Researchers of the Chinese Academy of Sciences issued "Nature": inactivated vaccines can prevent severe illness caused by Omilon

New research shows that three doses of COVID-19 inactivated vaccine are expected to provide effective critical illness protection against the Omiljung variant.

On January 28, the journal Nature published a research article led by Wang Xiangxi, a researcher at the Institute of Biophysics of the Chinese Academy of Sciences, showing that the COVID-19 inactivated vaccine booster can achieve protection against severe infection of the Olmikron mutant strain by improving B-cell immune memory.

Screenshot of the paper

In this study, Wang Xiangxi's team systematically analyzed the stock neutralizing antibody titers and memory B lymphocyte antibody lineages in the serum of Kexing inactivated vaccination volunteers.

The above study pointed out that the serum of 60 volunteers who had received two doses (0 and January procedures) and 60 volunteers who had received three doses (0, 1 and 7 months) of the COVID-19 inactivated vaccine was collected and their neutralizing potency on the original and Omicron variants was assessed by live-virus neutralization experiments. The serum conversion rates of Omicron neutralizing antibodies in volunteers receiving two and three doses of COVID-19 inactivated vaccine were 3.3% (2/60) and 95% (57/60), respectively, indicating that inactivated vaccine booster vaccination helped boost the stock of neutralizing antibodies in serum. After receiving three doses of the COVID-19 inactivated vaccine, the average titer of neutralizing antibodies against the Omicron mutant strain in the volunteer blood sample was 15.4, which was 16.5 times lower than the neutralizing antibody against the original strain, but this level was still higher than the neutralizing antibody level produced against the Delta mutant strain produced by the two doses of inactivated vaccine. Real-world data from previous periods in Brazil, Chile and other countries show that two doses of inactivated vaccine have a critical illness protection efficiency of more than 80% for Delta mutant strains.

The Omikejong variant has a high proportion of breakthrough infections for all types of vaccinators at home and abroad, but the general symptoms of patients are mild. Studies have shown that serum stocks of neutral antibodies are not sufficient to adequately contain breakthrough infections, so why is it effective in providing critical illness protection?

The above studies showed that 323 fully human antibodies were successfully obtained from the NEW CROWN-specific memory B lymphocytes of multiple three-dose COVID-19 vaccinations, of which 24 strains had excellent inhibitory activity against variants such as Omiljung. After three doses of vaccine immunization, some memory B lymphocytes carry broad-spectrum neutralizing antibodies, when the human body is infected by the Omilon variant, this part of the memory B cells will be specifically activated and proliferated, producing a large number of plasma cells that can secrete highly efficient neutralizing antibodies, thereby achieving severe protection of the Omiljung variant.