New crown vaccine or not?
Zhang Wenhong: 3 indicators to measure
Our reporter Zhang Jiaxing
On September 16, Zhang Wenhong, director of the Department of Infectious Diseases at Huashan Hospital, Fudan University, gave advice on issues related to the new crown pneumonia epidemic that people are currently concerned about.
Phase III clinical research is of great significance
Both China and other countries in the world look forward to the launch of the new crown vaccine by the end of this year.
Zhang Wenhong said that people hope to obtain global herd immunity through vaccines, and then achieve world intercommunication.
Moreover, with the launch of vaccines, many problems may be gradually resolved. For example, the mortality rate caused by the new coronavirus will drop significantly.
Is the vaccine safe and effective enough?
Zhang Wenhong believes that the safety and effectiveness of vaccines need to be evaluated for a full year next year.
Regarding the listing of the new crown vaccine, Zhang Wenhong especially emphasized the importance of phase III clinical research.
He explained that the vaccine that can be injected has not yet completed the Phase III clinical trial study, which is an emergency vaccination of the vaccine.
"The Phase III clinical study is of great significance. It is necessary to conduct a comparative study on two people (fed and not vaccinated). For example, every adverse reaction of a person who has been vaccinated needs to be compared with a person who has not been vaccinated. Only to find out which adverse reactions are related to the vaccine." Zhang Wenhong said that the results of the third phase of the vaccine clinical study will also provide a key data-the vaccine protection rate and the incidence of adverse reactions.
Regarding the question of whether the vaccine can be used or not, Zhang Wenhong suggested that ordinary people should wait for the vaccine to be officially approved for marketing, and measure it from three aspects: the risk of my country's epidemic importation, the vaccine protection rate given by the vaccine phase III clinical research results, and the poor The incidence of the reaction, the price of the vaccine.
Identification of secondary infection requires strict scientific procedures
"The virus is detected again after a patient with new coronary pneumonia is cured. It does not mean that it is infectious or that there is a living virus in the body." Zhang Wenhong said that the identification of secondary infection requires a very strict scientific process.
In other words, there must be sufficient evidence to prove that the same patient was infected with the new coronavirus twice.
"So far, I know that there are only two cases of secondary infections reported from an academic perspective." Zhang Wenhong said that the number of infected people in the world is now close to 30 million, and only 2 of 30 million are secondary infections. Therefore, To prove that the new coronavirus has the ability to infect a second time, further evidence is needed.
"I don't think this is an established scientific judgment."
From another perspective, Iceland has conducted antibody tracking tests on more than 1,000 infected people for 4 months.
The results showed that the antibodies of these people remained at a very stable level after 4 months.
China has also carried out continuous monitoring of the antibody levels of participants in inactivated vaccine trials for several months. The monitoring results also show that the levels of neutralizing antibodies induced by inactivated vaccines have always maintained a high and stable level.
"These research results are very good signs, meaning that both natural infection and vaccination can provide effective and stable antibodies." Zhang Wenhong said that so far, the performance of the new coronavirus is still normal, and there is no Very rapid changes, or the human body’s immunity to the new coronavirus is rapidly declining.