Mortality Rate and Serious Complications amongst Singaporeans who Suffer COVID-19 Reinfections

1 Mr Yip Hon Weng asked the Minister for Health in light of the US research paper suggesting that COVID-19 reinfection is more dangerous (a) what is the mortality rate and serious complication rate of those in Singapore catching COVID-19 for a second or third time vis-a-vis a first-time infection; and (b) how does vaccination alter the mortality and severe illness rate in both groups.

The Minister for Health (Mr Ong Ye Kung): Sir, the Member has referred to a US research paper, which according to media reports, found that second COVID-19 infections are more severe compared to first infections.

I am afraid the media reports have not been clear or accurate. The paper cited by the Member does not compare the severity between first-time infections and reinfections. Instead, it compares the outcomes of those who had a first COVID-19 infection, versus those with two or more infections. And therefore, not surprisingly, the study found it is more likely for persons to develop adverse health outcomes after two or more episodes of COVID-19 infection, compared to people who had only one infection episode. Put it simply: getting sick twice is worse than getting sick once; but getting sick for the second time is not worse than getting sick the first time.

In fact, from September to mid-November 2022, the mortality rate of reinfection cases in Singapore was four per 100,000 cases, lower than that for first-time infection cases at 35 per 100,000 cases. The rate of severe illness – those requiring oxygen supplementation, intensive care or death – was also lower for reinfections at 232 per 100,000 cases, compared to first-time infections at 282 per 100,000 cases.

Our data also shows that achieving minimum vaccination protection – in other words, three doses of mRNA or four doses of Sinovac – lowers the risk of severe illness, whether it is a first infection or re-infection.

Mr Speaker: Mr Yip.

Mr Yip Hon Weng (Yio Chu Kang): I thank the Minister for his clarification. Is there any data that the bivalent vaccine booster has helped to reduce severe illness and death? What is the uptake of the bivalent vaccine? And with the Singapore public treating living with COVID as a new normal, how can we improve the uptake of the bivalent vaccine?

Mr Ong Ye Kung: The initial data from clinical trials of the bivalent vaccine and now, empirical data based on our actual lived experience, show that it has been effective in reducing severe illnesses. Today, when you compare, especially for the aged, those who have gotten full protection and up-to-date vaccination, versus those who have not, it still shows a significant difference between the prevalence of severe illness if they get infected. I do not have the data with me, but it is at least four to five times more likely to fall severely ill if you are not fully vaccinated or not update-to-date with the vaccination.

Today, we are administering healthy numbers of vaccines – about 20,000 a day in uptake; it is quite good. This includes both mono-valent and bivalent. I do not have the breakdown, but the take-up has been encouraging for people keeping their vaccination up-to-date. We will continue to put out public messages to encourage people to take their vaccine, keep it up-to-date, because the pandemic is not over. We will be stepping up our mobile vaccination teams into the heartlands so that, especially for the seniors, they will find that it is more accessible to getting their vaccination up-to-date with the mobile vaccination teams in place.

Mr Speaker: Mr Gan Thiam Poh.

Mr Gan Thiam Poh (Ang Mo Kio): Thank you, Speaker. I just want to ask the Minister is there data to show what is the reinfection rate and the seriousness of using mRNA and other vaccines.

Mr Ong Ye Kung: Can the Member repeat that? I was not too clear.

Mr Gan Thiam Poh: My question is, is there data to show what is the effective rates of using mRNA and the seriousness of reinfection, and the difference between mRNA vaccine and others, these two categories.

Mr Ong Ye Kung: There was a similar Parliamentary Question before and I showed some of the data. The Member should be able to find it in the Hansard. Essentially, for the non-mRNA vaccine, we mostly use Sinovac. Sinovac is effective if you take three or more shots, preferably four shots. It does protect you against severe illness. I remember the protection rate is about 70-plus percent. But if you use mRNA, it is even more effective, at 80-plus, almost 90%.

So, both are effective, with mRNA vaccines having an edge over Sinovac.