Positive results from phase I clinical trials of a novel coronavirus vaccine candidate developed by a Chinese team have been reported in a paper published in the lancet.
Scientists in the United States, the United Kingdom and other countries have praised the progress made in the development of a covid-19 vaccine.
Robert scully, chairman of the department of infectious diseases at the university of California, San Diego, told xinhua that volunteers given three different doses of the vaccine candidate all developed neutralizing antibodies and t-cell immune responses against novel coronavirus and showed good tolerance.
Within 28 days of vaccination, most people had more than a fourfold increase in antibodies, an “encouraging” result.
The British empire, says Daniel altman, a professor at the institute of immunology is this report will be coronavirus vaccine clinical trials of the first paper, vaccine induced produced the neutralizing antibody response associated with vaccination dose, volunteers also have no serious adverse reaction, so the beginning “very good”, “quite comforting” test results.
“The clinical trial results from the Chinese team send a positive message to the international community that this vaccine may be effective in preventing novel coronavirus infection, which is very important for epidemic control,” said Stanley perlman, professor of microbiology and immunology at the university of Iowa.
Clinical trials conducted by the China academy of military medical academy of military sciences, biotechnology research institute academician of age and the centers for disease control and prevention in jiangsu province, deputy director of the team, led by professor feng-cai zhu et al, experimental vaccine is a recombinant adenovirus vector will be coronavirus vaccine, harmless after using modified adenovirus type 5 as the carrier, to the human body will be coronavirus spike protein gene.
The 108 adult volunteers, aged between 18 and 60, were divided into groups and given different doses of the vaccine.
Age in the lancet, a press release, relevant results should be treated with caution, the development will be coronavirus vaccine will face unprecedented challenges, and can cause immune response doesn’t necessarily mean that it protects people from will be coronavirus infection, the latest achievements “shows will be coronavirus vaccine development good prospects, but from the vaccine to let all of us use the stage there are still a long way to go”.
Experts are also cautious about the prospect of adenovirus vector vaccines, noting that one of the major challenges is to overcome “preexisting immunity” and that further clinical trials are still needed to verify the vaccine’s effectiveness in preventing novel coronavirus infection.
According to introducing, the majority of people have been infected with 5 type adenovirus in the course of growing up, inside the body may exist antibody to attack vaccine carrier, reduce the effect of vaccine, this is “preexistence immunity”.
The data showed that volunteers with high levels of adenovirus preantibody showed a relatively weak immune response to novel coronavirus infection after vaccination, a limitation common in other adenovirus vector vaccines, scully said.
“As the body’s immunity to adenovirus persists, the immune response to the vaccine becomes weaker and weaker,” scully said.
If the immunity induced by the covid-19 vaccine against the type 5 adenovirus vector declines rapidly, it is necessary to re-vaccinate every two years, and it is likely that covid-19 vaccines with other types of adenovirus vectors will be developed as an alternative vaccine for re-vaccination.
Novel coronavirus is a novel virus with no known cure, said zhang wenwen, a professor of epidemiology and associate dean of the university of California, Los Angeles school of public health.
The primary purpose of phase 1 trial is to observe the physical reactions and side effects of inoculation in volunteers. Phase 2 and phase 3 clinical trials need to further verify whether the vaccine is effective in preventing novel coronavirus infection through a randomized, double-blind, controlled method.
The experts also stressed the importance of strengthening international cooperation to speed up the fight against covid-19.
According to the world health organization, more than 120 vaccine candidates are being developed worldwide.
‘there is a great diversity of forms of covid-19 vaccine being developed around the world, giving different information about protection capacity, safety, sustainability, and ease of production and supply,’ Mr. Altman said.
Altman stressed that the development of a covid-19 vaccine should not be viewed as a race.
By coolly assessing the strengths and weaknesses of each candidate vaccine, it is possible to find the best solution.
Achieving this goal will require the utmost effort of international cooperation.
There is a lot of pressure on all sides to start producing a vaccine before the end of the year, but “we should all be clear that what we need is a vaccine that is proven to be safe and effective”.