Is the Chinese vaccine useful against the Delta variant? “Effective and very safe.” On July 31, Zhong Nanshan, an academician of the Chinese Academy of Engineering, answered clearly when attending a summit event in Guangzhou. He pointed out that China needs an 83.3% vaccination rate to achieve herd immunity. For this reason, he especially called on everyone to pay attention to vaccination.
In just ten days, the Nanjing pandemic has spread to more than 20 cities in 15 provinces in China. On August 1, there were 55 new cases in China. The “Charming Xiangxi” performance in Zhangjiajie, Hunan and Changde’s “Crossing the Purple River No. 3 Cruise” during this round of the pandemic are becoming new gathering places for spreading.
“This shows that a confined environment is an extremely important window for the spread of the new crown virus. In confined spaces such as airplanes, trains, and subways, because the air is not cleaned enough, it is easy to have air cross-infection.” Zhong Nanshan pointed out that this is worthy of great attention.
On July 27, Nanjing City notified that the strain that caused the Nanjing pandemic was the Delta variant. The Delta variant has become the main variant of the spread of new coronary pneumonia in the world.
“When we encountered the Delta variant for the first time in Guangzhou, we still adopted the old methods at the beginning, but it didn’t work. We found that the speed of quarantine of new patients was far behind the speed of the virus. I was also very anxious in my heart at the time.” Zhong Nanshan recalled.
Why does the Delta variant spread so quickly? “The viral load of the delta mutant strain in the human body is 100 times higher than that of the ordinary strain, and its transmission power is stronger; the incubation period in the body is shorter, and it only takes 1-3 days to become onset; it also takes a longer time to turn negative in the body. It lasts for 13-15 days, which is much longer than the 7-9 days for ordinary strains.” Zhong Nanshan pointed out that because of the high viral load in the infected person’s body, the infectivity has increased. For example, 5 generations of transmission occurred within 10 days of the Guangzhou pandemic.
“The Nanjing pandemic is similar to that of the virus strain that caused the Guangzhou ‘5.21’ pandemic in terms of load, infectivity, and concealment. Most patients are mildly ill. The community near Nanjing Lukou International Airport has concentrated outbreaks, and the occupation of the infected population is relatively concentrated. Nanjing. The municipal government took timely prevention and control measures. I think the Nanjing pandemic is under control as a whole.” Zhong Nanshan said.
Most of the earliest infected persons in this round of the pandemic in Nanjing have been vaccinated. Does the current Chinese vaccine have a protective effect on the Delta variant? Should the vaccine be used or not? “Effective and very safe.” Zhong Nanshan said firmly, using a set of verified scientific data to illustrate.
According to him, based on the study of the outbreak of the delta variant of Guangzhou’s new crown virus in May this year, the results proved that the Chinese vaccine is protective. Preliminary statistics of the study show that the protective effect of the vaccine on severe cases is 100%, and the protective effects on moderate, mild, and asymptomatic are 76.9%, 67.2%, and 63.2%, respectively. Related research results will be published later.
“Of the 13 severely ill patients that appeared in the Guangzhou pandemic, 4 were given ECMO, and we were all rescued. None of them were vaccinated.” Zhong Nanshan added.
In the face of the still severe global pandemic prevention and control, what do we need to do? “Don’t relax, we must always pay attention to the prevention and control measures of the community and the establishment of herd immunity.” Zhong Nanshan emphasized that in densely populated and poorly ventilated places, we must wear a mask.
In Zhong Nanshan’s view, natural immunity is unrealistic, unscientific, and inhumane. “Mass vaccination to achieve herd immunity requires two to three years of global collaboration. At present, China has the largest number of vaccinations, but due to the large population base, the proportion of vaccinations per 100 people in China is not high. In China, A vaccination rate of 83.3% is needed to achieve herd immunity.” Zhong Nanshan believes that vaccination should be accelerated next and the development of a more effective vaccine against delta variant infections should be accelerated in China.