SINGAPORE - People should not overreact to cases of vaccinated individuals getting infected with Covid-19, and make the "biggest mistake" of thinking there is no need for vaccinations as they do not work, said Education Minister Lawrence Wong.
"That would be disastrous because the vaccinations do work," he stressed, noting that they protect people from the risk of severe disease and help reduce transmission.
While vaccines are not foolproof, they will have a bigger impact on reducing the overall virus spread in the community when more people are vaccinated, he said, urging every person who is medically eligible to get inoculated.
Mr Wong's remarks at a press conference on Friday (April 30) came after it emerged that four of the five Covid-19 cases who are medical staff working at Tan Tock Seng Hospital (TTSH) have been vaccinated against the coronavirus.
The five staff include two doctors, a nurse, one healthcare assistant, and one cleaner who had worked in the ward where this cluster of cases had emerged.
Of the eight hospital patients in the 13-person cluster, one person had received both doses of the vaccine, while another got one dose. Seven of the eight patients were admitted to Ward 9D, while one was admitted to Ward 9C.
The Health Ministry's director of medical services, Associate Professor Kenneth Mak said those who have been vaccinated have derived some level of immunity.
"But as illustrated by this cluster, vaccination doesn't provide 100 per cent protection, but it increases your resistance to getting symptomatic infection, it reduces the risk of you getting an infection and spreading that," he added.
The vaccinations remain protective for the wide majority of the population and staff who had received them, Prof Mak added.
He said investigations are ongoing to ensure that the Covid-19 cases in the TTSH cluster were properly vaccinated.
So far, no issues associated with vaccine quality or the cold chain supply of vaccines at the vaccination centres have been found.
Describing the cases of vaccinated individuals getting Covid-19 as "breakthrough infections", Mr Wong said the fact that this can happen is "something we already knew about".
"So we should not overreact to the news of breakthrough infections, or worse, make the biggest mistake, which is to say that, 'Oh, vaccinations don't work, and therefore, maybe there is no need for a vaccine'," he added.
The National Centre for Infectious Diseases (NCID) is also testing all cases that have been admitted there to determine their Covid-19 status.
These patients may have been admitted and transferred to NCID because of a positive polymerase chain reaction (PCR) test, which may mean an active infection or patients who have been previously infected and are persistent viral shedders.
The hospitals are also performing phylogenetic tests to assess whether any of these infections are due to viral variants of concern, Prof Mak said.
The genome of the virus is first sequenced before a phylogenetic analysis is done on it, which allows for cases to be linked to clusters and variants of concerns to be identified.
Numerous variants have been detected globally, such as Britain's B117 strain, Brazilian P1 variant, South Africa's B1351 and India's "double-mutant" variant called B1617.
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