It is running through HK much faster than at any point prior. HK seemed to be the model of how to effectively handle a pandemic based on their prior experience with SARS. Only residents are allowed in, and have to undergo mandatory 21-day isolation in dedicated quarantine hotels. Anyone who tests positive was sent to an isolation ward at a hospital, and anyone who had been in close contact with them was sent to a quarantine facility for 2-3 weeks. Since the pandemic began, HK had just over 200 deaths until the end of 2021 and if I remember correctly only around 10k total cases.

However, some essential workers such as cross-border supply transport and import/export, airline industry, etc allowed to quarantine at home when not working. HK's current spread supposedly comes from two airline industry workers who broke home quarantine in early Jan, one was infected with Omicron, the other with Delta. Last I heard on the news a couple of weeks ago (before infections really went through the roof), something like 90% were Omicron (BA.2 variant), so it seems to be spreading much more/faster than Delta. Once the numbers reached 10K cases per day or so, they stopped reporting detailed breakdowns. They peaked at over 50k/day for a while, but are now down to <30k/day.

I believe there are likely 2 factors behind this. One, due to HK only allowing residents in and subjecting them to a 21-day mandatory hotel quarantine, we've had very few cases get through to the local community in the last year. Previous local "waves" have been on the order of 100 people infected or less. That and general distrust of the government after the events of 2019 have led many people to not get vaccinated at all.

The other is that nearly half of the people who were vaccinated before the current wave received SinoVac's traditional inactivated virus vaccine which is basically ineffective against Omicron. The government now claims it won't protect you from getting infected, but will reduce the severity of the disease.

https://hongkongfp.com/2022/02/26/factwire-sinovac-limits-ho...

Previously the government would send anyone who tested positive to a covid isolation ward at the hospital, and close contacts would be sent to the government quarantine center for 2 weeks (down from 3). However, hospitals and the quarantine center quickly became overwhelmed. Now the tell people to self-isolate at home if their symptoms are mild, and only go the hospital if they feel they need treatment. They also designated a couple of hospitals for covid patients only, and also offloaded some non-covid treatment from public to private hospitals (on government dime).

Here's my anecdote: My wife and I had some mild cold symptoms, so we bought some rapid self-test kits and started testing. After a few days, she started having some mild flu symptoms, and tested positive for 5 days in a row. We self-isolated from each other as much as possible, but there's only so much you can do so in a 230 square foot 1-bedroom flat. I kept having mild cold symptoms, but tested negative for the entire time. One reason this is interesting: she was vaccinated with Sinovac, I was vaccinated with Pfizer/BioNtech (nearly 10 months prior).

If anyone's curious, the HK government has some daily-updated stats websites (which used to give detailed info on when/where/how many cases were detected and where these people had visited according to the local contact tracing app, until cases went above 10K/day, then they stopped) and on vaccinations:

https://www.coronavirus.gov.hk/eng/index.html

https://www.covidvaccine.gov.hk/en/dashboard/

It's possibly worth pointing out that in mainland China, the population doesn't have access to mRNA vaccines at all. So if Omicron spreads wildly there, they may really be screwed.