The local epidemic is spreading in many places, and it is increasingly urgent to increase the vaccination rate. Since September last year, provinces and cities in mainland China have successively launched the new crown vaccine to strengthen immunization, and launched the third dose of inactivated vaccine.
So, as an inactivated vaccine with wide application, how effective is Sinopharm Beijing bioinactivated vaccine as a reinforcing needle? Recently, the team of Professor Sun Baoqing of the National Center of Respiratory Medicine, the State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, and the Guangzhou Institute of Respiratory Health published the latest research results: Beisheng inactivated vaccine (BBIBP) booster needle significantly induced memory immunity, of which the potency reached 13.2 times in one month after strengthening immunity; it can be inferred that the vaccine strategy implemented today plays an active role in improving the immune efficacy of the masses.
The study, titled Humoral immune response of BBIBP COVID-19 vaccination before and after the booster immunization, was published in the international academic journal Allergy on March 7, local time. Dr. Cheng Zhangkai, Huang Huimin, Zheng Peiyan and Xue Mingshan of the National Key For Respiratory Diseases were the co-first authors of the study, and Professor Sun Baoqing was the corresponding author.
Screenshot of the paper
The study reported on the kinetics, persistence and neutralization of immunity-induced immunity with the Beijing bioinactivated vaccine (BBIBP), as well as the enhanced antibody response triggered by the intensification of needles. Studies monitor humoral responses induced throughout vaccination, such as virus-specific antibodies (SARS-CoV-2-IgA/IgM/IgG), and perform virus neutralization tests.
The study was conducted in a multi-unit (First Affiliated Hospital of Guangzhou Medical University, Fifth Affiliated Hospital of Zunyi Medical University (Zhuhai) Hospital, Dongguan Eighth People's Hospital) and included 353 healthy adult participants (106 men and 247 women) who completed the full study, with an age range of 20-74 years (median: 33), and the participants were sampled at seven time points and the corresponding antibody level test and neutralization antibody test were performed.
Studies have shown that throughout the vaccination process, the titers of the virus-specific antibody SARS-CoV-2-IgG/IgA/IgM peak in the second month after the first injection and then slowly decline. Interestingly, the results of the study showed that the level of SARS-CoV-2-IgG and neutralizing antibody (sVNT) was most significantly changed 1 month after receiving the booster injection (P
Figure 1: Multi-time point monitoring of antibody levels. IgA (green), IgM (purple), IgG (red), sVNT (blue). Drawings of the paper
The study found that after the completion of the two injections, the corresponding neutralizing titer changes showed a significant upward trend. It is worth noting that the titer of sVNT was significantly increased 0.5 months after receiving the booster injection, which was 13.2 times higher than the 6th month and 4.5 times higher than the first peak (Figure 2).
Figure 2. Virus neutralization test results at different time points, the figure shows the alternative virus neutralization experiment. Drawings of the paper
The study further grouped age (i.e., age ≤40 and age >40) and sex, and compared changes in antibody levels at various monitoring sites. The results showed that the changes in antibody titer levels tended to be consistent between different age groups and sexes. SarS-CoV-2-IgG was also measured in relation to sVNT titer levels (r = 0.647, P
In summary, the study found that the immune efficacy of the Beisheng inactivated disease vaccine (BBIBP) in healthy adults was well tolerated and safe, while the humoral immune response was effectively induced after receiving the first two vaccine injections, peaked two months after the initial injection, and then gradually decreased over time.
The study found that the specific antibody SARS-CoV-2-IgG is mainly responsible for neutralizing potency in the humoral immunity process, indicating that it plays a key role in protecting the human body from viral invasion. Booster needles significantly induced memory immunity, wherein the potency reached 13.2 times one month after booster immunization. The researchers said that it can be inferred from this that the vaccine strategy implemented today plays a positive role in improving the immune efficacy of the masses.
The researchers said that this research work has laid the foundation for the clinical application of inactivated vaccine booster needles. More real-world studies of large-scale outbreaks are needed in the future to comprehensively assess the immune efficacy of inactivated vaccines and determine neutralizing antibody thresholds for preventing disease.