HOW SERIOUS IS THE CURRENT WAVE?
There is no evidence that the current XBB wave is causing a significant increase in mortality or severe illness, said Dr Paul Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection.
“The main impact has been in terms of the extended MCs (medical certificates), as well as hospitalisations for individuals who have a mild illness but (have) risk factors identified during previous waves to be associated with complications,” he told CNA.
Most patients that Dr Tambyah has seen in the last few days – including a couple of 90-year-olds – have been well, but their family members are “understandably anxious and have asked for closer monitoring”.
“While the number of cases has gone up significantly, the number of ICU cases and deaths has not risen in tandem and remains similar to the numbers at the beginning of August when there were far fewer cases overall,” he added, citing charts on MOH’s website.
It is also important to note that most of the population has likely already been infected – as not all positive cases are reported to MOH, said Associate Professor Alex Cook and Associate Professor Shou Yiyun from the Saw Swee Hock School of Public Health at the National University of Singapore in a joint reply.
“First, this confers individuals who have been infected and vaccinated with ‘hybrid immunity’,” they said.
“Even though reinfections are now increasingly common, and in part contributing to the surge in cases, the severity of most cases is less than those infected earlier in the pandemic, in early waves and even compared to recent Omicron waves.”
This can be seen in ICU and COVID-19 death statistics.
“Before the wave about a month ago, we were seeing around 10 cases a day in intensive care, when on average around 2,100 daily new infections were reported. This has grown, marginally, to 15 as of Monday when about 8,500 new infections were reported,” said Assoc Prof Cook, who is the vice dean of research and domain leader in biostatistics and modelling for the school.
“The country was preparing, earlier in the pandemic, intensive care beds for several hundred patients, so this is far below maximum capacity.”
Today, around two people are dying of COVID-19 daily, which is “substantially fewer” than during the Delta wave a year ago, said Assoc Prof Shou, the lead scientist in the health and lifestyle domain at the Institute for the Public Understanding of Risk and at the Saw Swee Hock School of Public Health.
At that time, with the seven-day rolling average, around 13 people died a day at its peak, where the number of new daily cases were less than 3,800, she added.
The earlier two Omicron waves respectively saw around 11 deaths a day when the number of new daily cases was around 18,000, and six deaths a day where there were around 11,000 new daily cases, Assoc Prof Shou said.
She added: “Two deaths a day during this wave may sound like a high number, but it is comparable to the number of influenza deaths on a typical day before the pandemic.
“The smaller numbers of people in ICU or dying of COVID-19 compared to previous waves are in line with what we would expect when more of the infections have hybrid immunity from past infection and vaccination.”
WILL THERE BE YET ANOTHER WAVE?
Assoc Profs Cook and Shou think this is unlikely.
“Most of us have been infected, (so) the virus is running out of people to infect for the first time, which imposes a limit on the growth of the epidemic,” they explained.
“MOH publishes a weekly growth rate in the number of cases. This shows how much the epidemic is accelerating or decelerating, much more clearly than looking at the numbers of new daily cases, which jump around from day to day.”
The two experts pointed out that the data showed the wave stopped accelerating over a week ago; it has grown since but at a slower pace.
“Extrapolating the weekly growth rate tells us to expect the peak of the wave to be upon us soon, and so the growth in severe cases should likewise crest in a week or so afterwards,” added Assoc Profs Cook and Shou.
While more severe cases or deaths are expected, these numbers will be “lower as compared to past waves and of a magnitude the healthcare system can absorb”, they said.
“Of the four large community waves, excluding the wave of 2020 that was mostly confined to migrant worker dormitories, this is shaping up to be the mildest, even though it is not the smallest.”