Covid-19: what is happening in China?

Many questions came to me regarding this scenario:

1. How bad is the situation in China?
2. Why is China experiencing the worst of the pandemic so long after the rest of the year?
world?
3. The vaccines used in China don’t work?
4. Will the situation get worse?

How bad is the situation in China?

Answering the first question: of course it’s serious! Similar to the reality experienced in several countries, adaptations were needed to expand the capacity of the service. In an image circulating on the internet it is possible to see an intensive care unit set up in a conference room.

The peak of deaths in absolute numbers is equivalent to that recorded by the most affected countries, such as India with 4,500/day and the USA with 4,400/day. The Brazilian peak was 4,150 deaths per day. They all took place in the first half of 2021, which brings us to the second question. But first, let’s better contextualize the current gravity of the Chinese situation.

Hospital dedicated to treating covid-19 patients in China (Getty Images)

Considering that China’s population is 1.4 billion, the peak deaths/inhabitant is about 2.85 per million inhabitants, well below the peak of 20/million inhabitants recorded by the United Kingdom, the Czech Republic and Romania. By way of comparison, the peak of deaths reached 15/million inhabitants in Brazil and 10/million inhabitants in the USA. Even so, we cannot underestimate the current momentum in China, which is alarming considering the country’s history during the pandemic and the fact that it is the most populous in the world.

Although China has apparently not reached such high levels of deaths/inhabitants, we must consider the fragility of the data, which lack transparency. The Chinese data has been criticized by the international community for stratify the deaths of individuals with comorbidities. Furthermore, the published data are probably underreported given the high probability of not including deaths at home or those occurring in rural areas.

Why is China experiencing the worst of the pandemic so long after the rest of the world?

The explosion of cases, culminating in the current hospitalizations and deaths in China, came about for a few factors:

Abrupt easing of restrictive measures – China has adopted the “covid zero” policy since the beginning of the pandemic. Defended by much of the world’s scientific community, it is already widely believed that it is not the best long-term strategy. Another consensus is that of gradual weaning in situations where a restriction strategy is adopted such as herd immunity generated by the
vaccination and viral circulation. China didn’t do it. It has maintained strict restrictions for nearly three years, escalating them in periods of flight from the virus. In addition to not being the best way to deal with the pandemic from an epidemiological point of view, it turned out to be not the best way to deal with the social aspect either. The population stopped supporting the government after a certain point due to the long-term psychological and social damage of this policy, including the generation of popular uprisings.

With that, China has simply flipped the switch, rapidly increasing the effective breeding rate of a strain that is even more transmissible than the originals.

Low vaccination adherence of the elderly – The first vaccines in China were not released for the elderly, but for adults. With the justification that there is not enough data to demonstrate efficacy and safety in this subgroup, this fact has generated discrediting of vaccines precisely by the most vulnerable part of the population to covid. Despite the progression in the proportion of older adults on a full regimen through the year 2022, one-third had still not received their booster dose as of November of last year. In the case of the population over 80, the situation is even more worrying. The percentage of those who had not yet received a booster vaccine was 60%.

Low herd immunity – It is already known that vaccination provides a drastic reduction in the severity of the disease when the infection is acquired, but a low efficacy in containing the viral circulation. With the virus circulating and causing infections, there is an enhancement of the immune protective effect. Robust herd immunity, in the case of SARS-CoV-2 so far, is built through the combination of vaccination and viral circulation.

The original idea would be to immunize the majority of the population with the vaccine so that if exposed to the virus, they have less chance of complications and also gain more immunity. Most countries had more
aggressive in restrictive measures in the pre-vaccination era and at the start of vaccination, until priority groups had received the immuniser. When the population was vaccinated, tolerance to viral circulation increased. Naturally, this level of tolerance varied from country to country, and according to the times and forms of changes in the restrictive interventions, but most have adopted the
gradual relaxation, with some occasional setbacks.

Healthcare workers at a Covid-19 patient care center on the street in a Chinese city (Getty Images)

China’s plan was to vaccinate everyone before easing the measures. It’s a good plan, but it wasn’t well executed. First, there are pockets of the unvaccinated among the elderly. Among 80+, ¼ did not even receive the first dose, ? did not receive the second and more than half received no reinforcements. In this context, with a history of low viral circulation in one’s own territory and pockets of unvaccinated among the elderly, it was highly predictable that problems would arise. Secondly, with the abrupt release, the curve of cases/hospitalizations and deaths would be more intense, although lasting less. This point is under discussion, because if the conditions are there to adequately meet demand, it should be more agile. But I don’t think it’s ideal to adapt an intensive care unit to a conference room. In addition to the structure not indicated, there probably was not a team with sufficient experience to deal with these cases. Even in the critical phase of the pandemic, several countries have been affected by these factors.

The vaccines used in China don’t work?

Yes they do it. But it is important to contextualize the differences with respect to the rest of the world. The main vaccine platforms used were based on inactivated virus. There are other platforms approved in the country, such as proteins and viral vectors, but they have been used on a smaller scale. The efficacy of mRNA-based vaccines is known to be superior to inactivated virus vaccines, including currently circulating variants. Therefore, one way to increase population protection would be through the integration of other vaccine platforms, which would act in a complementary way to the scheme implemented so far. Something similar to what was done in Brazil, which has rightly bet on heterologous schemes.

What to expect from the future?

The good news is that the worst is apparently over. Reports from China show that the peak of cases occurred in late December 2022, and within a month, demand in Covid-specific clinics has already been reduced by more than 90%. The peak of deaths occurred in early January this year, with a 79% reduction from the peak. There was also a 72% reduction in severe cases. The estimate, released on January 25 of this year, according to the authors of the report, is that 80% of the population has already been infected with SARS-CoV-2. Despite the necessary skepticism in analyzing these data, they make sense.

A point that deserves caution is that this exposure to the virus is not homogeneous and rural areas further away from large centers, for example, have probably not been so intensely exposed. We also recall that, due to the Chinese New Year festivities – which began on 21 January – there was an increase in domestic travel during the period, with family members gathering in their cities of origin. This already raises some concerns about a possible rebound after this initial surge since China’s full opening.

Knowing the variables that influence the transmission of SARS-CoV-2 is essential to understanding what is currently happening in China and the rest of the world.

In general, the level of susceptibility of the population is by far what influences the current epidemiological dynamics. The factors that influence it, in turn, are the immune response after vaccination, infection, or both, and the variants that arise from time to time. These variables explain the new waves of cases and the reduction in severity, fortunately that has occurred over the years.

The long-term trend, perhaps over years, is for there to be global immune confluence as social interactions and travel are uniformly normalized. It will be when we can categorically state that we have gone from pandemic to endemic.

Is endemic a good thing? Not necessarily.