Peking University—YHLO Joint Lab Achieved Another Great Result



On June 24th, Peking University—YHLO Joint Laboratory for Molecular Diagnostics of Infectious Diseases published in Journal of Infection(2021 IF: 38.637) an article entitled “Antibody efficacy of inactivated vaccine boosters (CoronaVac) against Omicron variant from a 15-month follow-up study”, which revealed the immune response and protection against the Omicron variant before and after three doses of the inactivated COVID-19 vaccine.

To evaluate the protective antibody response following vaccination, YHLO iFlash-2019-nCoV Neutralizing Antibody Kit and iFlash-SARS-CoV-2 IgG S assay were used to quantify neutralizing and IgG S antibodies against SARS-CoV-2 in plasma.


The study was a follow-up that lasted for 15 months from 2021.01 to 2022.04, in which 116 healthy adult volunteers were included. It was found that an overall protective antibody immune response against both the Omicron variant and the wildtype strain was significantly enhanced after the booster dose of the inactivated COVID-19 vaccine compared to two doses alone. Neutralizing and IgG S antibody levels in the plasma peaked approximately 10–14 days after booster vaccinations and were relatively stable for 60 days. In comparison with the wildtype strain, the ability of most volunteer sera to produce neutralizing and IgG S antibodies against Omicron was considerably impaired. Even when the antibody response peaked 2 weeks after the booster vaccination, a 6.4-fold reduction in the geometric mean titer (GMT) of Nabs and a 2.3-fold decrease in anti-S antibodies against Omicron were observed.

Overall, this is the longest follow-up report available regarding the antibody response of inactivated COVID-19 vaccine boosters against Omicron. An accurate assessment of the change in antibodies against the variant strain after vaccination could aid in the development of optimal immunization regimens. In conclusion, despite the decline in vaccine efficacy against new variants, booster immunizations continue to be an integral part of establishing complete immunological protection among the population.


This was the third study published on SARS-Cov-2 research by Peking University—YHLO Joint Laboratory. Peking University could make good use of the talent and medical discipline, while YHLO is outstanding in technological innovation and commercialization of scientific and research findings, which support the Peking University—YHLO Joint Laboratory to gradually form a cooperation model that combing the manufacturing, teaching and researching together and improve technological innovation capability that helps to create more achievements.




Yin Y, Li X, Qian C, Cheng B, Lu F, Shen T. Antibody efficacy of inactivated vaccine boosters (CoronaVac) against Omicron variant from a 15-month follow-up study. J Infect. 2022 Jun 24:S0163-4453(22)00374-7. doi: 10.1016/j.jinf.2022.06.018.



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