A Tale of Two Cities

And just like that, we are now into March 2022. Quite a few things happened in February 2022.

A little known fact is sometime in late February (around 27 Feb 22), we crossed the fateful number of 1000 Covid-19 deaths in Singapore, some 25 months after the first case landed here. This hobbit suspects that we are now at the peak or near the peak of the Omicron wave. We are now chalking up 15,000 to 26,000 cases a day and daily deaths number from the teens to the twenties. Based on these rough numbers, the case fatality rates of Omicron can be estimated to be about 0.1% in Singapore, approximating that of the seasonal flu. There are two caveats to this number of 0.1%:

• fatalities usually lag behind case number by two to four weeks, we could yet see a rise in fatalities in the coming weeks
• the number of cases is probably an underestimate as many cases now go unreported under Protocol 2: the infected self-test and stay at home for 3 to 7 days without being captured by official data collection methods.

The number of ICU cases have also remained relatively stable, in the range of 40 to 50 cases a day. We have about 350 to 400 ICU beds in the system and the strain imposed on ICU beds by Covid-19 patients is largely bearable. The real issue is at the primary care and A&E level where doctors are swarmed by many patients, many of which have no or mild symptoms.

Meanwhile in Hong Kong (HK), a city that Singapore is often compared with for anything ranging from property prices to wanton noodles, the situation is getting grimmer by the day.

On 2 March 2022, HK has already chalked up 1168 deaths¹, surpassing that of Singapore (1030 deaths as of 1 Mar 2022)². This in itself is not surprising because HK has a larger population than Singapore. But the momentum of this current wave is just simply all-consuming. Up till 2 March, HK logged a very respectable total of 293,730 cases, but just for the last four days (27 Feb, 28 Feb, 1 Mar and 2 Mar) the case numbers were 26,026; 34,466, 32,597 and 55,353 respectively, making a total of 93,090 cases. The daily deaths in the last three days were 83, 87, 117 and 116, making a total of 403 cases. In other words, 34.5% of Covid-19 deaths and 39% of Covid-19 cases occurred in the last four days. If that isn’t frightening, I don’t know what is.

It is interesting to note that Singapore has 748,504 cases as of 1 March, about three times that of HK, but the number of deaths are about the same in both places. In other words, ignoring the underdiagnosing of cases in both places, the case fatality rate in HK is three times that of Singapore.

One reason to explain the difference could be that in 2020, large numbers of young healthy foreign workers were infected in Singapore. Very few of them died and this would lead to a lower overall case-fatality rate in Singapore. But this cannot explain the difference entirely.

Another reason could be that it is a well-known fact that when hospital systems are overwhelmed, fatality rates increase. That could be happening in HK now, and that is why we see mainland China rushing in resources to help HK cope.

The other very important factor is that vaccination rates in HK are pretty low among the elderly. About 77% of those eligible have received at least two doses of vaccination. A good number, but not as high as the corresponding figure of 94% for Singapore.

What is really problematic is that it is estimated that at least 40% of those 70 and older have NOT received two vaccination doses. In other words, the folks who are the most vulnerable, who need vaccination most are also the people least likely to have received any or adequate vaccination. Only 30% of those above 80 have received 2 doses and 59% of those aged between 70 and 79 have received 2 doses. The corresponding numbers for Singapore for these two age groups are 94% and 96% respectively

This has been a walking timebomb ever since vaccination was offered in early 2021 in HK. And now this timebomb has exploded.

The principles of communicable disease control remain the same even as pathogens change. These principles are destroying the source of pathogen, breaking transmission, treating and isolating the infected and protecting the susceptible, i.e. vaccination. Breaking transmission such as social distancing, wearing of masks etc worked well in the early phases of the pandemic because the original Covid-19 virus was not as transmissible as the later variants. The basic reproduction number R₀ was estimated to be about 2.7 for the original variant. That number increased to 5 for the Delta variant. For the Omicron, it is estimated to be at least 7. In other words, one Omicron patient is estimated to infect at least 7 other persons.

For perspective, the R₀ for seasonal flu is 1.2; for smallpox it was 3; polio: 4 to 6. Very infectious diseases such as mumps and chickenpox will have a R₀ of 10 to 12 and measles 12 to 18. Another way to look at it is the doubling time. The doubling time for the original variant is about 7 days, while for Omicron, it is down to 2 to 3 days.

The doubling time and R₀ numbers for Omicron suggest that it is far more infectious than the original variant of early 2020 or even Delta. What that means is that the old strategy of breaking transmission by wearing masks, handwashing and social distancing etc will become more and more ineffective in stopping Omicron vis a vis older variants.

Another way to look at it is that in order for transmission to be effectively broken, the costs of doing so will become more and more prohibitive for Omicron when compared to earlier variants, i.e. with a R₀ of 7 compared to 2.7, one would need more and more draconian policies and measures to be put in place to break transmission.

But this need not be so if a higher vaccination rate is achieved. While it is true that higher vaccination rates do not prevent infections in many cases with the current Omicron wave, the truth is it does reduce the number of infections significantly. And it certainly dramatically reduces the number of seriously ill or ICU cases. Because of our high vaccination rates among all age groups including the elderly, this hobbit will wager that Singapore is not going to see 100 deaths a day in this round of pandemic with the Omicron variant. It is also very unlikely that we will reach 50,000 cases a day, but this hobbit won’t rule that out completely for now.

So to all those anti-vaxxers out there who still insist vaccination is a bad thing, just observe what is going on in Hong Kong now. They already have a high vaccination rate, but they are still being hit badly now. The vaccination rate just wasn’t high enough amongst the most susceptible – the elderly. The lesson here is every shot makes a difference and it all adds up, especially for the susceptible groups.

My prayers go out to HKers, especially to our fellow healthcare workers there who are in for the fight of their lives. HKers are a resilient bunch and this hobbit knows that they will rise from the ashes of this crisis stronger. As for us, it ain’t over yet. But even as daily numbers hit more than 20,000 cases, there is no need to press the panic button yet.

¹https://chp-dashboard.geodata.gov.hk/covid-19/en.html (Accessed 2 Mar 2022)

²https://covidsitrep.moh.gov.sg/ (Accessed 2 Mar 2022)