Frontrunners in global race for COVID-19 vaccine start final-stage trials
Scientists around the world are working on the novel coronavirus vaccine. Currently, there are nearly 150 of them. However, only about 10 vaccines started clinical trials on human volunteers.
In order for a vaccine to be approved, it should successfully pass through several stages of trials: preclinical studies (in vitro tests and animal testing) and three main phases of clinical trials on volunteers, including the safety assessment, a dose determination and efficacy testing.
Well-known pharmaceutical companies, research laboratories and universities of the United Kingdom, the United States, Israel and, of course, China are among the COVID-19 vaccine developers. According to the Chinese national biotechnology group, based on the results of the second phase of clinical trials, its coronavirus vaccine is efficacious and safe. All of the 1,120 volunteers from 18 to 59 years old have developed antibodies without adverse reactions.
“This is the first inactivated vaccine in the world that entered the clinical trial stage and has already shown its safety and efficacy in terms of antibodies production. We will be conducting the third phase of clinical trials in the countries with a large number of coronavirus patients. We need to inoculate people and find out how strongly the patients are protected,” said Shen Shuo, Chief Researcher of the Wuhan Institute of Biological Products.
In total, there are five vaccines in China that are currently undergoing clinical trials. Scientists are using different approaches when developing them. The coronavirus vaccines are developed using the most attenuated virus, and enzymes and proteins encoded for certain tasks, as well as on the basis of nucleic acids.
Since May 15, the scientists from Kazakhstan have been conducting preclinical trials for the inactivated vaccine candidate.
“Currently, five COVID-19 vaccines are being developed on three platforms. The first inactivated vaccine showed that the virus was neutralized by exposure to chemicals. The World Health Organization checked the protocol involved in vaccine development and included it on its list on May 15,” Kazakh Minister of Education and Science Askhat Aimagambetov said.
He said that first the coronavirus vaccine was tested on linear mice. They are the rodents whose populations are increased only by crossing them with mice with a similar genome.
“From June to July, the acute toxicity of the vaccine candidate will be tested on mice and rats and its immunogenicity on ferrets and golden Syrian hamsters. From July to August, the preclinical studies of the vaccine candidate will be conducted on non-human primates. In September, the vaccine will start the clinical trials,” Aimagambetov said.
According to the WHO’s recent report, in the near future three coronavirus vaccines will enter the finish line of clinical trials.
“We are now entering a new phase of vaccine trials, the Phase 3 trials, the ones that will definitely prove whether or not the vaccine is efficacious and safe. The good thing is, we have many vaccines and platforms so even if the first one fails, or the second, we shouldn’t lose hope, and we shouldn’t give up. We are working on the assumption that we may have a couple of hundred million doses at the end of this year, very optimistically. We are hoping that in 2021 we will have two billion doses of one, two or three effective vaccines to be distributed around the world,” said WHO chief scientist Soumya Swaminathan during the virtual press conference.
However, there is a question of how to make sure that everyone who needs the coronavirus vaccination gets it.
“We can achieve this only if all countries join forces. Let’s say we will have fifty or a hundred million doses at the end of this year. Okay. How should the world share that? Should it go only to the countries which have paid for it or are capable of paying for it, to cover their own populations?” Swaminathan emphasized.