August 1, 2022

Those who had Covid-19 4 to 7 months ago have much lower chance of infection compared with the uninfected

By brit

SINGAPORE – People who had Covid-19 four to seven months ago have a much lower chance of catching the virus now, as compared with someone who has never had Covid-19 before, Health Minister Ong Ye Kung said on Monday (Aug 1).

For instance, he said that for those infected four to seven months ago, the probability of getting infected again is just 3 per cent that of a person who has never had Covid-19.

But this rises to 20 per cent in those infected with the Delta variant last year.

Responding in Parliament to a question by Ms Joan Pereira (Tanjong Pagar GRC), who had asked about reinfection rates in the light of the new Omicron sub-variants, Mr Ong said that for those infected over the last three months, the chance of getting another infection is “very rare”.

“Of course, this picture will change as time goes by, and the protective effect of prior infections will wane. Hence, having been infected by Covid-19 before should not be a reason to let your guard down,” said Mr Ong.

He added that reinfection during the current wave has been low in Singapore, likely due to the good vaccination coverage here and the nation having gone through a major Omicron BA.2 infection wave recently.

Mr Ong said that reinfections are likely to increase as the protection from prior infections wanes. He added that the Ministry of Health (MOH) should start to include reinfection numbers in its daily case counts.

In the past, if a patient was infected twice, he would be counted only once in the daily reports, said Mr Ong.

From today, MOH will start to report the number of infection episodes rather than the number of daily infections, which should lead to a more accurate reflection of the pandemic situation, he said.

Mr Ong said that after 10 months, the protective effect of three doses of mRNA vaccines remains very strong in preventing severe illness. This is why the Government is recommending those aged 80 and above to get their second booster, so as to protect themselves against severe disease.

Mr Ong said that those aged 50 to 79 have a strong protection level from their previous three shots, but noted that they are at the age when chronic illnesses start to set in. So they will be offered the second booster if they want to take it because they are travelling, or are worried about their health because of underlying illnesses.

He added that experts are actively studying the benefits of a fourth shot for the 60- to 79-year-olds in further reducing the likelihood of severe illness, and that their recommendations will be announced shortly.

Those below the age of 60 do not require a second booster if they are healthy, added Mr Ong.

Responding to a question from Mr Leon Perera (Aljunied GRC) on the effectiveness of non-mRNA vaccines, Mr Ong said that while Novavax’s vaccine has been shown to be effective in preventing severe illness, data from around the world has shown that those from Sinovac and Sinopharm are slightly less effective.

“Having said that, they do have a protective effect. Having those (vaccines) is better than not having vaccination,” he said.