China’s COVID-19 vaccines are going global, but why still in doubt

The World Health Organization (WHO) plans to move two of China’s COVID-19 vaccines for emergency use, what could open the door to wide distribution in low-income countries through the COVID-19 Vaccines Global Access (COVAX) initiative.

A successful result in the coming weeks could boost global confidence in these vaccines, scientists say in research published in the scientific journal Nature. the five different vaccines from China were not widely used in rich countries, but they are already carrying out vaccination campaigns in the south of the globe.

“There is a strong demand for Chinese vaccines“, of Firdausi Qadri, immunologist International Center for Research on Diarrheal Diseases, Bangladesh, in Dhaka.

One of the two vaccines under study is manufactured in Beijing by Chinese state-owned enterprise Sinopharm. The other, called CoronaVac, is produced by the private company Sinovac, also based at Beijing. If they are listed, will join five COVID-19 vaccines already authorized by the WHO, But will be the first to use inactivated viruses Yes the only ones that are not widely used in Western countries.

Vaccines Sinopharm and Sinovac represent most injections given in China, which has so far inoculated 243 million people. More than 45 countries have already approved its use, but the WHO He was among the first strict regulatory authorities to review the data.

“It is very important to have the support of the WHO,” he warns. Rafael Araos, doctor and epidemiologist of University for Development in Santiago, Chile. A positive response will be “Very good news for vaccine developers and for countries interested in receiving these vaccines.”

The problem is that none of these vaccines has presented supporting scientific information to date.

Address the deficit

The approval process for WHO assesses safety, efficiency and manufacturing quality. Approved products can be purchased through agencies in the The United Nations. “Until that happens, it will depend on each country to acquire the vaccines, and most countries will not be able to do so ”, add Qadri.

Vaccines too could help address the current shortage of vaccines available through COVAX, an initiative led by international associations and agencies, including WHO, to ensure that COVID-19 vaccines are fairly distributed.

Until now, COVAX only shipped around 50 million of the 2 billion doses it intends to deliver worldwide in 2021. India must contribute 1 billion doses of your vaccine Covishield, but exports have halted due to the current COVID-19 crisis in the country. Shipments to COVAX of another WHO-listed vaccine produced by the pharmaceutical company Pfizer were limited and none of the Johnson & Johnson. The vaccine Modern it was added to the WHO list on April 30.

“Therefore, Chinese vaccines are very necessary ”, highlighted Gagandeep Kang, virologist Christian Medical College in Vellore, India, and member of a technical group on immunization advising the WHO. The group met on April 29 to review data on the two Chinese vaccines and will provide recommendations on its use soon.

“Inactivated viral vaccines in general have been shown to be less effective than others. However, still exceed the WHO 50% efficacy threshold for emergency use approval, which makes them important for reducing the global deficit, ”he said. Murat Akova, clinical researcher in infectious diseases of Hacettepe University in Ankara, Turkey. “If nothing else is available, I think these vaccines are a good option.”

Scattered data

Chinese researchers were among the first by starting to develop vaccines against COVID-19 early 2020, but full trial results have yet to be released. Some researchers have expressed concern that a lack of transparency could fuel vaccinations, but others say data collection takes time and resources, and it should be available for the two peak vaccines in a few weeks.

“Chinese vaccines they had to be tested elsewhere because the country did not have enough transmission to carry them out ”, of George Gao, who runs the Chinese Center for Disease Control and Prevention, in Beijing.

“Until now, only scattered information has been published by various countries on Beijing’s Sinopharm vaccine ”, indicated Hilda Bastian, an independent scientist studying evidence-based medicine in Victoria, Australia (Sinopharm produces second inactivated virus vaccine in Wuhan). Her he hoped that the WHO would now publish detailed data.

Early December, the United Arab Emirates (UAE) and Bahrain have approved it, what does one of the first COVID-19 vaccines to obtain full authorization in any country. The approval was based on data from advanced stage trials, including a study from the United Arab Emirates involving 31,000 participants. These have shown that the vaccine was 86% effective in preventing COVID-19 after 2 injections, no deaths among those vaccinated. Articles published after the April 29 meeting suggested that the effectiveness of the combined trials in several countries was 78%.

Data has also emerged on CoronaVac clinical trials and national vaccination campaigns, with mixed results. The trials of Brazil and Turkey they revealed yields of 50.7% and 83.5%, respectively. Researchers say the lower figure could be because Brazil includes mild cases of COVID-19 in its tally and that there is circulation of the P.1 variant, which is more transmissible and may be better able to escape it. ‘immunity. The results of an analysis after mass vaccinations in Chile were between those numbers, at 67%.

Vaccination campaign in China

The vaccine CoronaVac and the two vaccines Sinopharm son the mainstay of China’s vaccination campaign, which aims to vaccinate 70% of its 1.4 billion population by the end of 2021. China approved its first COVID-19 vaccines for emergency use in June 2020 and has been put into service. distributes the doses more widely in January.

Until now, the country’s pharmaceutical agency only included Chinese vaccines, who since December approved the two vaccines of Sinopharm; CoronaVac; and a fourth vaccine produced by CanSino organic products in Tianjin, which uses an adenovirus to introduce DNA encoding the SARS-CoV-2 spike protein into human cells.

Last month, the Chinese pharmaceutical agency also granted emergency use authorization for a vaccine produced by Anhui Zhifei Longcom, a company based in Hefei. It works by introducing part of the virus receptor binding domain protein into human cells and is currently undergoing phase III trials in Uzbekistan.

Gao he says that “Chinese vaccines generally offer good protection, but may need subsequent boosters to induce stronger protection. “Mixing vaccines using different technologies or different modes of entry, such as nasal sprays, could be helpful, ”he adds.

Global reach

Chinese vaccines they have already catalyzed vaccination campaigns in more than 40 countries. The country aims to produce between three and five billion doses this year, and others may come from manufacturing agreements with other countries, such as the United Arab Emirates, which makes a version of the Beijing vaccine from Sinopharm, call Hayat-Vax.

For many countries, Chinese vaccines were the only ones available. In others, like Brazil, turkey Yes Chile, where several tens of millions of people have been vaccinated, represent between 80 and 90% of the doses administered. And researchers in those countries are starting to see evidence of its effect on controlling the pandemic.

“Anecdotal reports indicate low incidence of infections, serious illness and death among people fully vaccinated in Brazil ”, emphasizes Esper Kallas, researcher in infectious diseases of University of São Paulo, Brazil. “Because we have access to CoronaVac, we have to use it. I’m not saying it’s the vaccine of choice in the future, ”he says. “The list of emergency uses CoronaVac of WHO it would also validate its use in the countries which led it. The decision to approve it would give confidence ”.

But many questions remain about vaccines. Researchers want more data on how well they protect the elderly, children, pregnant women and immunocompromised groups. They also want to know what types of immune responses trigger blows, how long the protection lasts and how well they work against emerging variants. “The more data we have, the better,” he concludes. Called.

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