From Ho Ching
We are all seeing the number of covid cases rise again in Sg.
The fall in Omicron earlier variant cases had initially masked the rise of the latest BA.4 & BA.5 variants.
But these have now reared its head above the parapet, turning the week on week ratio from less than 1, to now trotting into a swing well above 1.
These 2 more infectious new variants constitute 30% of our new cases.
These 2 variants can also reinfect folks who have been infected before woth the old earlier Omicron variants or other pre-Omicron variants.
In other words, they can escape the antibody defences of prior infections and/or vaccinations.
So what should we do?
Sensibly, many Singaporeans have gone for their vaccine shots, as well as the boosters.
Yup, vaccination and boosters are a first line of defence against severe illness or death from covid, even if they may not fully protect against infection or re-infection by the latest Omicron sub-variants.
There are some 80,000 seniors in Sg age 60 and older who have not had their 1st booster.
More about this later.
Apart from vaccination and boosting, including 2nd booster esp for seniors and those who are immunocompromised, what else can we do?
2 more bits of Omicron BA.4 & BA.5 characteristics are emerging.
The temporal viral load profile may be changing.
Instead of peaking just before symptoms appear, the Omicron variants may peak after symptoms appear. This is why folks very often tested ART+ AFTER symptoms had appeared.
In addition, even for boosted and doubly boosted folks, it takes as long as 9-10 days to turn ART-.
Again, this could mean that the viral load is continuing to increase after symptoms appear, and starts declining a few days after symptoms appear.
This is unlike the earlier pre-Omicron variants where the viral load peaks on average just before symptoms appear, and quickly starts declining within a day after symptoms appear. The exceptions are for the immunocompromised folks and those illness turn serious.
Thus, for the majority, the viral load goes down to non infectious levels within 5-7 days, sometimes sooner for young kids.
This draggy persistence of high viral load detectable with ART for 8-10 days means the latest Omicron sub-variant patients stay infectious for longer.
So what can we do?
We already have vaccines and boosters to protect ourselves from severe or fatal covid infection.
We can now adjust our covid response to minimise transmission to others.
First, as soon as we have any respiratory or infection symptoms, try to self isolate or reduce mask down interactions like meals with others. This is to reduce the chance of infecting others while our viral load continues to build up.
Interestingly, apart from general infection symptoms like fever and headaches, and respiratory symptoms like runny nose, coughs and sore throat, the latest Omicron 4&5 have some distinct and unusual symptoms compared to the earlier pre-Omicron covid symptoms.
The ticklish or itchy throat is one distinctive Omicron symptom.
Interestingly, the latest Omicron variants can cause bouts of sneezing too!
Unusual symptoms include nausea, and headaches that can't be easily soothed with the usual panadol type over the counter medication.
So once we have any of these symptoms, put on a good mask before interacting with anyone, and avoid mask down interactions with others.
Second adjustment is instead of treating ourselves as recovered 7 days from testing ART+, we should extend this to 9-10 days, or wait till we are ART+.
True, the current MOH advisory is to treat ourselves as clear to go out after 7 days if we are vaccinated, or if we are under 12 years old; and self isolate for 14 days if we are not fully vaccinated teenagers and adults.
Folks asked how come we can consider ourselves recovered and free to go out of self isolation even when tested ART+ previously?
This was a practical approach, as the vast majority have been vaccinated and boosted, so that the risks to other are low, and there are only a small proportion of people who are still testing positive after 7 days.
Some of these folks could be the tiny minority of serious but young cases who chose not to go to hospital even when they are struggling to breathe, etc.
[But seriously, folks, even if we are young and healthy, we should go to hospital if our oxygen saturation reading on our oximeters drop below 93%.
This is bcos, seemingly young snd healthy folks can turn very dangerously ill very quickly esp during the 2nd week of infection.
Also, whenever oxygen saturation level goes below 99%, our vital organs will start to get damaged. Such damage could be long term. ]
Back to self isolation period after testing ART+.
Extend this another 2-3 days from the current MOH guidelines of 7 and 14 day for the boosted/fully vaccinated and not fully vaccinated folks respectively.
For teens and adults, fully vaccinated means within 5 months of the 2nd shot of mRNA or protein subunit Novavax, or the 3rd shot of the SinoPharm/SinoVac vaccines.
After 5 months from these 2nd or 3rd shots, a booster shot is required to maintain fully vaccinated status.
For children from 5-11 years old, just 2 shots of the Pfizer 1/3 dose will suffice to be consider fully vaccinated.
For immunocompromised teens and adults, 3 shots of the mRNA (or the now available Novovax protein subunit vaccine) would be required to provide the same level of protection on average, as 2 shots for the healthy immunity folks.
Finally, some elderly folks asked if they should get their 2nd booster shot, when they have had Covid in Feb during the peak Omicron wave. They think of their covid infection as an infection booster dose.
The answer actually depends on themselves and on the covid outbreak situation.
If the the Omicron wave had continued its trend down without the new BA.4 and BA.5 coming onto the scene, and they are generally healthy, then they could consider delaying their 2nd booster shot till later.
But we now know that the Omicron BA.4&5 are already breaking out, and we are likely to see another Omicron wave in July and August period, albeit of the latest sub variants.
We know that prior Omicron infections don't prevent reinfection by the latest subvariants.
We know that an infection is like a vaccine but with unknown dose. So we don't know how much of the adaptive immune system had been stimulated.
With the 2nd booster, we know the dose and we know that the vast majority would have deepen and broaden the 2nd layer adaptive immune system.
It is this deeper layer that helps protect against the infection from turning serious or deadly.
And we know that the 1st booster helps reduce the risk further for everyone.
But old folks start of with much higher risk of serious or fatal infection, and so even with the 1st booster, their risks have come down but remain much higher than for their younger folks.
By having the 2nd booster, it helps bring their risks down by 2/3 less than after their 1st booster.
We can think of vaccination and boosting for old folks as a way to make them younger in terms of risk of serious of fatal covid infection.
Covid risk of death doubles every 5-8 years older.
With 2 shots of mRNA, the risk for 80+ year olds, drop to about the same level as their unvaccinated 60+ children.
With the 1st booster, their risks drop further down to be similar to their unvaccinated 40+/50+year old grandchildren/children, or their vaccinated younger siblings in their 60s or early 70s.
With 1st booster, the risk of death is about 1 in 200 for the 80+ year olds. This is reduced by 2/3 or down to about 1 in 600 with a 2nd booster.
With a 2nd booster, the 80+ year olds would reduce their risk of covid death to be similar to a fully vaccinated but not boosted 60 year old, and an unvaccinated 40 year old.
These are based on data from 1st May last year till 1st May this year in Sg, covering the Delta wave last year and the Omicron wave earlier this year, plus data from elsewhere with 2nd booster policy like Israel.
With the latest BA.4 & BA.5 starting the next wave by July/August, vaccinate, boost, for those who have not yet done so, and for seniors go for 2nd boost within 5 months of 1st booster or an infection.
Also, ideally self isolate as soon as we have infection or respiratory symptoms, and test the next day or two to ensure ART-. Even if tested ART-, bit with symptoms, avoid mask off interactions like meals with others, in case our viral load is still in the building up phase.
If tested ART+, extend self isolation to 9-10 days instead of 7 days, for vaccinated folks, or self isolate till tested ARt-.
For ART+ and unvaccinated folks, self isolate for 18-20 days, or till tested ART-, instead of the current MOH advisory of 14 days.
Other covid precautions still hold like checking oximeter readings, watching out for breathlessness symptoms, etc, during a covid infection.
Hope this helps.
Keep well, folks.
Sent from my iPhone