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A few journalists have asked us about the current COVID situation in China, so here are some comments from scientists in case useful.
Prof Mark Woolhouse, Professor of Infectious Disease Epidemiology, University of Edinburgh, said:
“Most experts in epidemiology and global health have believed since early 2020 that Zero Covid is not a viable long-term strategy. A small number of well-positioned countries, including Australia and New Zealand, were able to pursue Zero Covid for a limited period, though that option was not feasible for the UK once coronavirus became firmly established here in February 2020. All countries had to manage the transition to ‘Living with Covid’ eventually. China is the last major economy yet to confront that challenge.
“There several routes to living with Covid.
“First, there is a route through vaccination. Australia and New Zealand took this route and did not release most restrictions until the great majority of their populations had been vaccinated.
“Second, there is a route through natural exposure to coronavirus infection. Most of Africa has taken this route: vaccination coverage remains low but immunity has built up through repeated waves of infection.
“Third, there a combination of vaccination and natural immunity. Many countries, including the UK, have taken this route.
“Because China has energetically pursued Zero Covid since the pandemic began their population has had very little natural exposure to infection so the transition to living with Covid must rely on vaccination. Unfortunately, China’s vaccination programme falls short on two counts.
“First, coverage has been lower than in countries such as Australia and New Zealand, particularly among the oldest and therefore most vulnerable age groups. Even though the currently dominant variant, omicron, is considered less virulent than some of its predecessors, it is still capable of causing large waves of hospitalisations and deaths, as we saw in Hong Kong earlier this year.
“Second, people vaccinated with SinoVac – a Chinese vaccine used widely in that country – are (according to a study earlier this year) three times more likely to suffer severe disease than those vaccinated with one of the mRNA vaccines used in the UK. So, even with better coverage, there is the potential for a much larger wave of death and disease than occurred in Australia or New Zealand.
“From a public health perspective, one option for China is to embark on an energetic supplementary vaccination programme using more effective, imported vaccines. But there is inevitably a political dimension to any country’s Covid response, so this may not happen. If it doesn’t happen then it is hard to see how the cycle of virus incursions and lockdowns will end for many months and quite possibly years.
“Lockdown was not part of any country’s pandemic preparedness planning before 2020. The idea was invented by China in the early stages of the Covid pandemic in a failed attempt to eradicate coronavirus. Almost three years later, China’s experience is illustrating all too clearly the futility of Zero Covid and the inherent limitations of lockdown as a public health intervention.”
Prof Keith Neal, Emeritus Professor in the Epidemiology of Infectious Diseases, University of Nottingham, said:
“It is difficult to know the whole epidemiological picture, the figures provided by the Chinese Government can only be taken as minimums.
“China seems to have nailed its colours to the mast with zero-COVID; quite simply this is now always going to fail.
“China can not open up as:
Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:
“Lockdowns are essentially a short-term measure that buy you time to address the immediacy of the public health emergency. Here, the world and China does now have tools, including vaccines and anti-viral medicine, that can be used to minimise the impact of COVID-19.
“However, a new wave of COVID-19 in China would likely result in high numbers of hospitalisations and deaths. China has a lower vaccination coverage among older populations who are more vulnerable to severe disease. The Chinese vaccines, such as Sinovac and Sinopharm, are not as effective against Omicron variants as the Pfizer and Moderna mRNA vaccines.
“They should use these lockdowns to greatly increase that vaccination coverage, and consider greater use of the mRNA vaccinations available. Global supply is no longer an issue. There is reportedly high levels of vaccine hesitancy among the Chinese populations. Thus enhanced health promotion programmes will likely be needed to greatly increase vaccine uptake.”
Prof Paul Hunter, Professor in Medicine, UEA, said:
“The big problem that China faces is that it is now some time since it completed its last vaccine campaign see below. Figure 3 in this pre-print (https://www.medrxiv.org/content/10.1101/2022.10.02.22280610v2) shows the result of a systematic review into waning of immunity against infection (mainly diagnosed infection) and severe disease. So that immunity against infection following three vaccine doses is relatively short lived (providing 50% protection for only about 3 months on average). Immunity following a prior infection lasts a bit longer maybe about 6 months. So by now most of the people in China who have been vaccinated will have lost their protection against infection.
“But the big concern should be around severe disease. You can see from the same figure that a full (3 dose) course of vaccine provides protection against severe disease for about a year (red line) whereas following infection (the green line) probably around two years. I am extrapolating here, so some uncertainty around the actual numbers.
“However, in the UK the great majority of people have hybrid immunity (i.e. both vaccination and had an infection) and although that doesn’t give much better protection against infection it gives substantially better protection against severe disease and death that probably lasts for more than 3 years if we extrapolate the curve in figure 3.
“So the problem that China has is that because it maintained its zero covid policy even after everyone was vaccinated much of the benefit of vaccination will now have been lost and the country will struggle with higher numbers of severe disease and death especially now most of the benefit of their vaccination campaign will have been lost.
“China is now in a very difficult situation. If they give up on their zero covid strategy now the infections and severe disease will surge in the short term. But if they continue will their zero covid strategy even more people will lose their protection before being exposed to the virus and so severe disease and deaths will be even greater in the long term.
“If I was responsible in China, I would urgently kick start a new vaccination campaign especially for older people, to give everyone some more protection before then relaxing restrictions, pretty much what most Western nations have done. The problem is vaccine fatigue. Will the Chinese be able to vaccinate as many people who would benefit from vaccine before the infection spreads widely?”
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
Declared interests
Prof Mark Woolhouse is a member of the Scottish Government’s Standing Committee on Pandemic Preparedness and author of The Year The World Went Mad (Sandstone Press).
Prof Keith Neal: “No interests.”
Dr Michael Head: “No COI to declare.”
Prof Paul Hunter: “No conflicts of interest.”