How to improve the resistance against the Omicron variant on the basis of existing COVID-19 vaccines? Sequential booster immunization (also known as "heterologous booster vaccination") is regarded as one of the important exploration directions.

Recently, the interim master data analysis has been completed for phase III clinical trial of sequential booster immunization with the "Recombinant SARS-CoV-2 Fusion Protein Vaccine" (i.e. "V-01") developed by Livzon Mabpharm Inc., an indirect holding subsidiary of Joincare (600380.SH), and critical data have been obtained.

In the afternoon of February 18, Zhu Baoguo, Chairman of Joincare Pharmaceutical Group, told CBN reporter that as of February 18, the company had applied for the marketing of V-01 as a sequential COVID-19 vaccine booster shot to the Chinese review authorities, and also to other countries simultaneously.

It is worth noting that the phase III clinical trial of V-01 sequential booster is the first randomized and double-blind phase III clinical trial all over the world to investigate the sequential booster's protection against the Omicron variant.

V-01 has been approved for R&D since July 2020. It is an innovative recombinant protein COVID-19 vaccine jointly developed by Livzon Mabpharm Inc. and the Institute of Biophysics, Chinese Academy of Sciences. The V-01 molecule consists of interferon, Pan epitope, RBD dimer, and Fc fusion protein.

This sequential booster regimen is designed based on two doses of the inactivated vaccine. The phase III clinical trial of the sequential booster is carried out in Pakistan and Malaysia. A total of 10,722 healthy adults aged 18 years and above who have received both doses of the inactivated vaccine for 3 to 6 months are planned to be injected with V-01 booster or placebo at a ratio of 1:1.

As of the critical data analysis date, a total of 10,241 subjects were actually enrolled, and a total of 110 subjects with primary endpoints after vaccination were monitored (analysis should be performed for at least 103 subjects with primary endpoints as required by the protocol). According to the test results analyzed at this stage, the annual incidence is 6.73% and 12.80% respectively in the V-01 sequential booster group and the two-dose inactivated vaccine group, with a significant difference (P = 0.0012); the absolute protection of V-01 sequential booster is 61.35%, which is significantly superior to that of the two doses of the inactivated vaccine. In this trial, 60 of all valid samples submitted for SARS-CoV-2 genotyping are Omicron as revealed by the first-generation sequencing (the rest are still undergoing the second-generation sequencing), indicating that the V-01 sequential booster is of good protection against COVID-19 caused by Omicron infection. At the same time, no safety concerns were identified.

"A strong superiority standard for relative protection is adopted in this clinical trial, which is different from the traditional control regimen with the blank placebo. An absolute protection of 61.35% obtained this time is based on the protective efficacy of the inactivated vaccine and the prevalence of Omicron. This absolute protection also meets the WHO criteria." Jin Fang, Chief Scientist of Joincare Pharmaceutical Group, told CBN reporter.

Jin Fang also said that due to the use of conventional adjuvants, the V-01 vaccine features good safety and a much lower incidence of adverse reactions than all non-inactivated vaccines. At present, 90% of the raw materials for the vaccine can be sourced in China and the imported raw materials are conventional materials. We have many suppliers, a stable supply chain, and sufficient reserves. We have also carried out development of alternative materials, and are striving to source all materials in China. In addition, the bulk production capacity of the Livzon vaccine commercial workshop can reach 3.5 billion doses/year; the production capacity of the three preparation production lines can reach 120 million doses/month and 1.5 billion doses/year. For emergency cases, contract production may be considered to further expand the production capacity.

from: yicai