that the vaccination is still effective,” said Chuang Shuk-kwan of the Centre for Health Protection.
But Chuang said that as a prudent measure, those affected by the blunder should have their antibody levels checked.