The world's first! XBB vaccine approved for emergency use, with a protective efficacy of over 93% after 14 days of vaccination

On June 8, with the approval of relevant national departments, the recombinant trivalent coronavirus ( XBB+BA.5+Delta variant ) trimer protein vaccine (Sf9 cells) developed by Sichuan University West China/Wesker Biotech, the Weixin® 3-valent XBB vaccine, was included in the emergency use. This is the world's first COVID-19 vaccine approved for emergency use against XBB and other variants. It is expected that the public will be able to receive the vaccine in the next 1 to 2 months.

Image source: Sichuan University West China Hospital Weibo

The Vickin® trivalent XBB vaccine targets the spike protein receptor binding domain (S-RBD) and heptad repeat domain (HR) of the new coronavirus mutant strains XBB and BA.5, and designs subunit vaccine antigens, which self-assemble into stable trimer protein particles, which are purified and mixed and then added with a squalene-based water-in-oil emulsion adjuvant. This innovative adjuvant significantly increases the neutralizing antibody titer of the vaccine, allowing the trimeric protein vaccine to induce a stronger T cell immune response in the body.

Clinical trial data show that the Vickin® trivalent XBB vaccine can induce the production of high-level neutralizing antibodies against variants such as XBB.1, XBB.1.5, XBB.1.16, XBB.1.9.1, XBB.2.3, BA.5, BF.7, BQ.1, BA.2.75, etc. 14 days after vaccination, the protective efficacy against symptomatic COVID-19 disease caused by variants such as XBB.1, XBB.1.5 and XBB.1.9 is 93.28%, and the safety is good.

At the press conference of the Joint Prevention and Control Mechanism of the State Council held on May 8, Chen Cao, a researcher at the Institute of Viral Diseases of the Chinese Center for Disease Control and Prevention, said that the XBB series variant is a recombinant variant of Omicron, which has stronger transmission and immune escape capabilities than the Omicron variant that was prevalent in the early stage. According to the current monitoring data, the proportion of XBB series variants in my country's imported cases in late April this year has reached 97.5%. As of May 8, the main epidemic strain of the new coronavirus in my country has become the XBB series variant. On May 18, the World Health Organization (WHO) COVID-19 Vaccine Composition Technical Advisory Group (TAG-CO-VAC) made recommendations on the update of this year's COVID-19 vaccine composition, proposing that future vaccines should induce neutralizing antibody responses against the global mainstream COVID-19 strain XBB variant.

Wisk Bio is an innovative biopharmaceutical company founded by scientists from the State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, integrating vaccine research and development, production and sales. In December 2022, the recombinant novel coronavirus vaccine (Sf9 cells) developed by Wisk Bio, Wisk Xin®, was approved for emergency use by relevant national authorities and has now been enrolled and supplied for vaccination in more than 20 provinces across the country.

Source: Beijing Daily WeChat Official Account

Intern reporter: Chai Rong