On June 16, the Phase I/II clinical trials of the new inactivated coronavirus vaccine developed by the Wuhan Institute of Biological Products of China Biology was blinded. The results showed:

Vaccine group vaccinators all produce high-titer antibodies;

There was no serious adverse reaction;

In the 18-59 age group, the 0,28-day program inoculated with two doses of neutralizing antibody positive rate reached 100%.

The world's first novel coronavirus inactivated vaccine Phase I/II clinical study uncovered the blind inactivated vaccine, which means that the virus will lose its infectivity and replication through physical or chemical treatment, but retains the activity of the virus that can cause the human immune response. The prepared vaccine. However, because the protein shell of the virus is easily degraded in the human body, it usually requires multiple vaccinations, and the demand for vaccines is large. According to China Bio, the initial clinical trials of the new inactivated vaccine started on April 12 and took 66 days. The results of the study were obtained for different ages, different procedures, different doses, and different injections. This is also the longest time, the most comprehensive data and the most effective clinical research results of the novel coronavirus vaccine to date. China Biotech pointed out that this phase I/II clinical study is mainly to evaluate the safety and immunogenicity of the novel coronavirus inactivated vaccine.

This clinical trial is a randomized, double-blind, placebo-controlled phase I/II clinical trial, mainly conducted in healthy subjects aged 18-59 years, a total of 1120 people, according to low, medium and high doses and 0,14, 0,21 and 0,28 different procedures of vaccination, focusing on changes in cellular immunity after vaccination. After all subjects completed 2 doses of vaccination, the researchers explored the vaccination immunization program, immunization dose, safety, immunogenicity and changes in antibody levels in the body. The results showed that all subjects in the vaccinated group produced high-titer antibodies. Among them, in the 18-59 years old group, the dose of the neutralizing antibody was 97.6% after the two doses of 0,14 days and 0,21 days of vaccination, and the rate of positive conversion of the two doses of the neutralizing antibody was 0,28 days. 100%. In other words, judging from the current research results, China Bio-novel coronavirus Inactivated Vaccine is safe and effective.

However, clinical trials are not over. Generally, clinical research is divided into 3 phases:

Phase I mainly evaluates the safety and determines safety measurement, with a small number of people;

Phase Ⅱ mainly evaluates the safety of the vaccine, explores the vaccination procedure, and focuses on whether the vaccine can successfully induce antibodies. The number is slightly larger;

Phase III mainly evaluates the safety and effectiveness of the vaccine, focusing on whether the vaccine is effective, with the largest number of people.

Only after the phase III clinical trials are passed, the vaccine can be applied for marketing and mass production. It takes an average of 12.5 years from the beginning of research and development to the completion of phase III clinical trials of a vaccine. However, it is worth noting that in the context of the epidemic, it takes more than 6 months to complete the immunogenicity assessment, and it takes longer to complete the protection test. Therefore, it may take a year to complete the phase 3 clinical trial and finally conclude that the vaccine is safe and effective.

China's novel coronavirus vaccine process

According to data given by the World Health Organization, there are more than 120 candidate vaccines being developed worldwide, and a small number of vaccines have also begun human clinical trials.

At present, there are five main routes for the design of novel coronavirus vaccines globally-nucleic acid vaccines (including mRNA vaccines, DNA vaccines), recombinant genetic engineering (protein recombinant) vaccines, inactivated vaccines, attenuated influenza virus vector vaccines and adenovirus vector vaccines .

At the same time, my country's vaccine development is also in progress. Zhong Nanshan, academician of the Chinese Academy of Engineering, said in an interview:

So far, we have 5 vaccines in the second phase of clinical trials, our speed is not slow. Among these five vaccines, the top ones are mainly adenovirus vector vaccines and inactivated vaccines; currently, one adenovirus vector vaccine and four inactivated vaccines have entered phase II clinical trials in China.

Different from the traditional technical route of inactivated vaccines, adenovirus vector vaccines are emerging technologies. The principle is to use adenovirus, a double-stranded DNA virus with strong infectivity, to integrate the DNA sequence encoding the novel coronavirus antigen through genetic recombination. Into the adenovirus genome, and remove the genes responsible for the reproduction of adenovirus, so that the vaccine can safely and effectively cause the human immune response. Before China Bio released the results of Phase I/II clinical trials of the new inactivated vaccine, on May 22, the international academic journal The Lancet published a new coronavirus vaccine developed by the team of academician Chen Wei of the Chinese Academy of Engineering; It is a new adenovirus novel coronavirus vaccine.

The paper points out that the study was an open-label test conducted in 108 healthy adults and evaluated the novel coronavirus vaccine using adenovirus Ad5 as a carrier: rapid specific T cells were found on the 14th day after vaccination Response, and the humoral immune response to SARS-CoV-2 reached its peak on the 28th day, and no serious adverse events were found. Academician Chen Wei also gave an additional explanation for this research result. She pointed out that the test showed that a single dose of the new adenovirus novel coronavirus vaccine can produce virus-specific antibodies and T cells within 14 days, making it possible to further the study.

However, these results should be interpreted with caution. The challenge of developing a novel coronavirus vaccine is unprecedented, and the ability to trigger these immune responses does not necessarily indicate that the vaccine will protect humans from the novel coronavirus virus. This result only shows the development of the novel coronavirus. There is hope for vaccines, but there is still a long way to go before everyone can use this novel coronavirus vaccine. Although there is still a way for the application of vaccines, the achievements of vaccine development undoubtedly give people confidence and hope in the fight against the epidemic, look forward to more good news on the fight against the epidemic, and hope that the epidemic will end soon.

Author's Bio: 

Rosie Liu works as an editor in CUSABIO, a biotech company. She likes to write articles about biology and health. It is necessary to know more information of the two aspects so that we can live our life in a right way.