Whether the immune response induced by new coronavirus infection is durable is one of the focuses in the field of public health. Because this is related to the possibility of secondary infection, and whether vaccination has universal clinical significance to curb the spread of the virus. Recently, the latest research from the Shanghai scientific research team brought good news: they found that the neutralizing antibody in the serum of patients with new coronavirus infection lasts for a long time, and memory T cells are also more durable for the antigen of new coronavirus. This not only reduces the possibility of antibody dependent enhancement (ADE) effect, but also provides protection against secondary infection for the infected population. In addition, they found that although the current research and development of the new coronavirus vaccine is mainly aimed at the new coronavirus 614d, it also has the ability to neutralize the currently prevalent new coronavirus variant 614g. The corresponding authors of this paper are Chen Saijuan, academician of national translational medicine center, Shanghai Institute of Hematology, State Key Laboratory of medical genomics, Ruijin Hospital Affiliated to Shanghai Jiaotong University Medical College, and Professor Lu Hongzhou of Shanghai Clinical Center of public health. The co first authors are Dr. Tan Yun, Dr. Liu Feng and Dr. Xu Xiaoguang from national translational medicine center, Shanghai Institute of Hematology and State Key Laboratory of medical genomics, Ruijin Hospital Affiliated to Medical College of Shanghai Jiaotong University; Dr. Ling Yun and Dr. Guo Mingquan of Shanghai Public Health Clinical Center; and Huang Weijin, researcher of China Academy of food and drug control. The duration of adaptive immunity triggered by sars-cov-2 infection is of great clinical significance for evaluating the possibility of secondary infection and the effectiveness of vaccination. In the previous study, the researchers collected serum samples from 17 patients with covid-19 who were 6-7 months after diagnosis and tested for IgG antibodies. The results were compared with those from 2 weeks to 2 months after infection. < / P > < p > the researchers found that all samples were positive for anti sars-cov-2 s protein and N protein. It should be noted that in the pseudovirus assay, 14 samples obtained 6-7 months after infection showed significant neutralization activity, and there was no difference in blocking cell entry of 614d and 614g variants of sars-cov-2. In addition, in 10 blood samples from 6-7 months after infection, the researchers found that CD4 + and CD8 + cells were increased after stimulation with sars-cov-2 antigen through memory T cell test. In conclusion, these results suggest that persistent anti sars-cov-2 immunization is common in convalescent populations, and that vaccines developed from 614d variants may also provide 614g protection against the current 614d variant of sars-cov-2. < / P > < p > persistent neutralizing antibody activity is essential because they not only reduce the possibility of antibody dependent enhancement (ADE) effect, but also provide protection for infected people against second infection. The researchers noted that in two cases with mild / moderate disease phenotype with low viral load during hospitalization, neutralizing antibody activity levels were also relatively low at 6 months after infection. This may indicate that there is a correlation between the viral load of sars-cov-2 and the intensity of long-term humoral immune response. < / P > < p > at 6-7 months after diagnosis, plasma samples from two other patients with severe / severe symptoms showed relatively high neutralization activity against sars-cov-2, indicating that the response of B cells to sars-cov-2 was restored during recovery. Effective immune repair mechanism. More research is needed to confirm these possibilities. In addition, genomic epidemiological studies have shown that the genome of sars-cov-2 has been relatively stable since its emergence in December last year, although the recent d614g mutation in the S protein of the virus seems to increase its binding affinity with the host receptor ACE2. The researchers found that plasma samples from patients infected with new coronavirus type 614d also had strong neutralization effect on the 614g variant of NCV, which may be due to the fact that most antibody recognition sites are not near 614d / g. < / P > < p > in fact, other studies have shown that antibodies isolated from patients infected with Xinguan 614d variant can neutralize the mutant d614g in different experimental environments. Therefore, the researchers concluded that this cross protection could also significantly reduce the risk of ADE against the d614g mutant after vaccination with the vaccine designed based on the new crown 614d. In addition, this work indicates that memory T cells have a persistent response to sars-cov-2 antigen, which is consistent with the previous academic study that high levels of IFN – γ are present in serum during convalescence. This is similar to that after SARS CoV infection: memory T cells are also long-term. Although this study needs longer observation time in the future, the researchers found that all patients, including mild symptoms, can produce cellular immune response to sars-cov-2 antigen, which makes it possible to prevent secondary infection. In conclusion, this study shows that most of the convalescent covid-19 individuals have a sustained immune protection. It is also speculated that vaccination against sars-cov-2 infection may trigger a relatively long-lasting immune response, and that people exposed to the d614g variant may also be protected by a vaccine designed with type 614d sars-cov-2. Global Tech