Many countries, from China to Indonesia to Brazil, rely heavily on Chinese vaccines to immunize their citizens against coronavirus. But recently, concerns have been raised whether Chinese-made vaccines provide adequate protection against the Delta variant of the coronavirus, which was originally identified in India.
The Delta variant is considered to be more contagious than other coronavirus variants.
Below, you can read the views of Chinese health experts regarding the effectiveness of vaccines produced in China against the Delta variant, which is becoming the dominant variant in the world.
Do Chinese vaccines against the Delta variant work?
China has not made public the results of the effectiveness of its vaccines against the Delta variant, based on large-scale clinical trials or post-vaccination data of persons with this vaccine. It also did not provide detailed information from laboratory tests, but Chinese experts are urging people to be vaccinated against COVID-19 as soon as possible, Reuters reports.
The lack of detailed data on the effectiveness of Chinese vaccines against the Delta variant, has prevented foreign experts from reviewing these vaccines.
Researchers have found that Chinese vaccines are somewhat effective in reducing the risk of symptomatic and severe cases caused by Delta, Zhong Nanshan, an epidemiologist who has helped China’s institutions tackle the COVID-19 pandemic, told reporters.
This attitude is based on the analysis of infections in Guangzhou and Zhong cities, he told Reuters, adding that the results are preliminary and that the sample of this analysis is small.
A spokesman for Chinese manufacturer of the Sinovac vaccine, Liu Peicheng, told Reuters that the preliminary results were based on blood samples from people vaccinated with the vaccine and showed a threefold reduction in the neutralizing effect of the Delta variant.
He said a booster dose, after the two-dose regimen, could quickly trigger a stronger and more stable antibody response, to fight the Delta variant. However, he did not provide further details on the matter.
Antibodies produced by the two Chinese vaccines are less effective against the Delta variant than other variants of the coronavirus, said Feng Zijian, a former deputy director of the Chinese Center for Disease Control and Prevention.
Feng, in an address last week to Chinese state media, gave no further details, including the names of the two vaccines.
Doses of Chinese vaccines can still offer protection, as none of the vaccinated persons in China’s Guangdong province, where the first cases with the Delta variant were first recorded, had severe symptoms of the disease. All severe cases were noted among unvaccinated people.
Jin Dong-Yan, a virologist at the University of Hong Kong, said Feng’s comments were not enough to support the claim that Chinese vaccines are effective against severe cases of COVID-19, which he said needed more data.
Indonesia, which in recent days has recorded record cases with the Delta variant, reported that hundreds of medical workers, despite being vaccinated with China’s Sinovac vaccine, were infected with COVID-19.
However, it is not yet clear whether these health workers in Indonesia became infected with the Delta variant.
Comparing China vaccines with those of the West
A study conducted in May by the Public Health of England, said that the Pfizer / BioNTech vaccine was 88 percent effective against the symptomatic disease of the Delta variant, two weeks after receiving the second dose of this vaccine.
This vaccine, according to this study, is 93 percent effective against the Alpha variant of the coronavirus, which was initially identified in the UK.
Meanwhile, the two doses of the AstraZeneca vaccine were 60 percent effective against symptomatic Delta variant disease, compared with 66 percent effectiveness against the Alpha variant, England Public Health said.
There is insufficient data to show how much protection the Johnson & Johnson vaccine, which is given through a single dose, offers, and health experts in the United States are considering whether to give boosting doses using the vaccines that have been produced. by the mRNA method.
How serious is the epidemiological situation in Guangdong?
Guangdong is the main center of production and export in China and it is in this region, the largest number of cases has been registered with the Delta variant. In China, the first case with the Delta variant was recorded in May.
In the capital of Guangdong province, Guangzhou, so far 146 cases have been registered with the Delta variant and severe cases with COVID-19, have been recorded in Shenzhen and Dogguan city.
As of June 22, no transmission of the Delta variant within China has been reported.
What has China done?
Guangdong Province, which has a population of 126 million, has accelerated its COVID-19 vaccination campaign since the Delta version of the outbreak. On May 19, 39.15 million doses of the vaccine were administered in this province, while on June 20, this figure reached 101.12 million doses.
The cities of Guangzhou, Shenzhen and Dongguan, immediately after the outbreak of new infections, imposed isolation measures in the neighborhoods where people infected with the Delta variant lived and contact cases were also isolated and subjected to a series of tests against COVID-19.
These cities have also required anyone who has traveled outside this province, through the test, to prove that they are not infected with COVID-19.
Epidemiologist Zhong, said that without effective control measures, 7.3 million residents of Guangzhou city would have been infected in the first 20-30 days, after the first case identified with the Delta variant.
