Sat. Oct 1st, 2022
Men in white lab coats and face masks talk to each other.
enlarge Chinese President Xi Jinping learns about the progress of a COVID-19 vaccine during his visit to the Academy of Military Medical Sciences in Beijing on March 2, 2020.

China has approved an experimental COVID-19 vaccine for use in its military after data from early clinical trials suggested it was safe and fueled immune responses, but before larger trials that will test whether the vaccine can protect against SARS-CoV-2 infections .

This is the first time a country has approved a vaccine candidate for military use. China’s Central Military Commission granted approval on June 25, which will take a year, according to a request reported by Reuters.

The vaccine, developed by biotech company CanSino Biologics and the Chinese military, is a type of viral vector-based vaccine. That means researchers started with a viral vector, in this case a common strain of the adenovirus (type-5), which typically causes mild upper respiratory infections. The researchers have paralyzed the virus so that it does not multiply in human cells and cause disease. They then engineered the virus to carry a hallmark feature of SARS-CoV-2 — the coronavirus’ infamous spike protein, which protrudes from the viral particle and allows the virus to grab human cells.

The idea is that, when the harmless vaccine virus is injected into the body, it will essentially present the SARS-CoV-2 spike protein to the immune system, which can then develop anti-SARS-CoV-2 responses. Those include antibodies, which are Y-shaped proteins that monitor the body and detect previously encountered germ invaders by key features. Once a germ is detected, neutralizing antibodies can glow on the germ and prevent it from causing an infection.

In a Phase 1 safety study involving 108 people, the vaccine — called Ad5-nCoV — was found to be safe and could stimulate the production of neutralizing antibodies and other immune responses. However, the study, published in The Lancet, also discovered a potential foil for the vaccine candidate: In people who had been infected with Ad5 in the past, the vaccine did not generate as strong a response to the peak of SARS-CoV-2 protein. . This may be because their immune systems recognized the adenovirus quickly and focused their responses on the viral vector, rather than the nefarious spike.

CanSino said it had since completed a larger phase 2 study looking at safety and efficacy, but has not yet released any results, according to the South China Morning Post. The paper also noted that CanSino has reached an agreement with the Canadian government to conduct Phase 3 studies there. Those studies will look at efficacy and potential side effects in an even larger group of people.

In the meantime, CanSino declined to say whether members of the Chinese military should receive the experimental vaccine or whether it would be optional, according to Reuters.

According to the World Health Organization’s latest count, there are 17 COVID-19 vaccine candidates in clinical trials and 132 others in preclinical development. Many vaccines are being developed in China, but with the now limited spread of the coronavirus there, researchers are working to conduct vaccine trials elsewhere, in areas where heavy transmission continues.

By akfire1

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