PIKA COVID-19 vaccine is composed of PIKA adjuvant and a stable trimeric form of the recombinant SARS-CoV-2 spike (S) protein as the main antigen component of the vaccine candidate. PIKA immunomodulating technology is a proprietary innovation originated at YS Biopharma and has been utilized in developing several promising clinical stage vaccines and immuno-oncology therapeutic candidates.

The proposed study in the USA is a Phase I, open label, dose-escalation study to evaluate the safety, tolerability, and immunogenicity of a single booster dose of PIKA COVID-19 vaccine in healthy adults, who have completed a primary COVID-19 vaccine series. It is expected to provide useful information about PIKA COVID-19 vaccine as a heterologous booster against dominant or emerging variants in the USA, such as omicron BA.5 or XBB, regardless of previous vaccination or infection history.

Based on previous clinical study conducted at United Arab Emirates, at 5ug antigen per dose, the lowest dose level in the study, PIKA COVID-19 vaccine elicited significantly high levels of neutralizing antibodies against the Omicron BA.5 subvariant, the dominant SARS-CoV-2 variant circulating globally today, when administered as a heterologous third dose in participants who had previously received two doses of an inactivated vaccine.

YS Biopharma remains committed to completing the current clinical studies and regulatory submissions at various jurisdictions in the first half of 2023, while concurrently preparing for its commercialization in those countries and regions.