‘Several important lessons’ from Tan Tock Seng Hospital COVID-19 cluster, says Gan Kim Yong Toggle share menu Advertisement ‘Several important lessons’ from Tan Tock Seng Hospital COVID-19 cluster, says Gan Kim Yong Hospital staff walking towards Tan Tock Seng Hospital's Accident and Emergency (A&E) department on Apr 30, 2021. (Photo: Calvin Oh) 11 May 2021 07:24PM) Share this content Bookmark SINGAPORE: Singapore has learnt "several important lessons" from the COVID-19 cluster at Tan Tock Seng Hospital (TTSH), among them - that the B16172 strain “appears very infectious” and vaccines are “not a guarantee” against infection, said Minister for Health Gan Kim Yong on Tuesday (May 11).