The first phase I clinical trials were conducted on a small number of volunteers to analyze the safety of the vaccine, the report said. Five of the candidate vaccines have entered phase I/II or phase II trials, which begin to analyze the efficacy of the vaccine.
Among the leading candidates is a vaccine being developed at the university of Oxford. The vaccine will be tested on 6,000 volunteers from next month. The development of the vaccine was accelerated because researchers were inspired by a vaccine against the Middle East respiratory syndrome (MERS) coronavirus.
The leaders also include three vaccines developed by Chinese research institutes and biotechnology companies, as well as a vaccine jointly developed by Germany’s biotechnologies and Pfizer of the United States. The latter is the first to test a new immune technique based on RNA in humans. Vaccines using this technique do not inoculate viruses or virus particles, but directly inoculate genetic instructions to produce antigens that stimulate the immune system.
The report says preventive vaccines must stimulate the immune system to prevent disease. “The problem is that we don’t yet understand how the immune system reacts to novel coronavirus,” said Christian bland, a researcher at the IrsiCaixa research institute in badalona, Spain. We were already running before we could walk. But given our emergency situation, we need to develop a vaccine as soon as possible.”
It is unclear which of the more than 100 candidate vaccines under development are effective at boosting immunity, and how long they will last, the report said. The only way to find out is through a clinical trial, where the vaccine is administered to one group of volunteers, while a placebo is administered to another group of volunteers, and the results of a control analysis are awaited. These trials are usually carried out in people at high risk of infection and take months or years to produce results.
To speed up vaccine development, a growing number of researchers are recommending clinical trials that expose healthy young volunteers to the virus and then compare the incidence of infection between the vaccinated and placebo controls. In this case, it will be possible to know within weeks if the vaccine is effective.