WHO: There is no evidence that COVID-19 cures will be immune, and having antibodies does not mean no secondary infection
Recently, the concept of "immunization passport" or "zero risk certification" has become a "protective umbrella" that allows people to return to work without being infected again.
According to CNN's report on April 25, WHO warned that there is currently no evidence that "people who are cured of COVID-19 and produce antibodies can be protected from reinfection."
In response to this vaccine expert Tao Lina said on the 26th that the WHO's statement is based on scientific and very cautious statements. It only says that there is no evidence yet, and no rigorous scientific experiments have confirmed it. There are usually targeted antibodies in the rehabilitated people who are infected by the virus. It is very likely to effectively prevent reinfection, but there is also a certain probability of failure. Out of scientific rigor, the WHO's statement is no problem, but we can't understand that the antibody is useless or the vaccine is useless. To prove that people infected with the virus and having antibodies in their bodies will not be re-infected, they must go through rigorous experiments to make sure that these recovered people will not get sick after being exposed to the virus again before they can say that the antibodies are protective. However, no such research has been conducted globally. Tao Lina emphasized that even if the recovered person is really infected, this type of case is still not convincing. At least tens or hundreds of cases are meaningful.
Another issue that many people worry about is that if the antibody of the recovered person cannot achieve the effect of immunization, is it still useful to use the antibody-producing vaccine to fight the virus? Tao Lina said that the use of antibody-containing serum in the rehabilitation of patients is different from the use of vaccines for prevention. At present, the vaccine is mainly used for prevention. At this stage, the amount of virus that enters the human body is very small. As long as there is a trace amount of antibody in the body, the virus can be dried out. The amount of antibody required for treatment is large, because there are too many viruses in the patient. This is like fighting a fire. When the fire just ignites (the prevention phase), it can be blown out in one breath, but when the fire is burned (the treatment phase), the water gun may not be extinguished.
In addition to "lifetime immunization after one infection", some people in the West have raised the question of "group immunization" strategy. Zhang Wenhong also clearly stated in his answer that the so-called "group immunization" has been confirmed in science and in reality. Not feasible.
Zhang Wenhong pointed out that "in human history, there has never been a precedent for defeating the epidemic through laissez-faire" group immunization "strategies. Science has confirmed that vaccination is the only way to achieve" group immunization ". Recently, China has been developing anti-COVID-19 vaccines. Good news continues to be heard. I hope that scientists in China and other countries in the world will develop a safe and effective new crown vaccine as soon as possible to overcome the epidemic. As for relying on "group immunization" to fight the virus, I suggest that you stop thinking about it. "
Indeed, in order to compete with diseases, the most powerful weapon of mankind is science and technology, and mankind cannot overcome major disasters without scientific development and technological innovation. Vaccines are essential for epidemic prevention and control, and have become the key to human victory over the epidemic.
Historically, vaccine development time has often been measured in years. However, in the face of the rapid spread of the new crown epidemic worldwide, the development of effective vaccines as soon as possible has become an urgent need for all mankind.
"We are flying while making airplanes." Gregory Pollen, director of the vaccine research department at the Mayo Clinic in the United States and editor-in-chief of Vaccine Weekly, described the current COVID-19 vaccine development.
After the outbreak, China completed the virus identification and sequencing in a very short time, and submitted the COVID-19 genome sequence information to the World Health Organization on January 12 for sharing worldwide. This has laid the foundation for virus detection, treatment and vaccine development in various countries.
However, vaccine development is a time-consuming, high-risk, and high-investment task that requires preliminary design, animal experiments, and a total of three phases of clinical trials.
WHO Director-General Tan Desai said in February that the COVID-19 vaccine is expected to be "ready" within 18 months. This is a record high speed.
Tan Desai once again revealed in April that 130 scientists, funders and manufacturers from all over the world signed a statement promising to cooperate with WHO to accelerate the development of a vaccine against COVID-19.
Currently, multi-national research institutions around the world are working together to take a multi-pronged approach from different technical routes and simultaneously promote vaccine research and development. And China is also actively promoting and deeply participating in international cooperation in vaccine research and development, making important contributions to accelerating the global scientific research process and helping the global fight against the epidemic.