#Covid #FLiRT

For what it's worth: At an estimated 30% FLiRT (JN.1* (Nextclade) + S:R346T, S:F456L) end of wk 10, the impoverished Singapore Covid monitoring shows reduced ARI levels and reduced SARS2 ARI specimen positivity, when comparing wks 9 and 10.

If the FLiRT subvariants have the capacity to drive Rt over 1, this trend would be expected to turn in the coming weeks.

For comparison: JN.1* reached 50% end of Nov, in wk 48, with ARI cases rising since a few weeks.
Week 11, at extrapolated 40% JN.1* (Nextclade) + S:R346T, S:F456L: Still a downward ARI trend. SARS2 positivity 3%.

And a trend reversal in week 12, with slightly rising ARI numbers and SARS2 positivity, at an extrapolated 60% JN.1* (Nextclade) + S:R346T, S:F456L.

It's a shame that Singapore is left with these limited data. Why wouldn't they at least have wastewater.

Update week 13. No wave so far, no new seqs to compare.
Update week 14. No wave, decreasing ARI numbers. SARS2 positivity among ARI samples has increased to 7.4%, up from 2.3% in week 10. Sadly, Singapore hasn't uploaded seqs since weeks.

Possibly, rising SARS2 infections are masked by lowering influenza infections, as flu positivity among ILI samples is steadily decreasing.

This is the state of guessing based on the impoverished surveillance.

For comparison: Singapore had a substantial spring wave, last year.
Extrapolation with new sequences (last available in covSPECTRUM 26.03.) would see JN.1 Spike + S:R346T, S:F456L (FLiRT) dominant in wk 14.
Update wk 15: Not so nice a signal. But no clear trends in the flu and SARS2 positivities.
Update wk 16: Higher SARS2 positivity, soon at 10%, higher flu positivity among ILI. Is this the potential FLiRT-caused rise in SARS2 infections finally becoming a reality?

Clear signs of a Covid wave (albeit still below last year's May wave) in week 17, with SARS2 positivity among ARI samples at 18%.

No new sequences since weeks in covSPECTRUM.

Update wk 18 (29.4.-5.5):

Still rising ARI numbers, SARS2 positivity has plateaued at 16%, while flu positivity went down to 10%. It looks like a minor Covid wave.

Updated seqs on covSPECTRUM:

FLiRT variants are highly dominant as per April 24 (50% beginning of April, wk 14).

Of note, there are almost no KP.3 sequences (15 as compared to 408 FLiRT).

covSPECTRUM queries:

Multilineage JN.1 Spike with S:R346T and S:F456L (FLiRT):

https://cov-spectrum.org/explore/Singapore/AllSamples/Past6M/variants?aaMutations=S%3AR346T%2CS%3AF456L&nucMutations=C22916T%2CT22917G%2CT22926C

KP.3:

https://cov-spectrum.org/explore/Singapore/AllSamples/Past6M/variants?aaMutations=S%3AQ493E&nextcladePangoLineage=JN.1.11.1*

(can't share the link properly, add the star manually)

covSPECTRUM

covSPECTRUM is an interactive platform aiming to help scientists investigate and identify variants of SARS-CoV-2.

Development so far, tabulated.

Note that the covSPECTRUM growth extrapolation, with much fewer seqs, was predicting dominance for wk 14, as the current estimate now shows too.

https://swiss.social/@dominiksteiger/112279678041466048

Dominik Steiger (@[email protected])

Attached: 2 images Extrapolation with new sequences (last available in covSPECTRUM 26.03.) would see JN.1 Spike + S:R346T, S:F456L (FLiRT) dominant in wk 14.

swiss.social
And perhaps the peak has been reached in wk 19. That would mean a considerably lower magnitude compared to last year's XBB wave.
FLiRT sublineages are highly dominant; KP.3 seems not to play a role according to the covSPECTRUM data as of April 25.

Interesting, the MOH itself is seeing a wave now. They even have case numbers. Did I overlook publication of these numbers?

https://www.news18.com/world/new-covid-19-wave-in-singapore-minister-advises-wearing-of-masks-after-25900-cases-recorded-in-a-week-8895361.html

New Covid-19 Wave In Singapore, Minister Advises Wearing Of Masks After 25,900 Cases Recorded In A Week

Singapore grapples with a new Covid-19 wave, recording over 25,900 cases in a week, prompting health measures and vaccine advice

News18
According to their numbers, the wave might even have reached last spring wave height.
Here is their update. Would be nice if they wouldn't have ceased to publish data. Wastewater surveillance could also be considered, for such an advanced city-state.
https://www.moh.gov.sg/news-highlights/details/update-on-covid-19-situation
MOH | News Highlights

Find speeches, press releases, forum replies and parliamentary Q&A.

Covid wave in Singapore, update wk. 20: Highest SARS2 positivity among ARI since wk.9, 21%. I wonder if they are at peak yet.

No new seqs in covSPECTRUM since April 25. FLiRT highly dominant with the last data, KP.3 <10%.

Source:
https://www.moh.gov.sg/resources-statistics/infectious-disease-statistics/2024/weekly-infectious-diseases-bulletin

MOH | Weekly Infectious Diseases Bulletin

Ministry of Health (MOH) is an innovative, people-centred organisation, committed to medical excellence, the promotion of good health, the reduction of illness and access to good and affordable healthcare for all Singaporeans, appropriate to their needs.

Covid wave in Singapore, update wk. 22 (wk. 21 missing): The wave might have peaked in wk. 21, ARI numbers and SARS2 positivity markedly lower.

In terms of ARI, May 2023 wave magnitude. In case numbers and hospitalisations, who knows.

Covid wave in Singapore, update wk. 23 (wk. 21 still missing): Further reduction of ARI cases, stable SARS2 positivity.

In terms of ARI, April/May 2023 wave magnitude. Case numbers and hospitalisations: Who knows, maybe these secrets will be revealed in another press release.