Since our last newsletter, the fifth wave of Omicron BA.2 has burned aggressively through Hong Kong and we are temporarily in the unenviable position of having the highest per-capita Covid mortality rate in the world. We have seen our patients leave the city at the highest rate since we started our practice more than 27 years ago. We are here, working both within the clinics and supporting the government response. We remain confident that we have turned the corner and a return to a more normal life is within touching distance.
We have consistently explained the importance of achieving high vaccination rates but also, most importantly, that vaccinations are given from the most vulnerable members of the population down. There is no evidence to suggest that the Omicron BA.2 variant hitting Hong Kong is intrinsically any more serious than other Omicron variants. The high mortality rate in Hong Kong is a result of three factors:
- Low levels of natural population immunity
- Low levels of vaccine-induced immunity in the most vulnerable
- An overloaded health system
In the latest of a series of articles ‘What next for Hong Kong?’ Dr Owens gives a personal analysis of how we ended up in this situation and outlines a strategy to navigate the current situation. His analysis is written under the assumption that the goal is to optimise population health.
All deaths represent loss and grief for families and relatives. From a population health perspective, it is important to analyse the data around mortality. In Hong Kong, the vast majority of the deaths are occurring in the predominantly unvaccinated vulnerable members of our community. Many from long-term residential care homes. The mortality in this population group has been lower over the last couple of years due to the reduction in background infections such as influenza and chest infections. As a result, when we were hit with a sharp and high wave of infections, we saw high mortality in the early phases of the infective surge. Unfortunately, at least in part due to poor policy decisions, the health system was overloaded. This almost certainly increased mortality rates. It is too early to be certain but, with the exception of risks attributable to the overloaded health system, there is no reason to believe that Omicron will be any worse for the younger, healthier and most importantly, vaccinated fragment of the population, than it has been anywhere else in the world.
The countries that have performed best during Covid all pursued elimination strategies. The failure to plan for a transition and, most importantly, the failure to achieve high vaccination rates in the most vulnerable means that Hong Kong has lost its position amongst the best-performing nations, including our immediate neighbours in Southeast Asia. Although we are facing a challenging time, it is important to assess this in context. Regardless of the next few weeks, Hong Kong will end up much better off than the US, UK and the majority of countries in Europe. We are likely to end up with a population mortality equivalent to the best performing European countries, probably somewhere close to the final mortality rates in Denmark.
Fig 1. Cumulative covid deaths per million people. Hong Kong is easily identifiable with the recent rapid surge in mortality.
Epidemiological data suggests that the Omicron wave peaked in Hong Kong earlier this week. This means that we are already at herd immunity. It is important to understand that herd immunity exists in a particular state. By mid-April we will have had something close to 5 million infections. This will be enough to bring the epidemic under control under the current social distancing regulations. If we were to immediately take off masks and move around the city as normal then the decline in infections may begin to plateau. We will continue to have some infections circulating and for this reason, we still need to focus on boosting vaccination rates in the vulnerable. We will also still need some mitigation measures for a few months in order to allow a gradual transition from around 70% immunity to closer to 90% population immunity. This would be the rational plan of a graduated transition to living with Covid. Under this scenario, border controls are already unnecessary and they could certainly be removed very soon. There is no reason why our city could not be getting back to relatively normal life within 2 to 3 months with a transition to a coherent, evidence-based living with Covid strategy.
‘May you live in interesting times’
There is no doubt that the last few years have been very challenging for Hong Kong. In particular, at this moment our hospital system is under extreme stress. We would ask everybody to focus and think for a moment about the amazing nurses, doctors, healthcare workers, cleaners, drivers, shop assistants, domestic helpers and other unsung heroes, for it is they who will pull our great city through these testing times. It is important that as we continue to face challenges and manage through this period of uncertainty, we do not lose sight of the sense of community that makes Hong Kong home. In the not too distant future the flame trees will be in full bloom and we will have our masks off and be smiling again.