Delta outbreak puts pressure on China’s indigenous vaccines


Covid-19 vaccine update

Due to the lack of data on vaccine efficacy, China has had the most severe coronavirus outbreak since the virus first appeared in Wuhan, which has heightened concerns about the quality of its domestic vaccines.

The National Health Commission reported 94 locally transmitted symptomatic infections on Monday, bringing the total number of confirmed active Covid-19 cases in mainland China to 1,603.

Hundreds of them are suspected to be Related to the outbreak The seeds were planted at a busy airport in the eastern city of Nanjing last month. Since then, rapid nationwide spread has ended China’s year-long continuity of small, locally controlled clusters.

The rising number of cases has aroused people’s attention, because neither Sinopharm and the privately-owned Sinoshine have conducted rigorous research to prove that their vaccine is effective against the Delta coronavirus variant.

Decreased effectiveness against sudden mutations in the virus is a problem All vaccinesBut unlike the injections developed by BioNTech/Pfizer, Oxford/AstraZeneca and Moderna, international journals have not published any studies on the efficacy of Chinese jabs on Delta variants, and have not undergone a strong peer review process to confirm the results.

In China, public discussions on this issue are being suppressed.

Last week, a reporter from the People’s Daily, the official newspaper of the Chinese Communist Party, asked at a press conference how many of the Nanjing health authorities’ recent infections were people who had been vaccinated—a phenomenon known as breakthrough infection.

According to people familiar with the matter, the officials did not provide detailed information, but within an hour of raising the question, the reporter received disciplinary action from her boss.

Hundreds of cases have been linked to the outbreak in Nanjing © Oriental Image courtesy of Reuters

Huang Yanzhong, a senior researcher for global health at the New York Council on Foreign Relations, said that the Nanjing authorities should have the data because China closely tracks the vaccination situation and links it with the personal digital health code system.

They may avoid answering this question because “it is becoming a sensitive topic,” he said.

Senior Chinese health experts insist that these vaccines are still effective against the new variants. But they also acknowledged that the prevention rate is declining, and this trend may disrupt vaccination efforts.

Huang said: “If your published data show that the effective rate is getting lower and lower, then you have sent a message in the country that may slow down efforts to achieve herd immunity.”

Chinese infectious disease expert Zhang Wenhong confirmed last week that the breakthrough infection was part of the recent Shanghai airport outbreak. But he added that there were no positive cases in close contacts of the infected person, indicating that the vaccine is still preventing the spread.

Officials from the State Council of China said that early research shows that most people who have been vaccinated in the past year do not need to be boosted, but they are considering high-risk groups (such as the elderly and existing conditions).

After a slow start, China’s immunization rate suffered Government rewards And worries about emergencies have increased rapidly. By Saturday, 1.77 billion doses had been injected.

Residents in Wuhan, China line up to be tested for coronavirus
Wuhan residents lined up for coronavirus testing after reporting a small number of cases, this is the first time since May 2020 © Getty

Thanks to the World Health Organization Approved vaccine According to Bridge Consulting, a research company headquartered in Beijing, 570 million doses of drugs developed by Kexinghe Sinopharm have been shipped to more than 100 countries this year.

But failure to provide evidence of continued effectiveness against the new variants could jeopardize Beijing’s efforts to provide vaccines in developing countries, especially given the mixed results of preliminary studies outside of mainland China.

Research The Chilean vaccination plan published in the New England Journal of Medicine in July found that in samples that included the first Gamma variant infection found in Brazil, Sinovac’s jab was 66% effective in preventing infection. The effective rate for hospitalization is 88%.

other learn A non-peer-reviewed study from Sri Lanka found that in a sample of 282 people, the level of antibody response against Delta produced by Sinopharm injection was similar to that of natural infections.

Other results are not very promising. In Hong Kong, a recent government-commissioned study by the University of Hong Kong found that the neutralizing antibodies of medical staff who received two doses of BioNTech from Germany were about 10 times higher than those who received two doses of Konosing.

Due to the lack of reliable data, some countries that use Chinese vaccines as their main vaccination program have already adjusted their immunization strategies.

According to a report, the neutralizing antibodies produced by Sinovac vaccine dropped significantly after six months. learn Released in July and has not yet been peer reviewed. The researchers found that only about one-third of the participants maintained antibody levels above the detectable threshold.

However, people who received the third injection approximately six months after the second injection had five times higher antibody levels than the group who did not receive the additional injection.

The United Arab Emirates and Turkey have already provided a third dose of Chinese vaccine to some people, and Mongolia will adopt this strategy this month.

The Philippines and Thailand are deciding whether to follow suit or possibly mix the Chinese vaccine with other candidate vaccines.

After hundreds of doctors who were vaccinated with Sinovac were subsequently infected, Indonesian authorities have begun to inject Moderna vaccines for health workers. Malaysia said last month that it will stop using Sinovac once the supply runs out.

Hong Kong government adviser David Xu said that the city will study the impact of intensified injections on people who have received two Huaxing vaccine injections. “Whether the booster dose should be Coxing or BioNTech remains to be tested,” Xu told the Financial Times.

Additional reporting by Shanghai Wang Xueqiao, Hong Kong Nicolle Liu and Singapore Stefania Palma

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