There is a gold signboard in the upper left corner of Gansu health code. What does it mean to write two words?

It shows that the holder has been protected by COVID-19 vaccine.

COVID-19 vaccine generally refers to novel coronavirus vaccine. On June 24th, 2020, China CDC successfully isolated the first novel coronavirus in China. At 20: 00 on March 16, the recombinant COVID-19 vaccine was allowed to start clinical trials. On April 13, China COVID-19 vaccine entered the phase II clinical trial; On the same day, an expert group composed of more than 20 scientists, doctors, funders and manufacturers from all over the world issued a public declaration, promising to work together to accelerate the research and development of vaccines in COVID-19 under the coordination of the World Health Organization. On June 19, the first COVID-19 mRNA vaccine in China was approved for clinical trial. 654381Oct 8, China signed an agreement with the Global Alliance for Vaccine Immunization and formally joined the "COVID-19 Vaccine Implementation Plan".