As pandemic fears engulf the world, scientists across the globe are racing to develop a Covid-19 vaccine. Chinese authorities have been particularly keen to trumpet the country’s efforts in this area and position themselves as helping lead the race to bring the virus under control.
But how close is China really to a breakthrough and who are the organizations vying to produce a vaccine?
Why is it Taking So Long?
The steps to developing any vaccine vary from country to country, but tend to follow similar regulatory milestones. First are exploratory, or pre-clinical tests, where researchers try to prove why a vaccine might protect against a certain disease. These are done through a variety of in-vitro (read: testing in cells, or other low-stakes environments) and animal tests. Scientists might also try to establish a method of manufacturing the vaccine and explain methods of assuring its quality.
After successfully identifying a potential vaccine candidate, the clinical phase of testing can begin. Clinical testing is studying the vaccine in humans, and usually begins with testing if the vaccine is safe and doesn’t provoke an undesired immune response. This is known as Phase I.
Once this is established, various dosages of the vaccine candidate are tested for effectiveness in Phase II. In Phase III, the optimal dose or dosages of the vaccine are tested among a large number of subjects to check for side effects, effectiveness, and other important parameters. Sometimes scientists use the specifiers like IIa or IIIb to describe if they are in the former or latter part of a phase. For something like IIa, it could refer to a mix of testing for immune responses and effectiveness.
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There are many points at which a vaccine can fail — maybe it causes a bad reaction in the first phase, or maybe there is no dosage amount that can effectively immunize the subject against the patient. It’s a tricky, expensive, and long-term process, which is why we’re still waiting on a Covid-19 vaccine many months into the pandemic — and may have to wait for many months more.
Usually regulatory bodies like the FDA in the United States review the results of the vaccine trials throughout, making sure all steps are followed. However, the Covid-19 vaccine is a special case. The pandemic pressure has pushed China and other countries to expedite the process from years into months.
Of the ten Covid-19 vaccine candidates already in the clinical phase, five of these are being developed in mainland China, where finding a vaccine has been made a national priority. By the end of May, the Chinese government had already spent approximately 1.35 billion RMB (191 million USD) to address the global pandemic.
Here is an overview of the five Covid-19 vaccines currently being tested in China. We will keep the article updated as new developments are being made:
1. Ad5-nCov
The developers CanSino Biological Inc. and Beijing Institute of Biotechnology
What it is Ad4-nCov is an attenuated vaccine, which means it uses a weakened version of a virus to deliver enough Covid-19 to provoke the body to naturally develop immunity to it without serious infection.
What stage it’s at III
The latest There are currently two Moderna-sponsored studies being performed. The first, updated on August 18th tests the safety of the vaccine candidate in people. The study uses the vaccine in a two-dose schedule, separated by 21 days. The second study was updated August 21st.
Progress links Phase I is documented here, and Phase II is documented here (links in Chinese).
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2. Inactivated COVID-19 (Wuhan/Sinopharm)
The developers Wuhan Institute of Biological Products and Sinopharm
What it is An inactivated vaccine is one where the infective or harmful portions of the virus are removed and the vaccine is just made of identifying proteins or small portions of the vaccine. Enough of the virus is intact for the body to develop immunity without the person actually suffering the disease, but the virus is no longer alive. This is different from an attenuated vaccine which is still a live virus, just weakened.
What stage it’s at III
The latest On June 16, The Wuhan Institute of Biological Products and Sinopharm announced that the inactivated vaccine candidate did not show any severe side effects during the first two clinical trial phases. It is the first vaccine candidate to enter Phase III clinical trials — and therefore one of the closest to completion.
Progress links Phases I and II are documented here (link in Chinese). Phase III documentation has yet to be updated.
3. Inactivated COVID-19 (Beijing/Sinopharm)
The developers Beijing Institute of Biological Products and Sinopharm
What it is An inactivated vaccine is one where the infective or harmful portions of the virus are removed before the modified virus is infected. Enough of the virus is intact for the body to develop immunity without the person actually suffering the disease.
What stage it’s at I/II
The latest As of April 29, this vaccine candidate is being evaluated for safety and immune response provocation in subjects aged 3 years and above. The study is randomized and double blind, meaning that neither the doctors or the subjects know whether the vaccine given is placebo or not. Only subjects who have not previously had or are at risk for having Covid-19 were included. There are placebo, low, middle, and high dosage groups.
Progress links Phases I and II are documented here (link in Chinese).
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4. Inactivated COVID-19 (Sinovac)
The developers Sinovac
What it is An inactivated vaccine is one where the infective or harmful portions of the virus are removed before the modified virus is infected. Enough of the virus is intact for the body to develop immunity without the person actually suffering the disease.
What stage it’s at III
The latest In April, Sinovac’s vaccine candidate was reported to be undergoing phase I/II trials with subjects aged 18-59 with no prior Covid-19 exposure. 144 subjects were enrolled for the phase I trials and 600 for the phase II tests. The study officially began on April 16, and was estimated to end on December 13 of this year. On May 12, Sinovac also began recruiting for a similar study with subjects aged 60 and over, with an expected completion date of July 30.
On Monday July 6, Sinovac announced that they would be beginning Phase III trials in Brazil after receiving fast-track approval. Entering into this phase makes it one of the closest of these five to completion, along with the Wuhan/Sinopharm vaccine.
Progress links Phase I is documented here, and Phase II is documented here. Phase III documentation is here. The pre-clinical publication can be found here.
5. Inactivated SARS-CoV-2 (IMC/CAMS)
The developers Institute of Medical Biology and Chinese Academy of Medical Science
What it is An inactivated vaccine is one where the infective or harmful portions of the virus are removed before the modified virus is infected. Enough of the virus is intact for the body to develop immunity without the person actually suffering the disease.
What stage it’s at Ia/IIa
The latest As of June 2nd, this study is evaluating the safety and immune response to different doses of the vaccine candidate. 942 subjects ages 18 to 59 years old are enrolled.
Progress links Phases I and II are documented here.
Last updated: August 21, 2020
