Worldwide, the total number of new crown confirmed cases has exceeded 22 million, and the death toll is close to 800000. With the gradual departure of summer, people also began to worry about whether the epidemic will become more and more serious after entering autumn and winter. The new crown vaccine, which is expected to protect the population, has become the hope of the world. < p > < p > today, nature communications, a sub Journal of nature, published a study online introducing a new crown vaccine. The corresponding authors of this study are Dr. Chen Ling of the State Key Laboratory of respiratory diseases, Dr. yuan Zhiming of Wuhan Institute of Virology, Chinese Academy of Sciences, and Dr. Guan Suhua of Guangzhou enbao biology. < / P > < p > this new vaccine is also a kind of adenovirus vaccine, which carries the gene sequence of spike protein, and the sequence is optimized by codon. In mouse model and rhesus monkey model, intramuscular injection can induce immune response, produce specific antibody against spinin and cell-mediated immune response. < / P > < p > to test the protective capacity of the vaccine, the researchers conducted a challenge test on the vaccine 30 days after inoculation, in which a new coronavirus (2019-ncov-wiv04 strain) was introduced into the trachea. In the control group (which did not receive the vaccine), four monkeys showed varying degrees of infection (up to 4.2 million copies per milliliter), and all of them were able to detect virus shedding in throat swabs. On the contrary, monkeys (3 animals) receiving intramuscular injection of the vaccine either failed to detect the virus or just reached the detection threshold (several hundred copies per milliliter) five days before challenge. Seven days after challenge, none of the monkeys showed any signs of infection. The researchers then reduced the dose of the vaccine tenfold (1 x 10 ^ 10 VP) and observed similar results. These results suggest that the immunity produced by intramuscular injection of vaccine can effectively protect rhesus monkeys. < / P > < p > interestingly, in the rhesus monkey model, the researchers set up additional “nasal and oral immunization” groups (3 animals, 5 x 10 ^ 10 VP). The level of specific antibody produced in the vaccinated rhesus monkeys was 1-2 orders of magnitude lower. However, 30 days after inoculation, the monkeys were also challenged with the virus, and there was no obvious infection in the first four days. Six to seven days after challenge, two monkeys showed mild virus infection (about 1000 copies per milliliter). No virus was detected. Afterwards, the researchers found from an independent study that the effect of oral immunization could be ignored. So these protective effects are attributed to nasal immunization. Based on these results, the researchers pointed out that the new crown vaccine showed effective protective effect, while nasal spray immunization is expected to reduce the potential immune problems caused by the adenovirus vector itself. Therefore, as a candidate vaccine, it can be further tested in clinical practice.