Lancet: Chinese scientists are the world's first human clinical trial results of the new coronavirus vaccine announced! Results show that the vaccine is safe and can trigger an immune response quickly

May 23, 2020 /
Bio-ValleyBIOON/--- In a new study, researchers from the Institute of Bioengineering of the Chinese Academy of Military Medical Sciences, The Jiangsu Provincial Center for Disease Control and Prevention, the China Food and Drug Research Institute, the Hubei Provincial Center for Disease Control and Prevention, the National Key Laboratory for Biosecurity of Pathogen microbiome, Huazhong University of Science and Technology and Shanghai Canming Pharmaceutical Technology Co., Ltdfound that the world's first phase I human clinical trial of the COVID-19 vaccine is safe, well tolerated and capable of producing SARS-2 immune responses in human seisticsThe open-label clinical trial in 108 healthy adults showed promising results after 28 days, but its final results will be evaluated after six monthsFurtherclinical trials are needed
to assess whether the immune response caused by the vaccine is effective in preventing SARS-CoV-2 infectionthe findings, published online May 22, 2020 in the lancet journal, are titled "Safety, Tolerability, and immunogenicity of a recombinantavirus-type type vectored COVID-19 vaccine: a dose-escalation, open-label, non-randomised, first-in-in-trial trial." The paper is written by Professor Wei Chen, Director of the Institute of Bioengineering of the Chinese Academy of Military Medicine, Professor Wei Wang of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, and Feng-Cai Zhu, Deputy Director of the Center for Disease Control and Prevention of Jiangsu Provinceimages from Lancet, 2020, doi:10.1016/S0140-6736 (20) 31208-3"These results represent an important milestone, " said Professor Chen Wei,Theclinical trial strainsshown that the single-dose new adenovirus type 5vectorCOVID-19 (Ad5-nCoV) vaccine produces virus-specific antibodies and T-cells within 14 days, making it a potential candidate for further researchHowever, the interpretation of these results should be cautiousThe development of the COVID-19 vaccine faces unprecedented challenges, and the ability to trigger these immune responses does not mean that the vaccine protects humans from COVID-19This results show that there is a promising future for developing the COVID-19 vaccine, but we are still a long way from its popularity"
build an effective vaccine is considered a long-term solution to control the COVID-19 pandemicCurrently, more than 100 candidate COVID-19 vaccines are under development worldwidethe new Ad5-nCoV vaccine, which is evaluated in theofclinical trials, is the first vaccine in the world to be tested in humansIt uses a weakened common cold virus (adenovirus, which is susceptible to infection in human cells but cannot cause disease), and deliversgeneticmaterial that encodes SARS-CoV-2 protrusion proteins into cellsThese cells then produce the protrusion protein and reach the lymph nodes, where the immune system produces antibodies that identify the protoprotein and repel the new coronavirustheclinical trialassessed the safety and ability of the new Ad5-nCoV vaccine with different doses of the new Ad5-nCoV vaccine in 108 healthy adults between the ages of 18 and 60 who were not infected with SARS-CoV-2Volunteers were recruited from a research site in Wuhan, China, and assigned to receive a new ad5-nCo vaccine in low doses (5x10
10 virus particles/0.5 ml, 36 adults), medium dose (1x10
1111
virus particles/1.0 ml, 36 adults) or high doses (1.5x10
111
11virus particles/1.5 ml, 36 adults) after vaccination, the researchers regularly tested the volunteers' blood to see if the vaccine stimulated two branches of the immune system--- the body fluid immune response (the part of the immune system that produces neutralizing antibodies, can fight infection and provide a degree of immunity) and the cellularly mediated immune response (relying on a group of T-cells rather than antibodies to fight the virus) The ideal vaccine may be able to produce both antibodies and T-cell reactions to defend against SARS-CoV-2 the candidate vaccine is well tolerated at all three doses and no serious adverse events are reported within 28 days of vaccination Most adverse reactions were mild or moderate, with 83% (30/36) of medium- and low-dose vaccinators and 75% (27/36) in the high-dose group reported at least one adverse reaction within 7 days of vaccination the most common adverse reactions were more than half of those who reported mild pain at the injection site, fever (46 per cent, 50/108), fatigue (44 per cent, 47/108), headache (39 per cent, 42/108) and muscle pain (17 per cent, 18/108) One participant who received a higher dose of the vaccine reported severe fever and severe symptoms of fatigue, shortness of breath and muscle pain, but these adverse reactions lasted less than 48 hours within two weeks of vaccination, all three doses of the vaccine trigger a certain level of immune response, i.e binding antibodies (can bind to a new coronavirus, but do not necessarily attack it: 16/36,44% in the low-dose group; 18/36,50% in the medium dose group; and 22 in the high-dose group 22 /36,61%) and some participants had detectable neutralizing antibodies against SARS-CoV-2 (low dose group 10/36, 28%; medium dose group 11/36, 31%; high dose group 15/36, 42%) after 28 days, the majority of participants had a fourfold increase in binding antibodies (35/36,97% in low-dose groups; 34/36,94% in the medium dose group; 36/36,100% in the high-dose group), low-dose group and medium-dose group Half of the participants (18/36) showed neutralizing antibodies against SARS-CoV-2, while three-quarters of participants (27/36) in the high-dose group showed neutralizing antibodies against SARS-CoV-2 important, the new Ad5-nCoV vaccine also rapidly stimulates t-cell response in most volunteers: T-cells respond more strongly in volunteers who receive high- and medium-dose vaccines; Further analysis by the showed that within 28 days of vaccination, the majority of vaccinators either had a positive T-cell response or a neutralizing antibody against SARS-CoV-2 (28/36,78 per cent of the low dose group; 33/36,92 per cent in the medium dose group; and 36/36,100 per cent in the high-dose group) however, the authors note that both antibody and T-cell responses may be reduced by the body's higher pre-existing immunity to adenovirus type 5 (Ad5, common cold virus vector ) (pre-existing immunity, referring to pre-existing immunity) -- in this new clinical study, 44% to 56% of the trial participants had a higher pre-existing immunity to Ad5, and therefore the antibody and T-cell response softened "Our study found that pre-existing Ad5 immunity slows the rapid immune response to SARS-CoV-2, while also reducing the peak levels of these reactions," said Professor Zhu Fengcai In addition, pre-existing high Ad5 immunity may also have a negative impact on the persistence of the vaccine-induced immune response "
the authors note that the main limitations of this clinical trial are the small sample size, relatively short duration, and lack of a randomized control group, which limits the ability to detect rare adverse reactions caused by the vaccine , or provide strong evidence of its ability to produce an immune response." Further research is needed before such experimental vaccines become widely available launched a randomized, double-blind, placebo-controlled Phase II clinical trial of the Ad5-nCoV vaccine in Wuhan to determine whether it was possible to --- 250 volunteers in 500 healthy adults received medium dose vaccination, 125 received low-dose vaccination, and 125 volunteers re-enacted the results of the Phase I clinical trial as a control-placebo, and whether there were any adverse in the six months after vaccination This will be the first time participants over the age of 60 have been included in the study, and this is an important target for the vaccine (Bio Valley Bioon.com) References: 1.Feng-Cai Zhu et al.
Safety, tolerability, and immunogenicity of a recombinant adenovirus type-5 vectored COVID-19 vaccine: a dose-escalation, open-label, non-randomised, first-in-human trial Lancet, 2020, doi:10.1016/S0140-6736 (20) 31208-3.
2 First human trial of COVID-19 vaccine finds it is safe and induces rapid immune https://medicalxpress.com/news/2020-05-human-trial-covid-vaccine-safe.html