A new vaccine for COVID-19 employing a receptor-binding domain-dimer-based platform achieves 87.6% efficacy against severe to critical illness.
A novel vaccine against COVID-19, ZF2001 (Zifivax), from the China-based developer, Zhifei, that builds its protein subunit platform with a receptor-binding domain (RBD)-dimer demonstrated safety and efficacy in a phase 3 trial. Lead author Lianpan Dai, PhD, CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China, and colleagues reported an overall efficacy of 75.7% in preventing COVID-19; with 87.6% (95% CI, 70.6 to 95.7) efficacy against severe to critical illness and 86.5% (CI 38.9 to 98.5%) against mortality.
The trial was conducted between December 12, 2020, and December 15, 2021, in regions where the delta variant was initially prevalent, but with alpha and kappa variants also encountered. The investigators reported that efficacy against alpha was 92.7% in short-term follow-up and 88.3% in long-term; 81.4% and 76.1%, respectively against delta; and 84.8% and 75.2%, respectively for the kappa variant. There were comparable adverse events reported in active and placebo groups, with most (98.5%) of grade 1 or 2, and there were no vaccine-related deaths (determined within 7 days of final dose).
Chongqing Zhifei Biological Products Co., Ltd. engages in the wholesale of biological products and vaccines. Its main products are meningococcal group A&C conjugate vaccine, meningococcal polysaccharide vaccine, mycobacterium vaccine, Haemophilus Influenzae type b conjugate vaccine, and freeze-dried live attenuated hepatitis A vaccine. Its other activities are biotechnology research, development, consulting; import and export, and storage services. The company was founded on July 20, 1995, and is headquartered in Chongqing, China.