I wouldn't say 0%. In the real world, it is between 0.02% to 0.04% after 3 doses for people over 60 but we should also take into consideration when vaccines lost some of its effectiveness due to mutation or waning.
From what I read, it is possible to get over 95% vaccination rate for elderly through incentives, networking, and pressure. If it is only 5% or less of the elderly population that refused to vaccinate, then I think China could manage the surge if it decided to reopen. In the mean time, the Chinese government needs to drive the vaccination of elderly as quickly as possible. And get the 4 dose ready before the reopen if it is ready to do so.
It is definitely possible. Just look at Australia. We have way over 95% of our 50+ population double vaccinated (Pfizer mostly), something like 99%! Booster shots are being administered too but its a little slower, mainly cause for some of us, that 3rd booster made us feel worst than actually getting covid.
I left China right at the start of the pandemic, and travelled between Hong Kong, China and Australia during all this (Visa was quite a challenge to get). I would say, Australia's COVID rules aside from the strict total lock downs were pretty much similar or on par with China's. Hong Kong's were a joke compared to both. We actually had a vaccine mandate, and despite all the noises those anti-vaxers made, Aussies are sheeps and followed along with the government, which was brilliant because our vax rate is awesome. If Aus can do it then no doubt can China.
Aus lost control last year because NSW didn't implement its lockdown early enough and gave up and spilled to the rest of the country. However, with the high vax rate, despite the surges, it levelled off pretty quickly and life is essentially normal again. The death rate for the pop of 25mil is about 20-30 daily from covid. This is all inspite of ScoMo's government's incompetence. There is definitely some take away here for China for its reopening, since Aus was COVID zero for the 1st 1.5 years of this pandemic too.
