In response to the Newcastle pneumonia epidemic, China quickly launched a vaccine development program, advancing five technical routes in parallel.
On April 12 and 13, two days in a row, the inactivated vaccine, one of the five technical routes, made successive breakthroughs: two inactivated vaccines for the new coronavirus in China were approved to enter clinical trials, becoming the first batch of inactivated vaccines for the new coronavirus to be approved for clinical trials.
Inactivated vaccines, from the name, seem to have nothing to explain: the live virus is extinguished, and the "corpse" is thrown to the immune cells in the body, so that it remembers what the virus looks like, and the next time a similar virus comes, immunity is generated immediately.
If the virus can think, it must be afraid of extermination, because this wave of operation is absolutely brutal, comparable to "The Avengers" in the biggest villain "exterminator", using heat, poison (chemical reagents), radiation and other methods to destroy all signs of life in an instant, all signs of the virus alive are not allowed, " Group extermination" is necessary.
Although crude, inactivation is never simple.
"For the evaluation of the safety and efficacy of inactivated vaccines in animals alone, the research team used nearly seven species of animals, including two species of monkeys, three species of mice, as well as rabbits and guinea pigs, for the attack tests." Yang Xiaoming, president and party secretary of Sinopharm, told Science and Technology Daily that only through strict production processes, testing technologies and quality control technologies can a safe and effective vaccine for public use be produced.
Yang explained that isolating the strain of the new coronavirus is the first step in making an inactivated vaccine; the second step, after getting the strain, is to see if it can be used as the production strain of the vaccine.
Viruses are different from viruses, just like people are different from people, and there are thousands of people with thousands of temperaments. Some strains are suitable for amplification, some are more virulent, and some are milder. ...... will conduct a series of screening to test whether it is suitable as a seed for a vaccine according to the requirements of vaccine development.
The step of "selecting the seed" alone requires a three-stage virus seed bank, with viral strains constantly participating in a "step-up" competition. "Through the test to see if the seeds in the library is good, is not high yield, can produce protective ......" Yang explained, in addition, the purity of the virus is also important, but also need a series of tests to ensure that no impurities.
Only from the original seed bank, the main seed bank, until the "progression" to the working seed bank of good virus, it is possible to go into the "incubator" to start the next step of production.
At the same time, researchers have to prepare the "incubator" that is most suitable for the virus to multiply. The new coronavirus is not "like a fish in water" in all cells, this time the new coronavirus is cultured in vero cells (a kind of monkey kidney cells), the specific culture cell line, culture conditions, etc. need to be figured out, just like raising chickens, fish, pigs, to make them grow well, grow more, and pass on stable generations ......
What makes it even more difficult and dangerous is that all operations dealing with live viruses must be done in a high-security biological laboratory.
Parallel studies are also conducted to validate and figure out the inactivation process and conditions, subsequent purification processes, formulation adjuvants, vaccine doses, etc. They are a set of boring and tedious numbers, but they are related to the inactivation effect and antigenicity effect of the virus, which are closely related to the safety and effectiveness of the vaccine and worth every penny.
When the best of the best new coronavirus strains enter the stage of mass culture, it also enters the production process.
"'Fast' is important, but it must also be 'good'." This is the phrase that Yang often emphasized during this "blitzkrieg" of neo-coronavirus vaccine development. In terms of advanced production process, the production and R&D process, quality standard of testing, and means of testing used by Sinopharm's China Biologicals New Crown vaccine production base are all international leaders.
After culture and inactivation, the purified antigen was obtained by the relevant scientific research team in mid to late February, and then the immunogenicity study of the vaccine was started on a variety of test animals to verify the effectiveness of the vaccine.
It is worth mentioning that all preclinical data were recorded. Due to the sufficient and good research data, the clinical trial of the new class I new drug - novel inactivated coronavirus vaccine declared by Wuhan Institute of Biological Products of China National Pharmaceutical Group was conducted as a combined phase I and phase II, which will greatly accelerate its progress to market.
Beijing KeXing Zhongwei Biotechnology Co., Ltd, which was approved for clinical trials almost simultaneously, has submitted 17 rounds of filings to the Drug Review Center (CDE) of the State Drug Administration (SDA) on a rolling basis since March 13. The new inactivated vaccine for clinical trials has been certified by the China Academy of Food and Drug Administration (CAFA) and clinical trials will start soon.
As early as 1896, German scientist Wilhelm Kohl used broth to culture Vibrio cholerae and made the earliest inactivated vaccine by heating at 56℃ and combining with carbolic acid as antiseptic method. Simple.
Reporter Zhang Jiaxing
Source: Science and Technology Daily
