December 22, 2022

expert reaction to current COVID situation in China

In case useful, here are some comments from scientists on the current COVID-19 situation in China.

Prof Sir Andrew Pollard, Director of the Oxford Vaccine Group, and Ashall Professor of Infection and Immunity, Pandemic Sciences Institute, University of Oxford, said:

“In theory ‘zero COVID’ is a reasonable policy to protect populations from the ravages of COVID19, wisely using the time that the policy buys to vaccinate the vulnerable in the population.  It has to be recognised that there are negative consequences of zero COVID lockdowns on schools, businesses, non-COVID health and public acceptance of the policy, but it is likely to save lives and the negative consequences can be managed if effectively implemented and time limited.  The problem for China is that the negative consequences of the policy have been experienced by the population over an almost 3 year period, and the critical missing factor has been the vaccination of the oldest adults, those most vulnerable in society.”

Prof Paul Hunter, Professor in Medicine, UEA, said:

“China is clearly in a very difficult situation at present.  I wrote about this over a year ago when discussing how the pandemic will end https://theconversation.com/how-will-the-covid-pandemic-end-167244.  All countries have had/will have a surge in infections as controls end, or even before they end.  That is inevitable.  What is not inevitable is how many hospitalisations and deaths will occur.

“Figure 3 in this pre-print https://www.medrxiv.org/content/10.1101/2022.10.02.22280610v2 shows very clearly that neither vaccination nor natural infection provides immunity to infection for more than a few months.  But immunity to severe disease (respiratory distress, hospitalisation or death) lasts somewhat longer.  Following vaccination protection (for 50% or more of people) probably about a year but somewhat longer after a natural infection and even longer with hybrid immunity (both infection and vaccination).  Hybrid immunity provides good protection against severe disease probably for a few years at least.

“China has given very few vaccines since about February this year and consequently most of the protection against infection will now have been lost.  Because the Chinese population until recently have not seen much infection very few people will have got hybrid immunity and so a lot of the protection against severe disease will also have been lost now.  In the West most of us now have hybrid immunity and that is why the infection fatality rates are much lower than a year ago.  Additionally it is reported that vaccination of the older population lags behind that of younger people and older people suffer more severe disease.

“We don’t know what the infection fatality rate is in China at present.  Our World in data suggests that deaths are minimal but that conflicts with news reports of large numbers of deaths https://www.ft.com/content/73eba78a-1bdb-4b32-be3e-b0329470b946.  So I am not at all sure what is going on in China at present and how reliable the stats are.  The Our World in data suggests the current wave may have peaked (see below).  But the sharpness and height of the peak would only be seen if the epidemic was limited to a small geographical area or if cases are being dramatically under-reported.  I am struggling to fully understand the Chinese reported statistics.

“So in my view China’s problem now is not because they lifted the restrictions too soon but because they maintained zero covid policy too long after the vaccination campaign so that the protective effect of that vaccination campaign has been largely lost.  Compare this to new Zealand who lifted their restrictions soon after the vaccination campaign and got away with few deaths even though there was, as expected, a surge in infections.  But the current surge in infections is not because of easing control measures as has been pointed out by the WHO as the infection was spreading rampantly even before restrictions were lifted https://www.voanews.com/a/china-s-covid-spike-not-due-to-lifting-of-restrictions—who-director/6876253.html.

“The pandemic is not over as SARS-CoV-2 is here for ever.  Our grandchildren’s grandchildren will be catching the infection.  But in the West at least we are seeing the impact on health services getting less with each wave of infection.  In general I think we can expect that decline to continue though not every new wave is guaranteed to have less impact than the previous one.

“As for the rest of the world, I don’t think the situation in China will pose a substantial additional risk to many other countries.  After all most of the rest of the world has hybrid immunity.  It is said that it is the BF.7 variant of omicron that is driving the wave in China but at a global scale this variant does not appear to have any growth advantage against other variants and is in decline globally https://cov-spectrum.org/explore/World/AllSamples/Past6M/variants?nextcladePangoLineage=BF.7*&.  Another variant could arise and probably will arise, they are doing so all the time but each new variant seems to have decreasing incremental fitness over previous ones (hence the lower peaks).  Also hybrid immunity has provided good cross protection against severe disease from new variants as well as older variants.

“So yes China is in a dark place at present and I do not know how long that will last but I do not think this poses a major escalation of threat to the world more generally.”

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

Prof Sir Andrew Pollard: “Sir Andrew is Director of the Oxford Vaccine Group at the University of Oxford and led the clinical development of the Oxford-AstraZeneca vaccine.  He is chair of JCVI but does not participate in the JCVI COVID19 committee.”

For all other experts, no reply to our request for DOIs was received.