A vaccine developed in China appears to be safe and may protect people from the new coronavirus. Those who received a single dose of the vaccine produced certain immune cells, called T cells, within two weeks. Antibodies needed for immunity peaked at 28 days after the inoculation. The trial is the first step in testing the vaccine and was intended mainly to verify its safety.

from Times of India https://timesofindia.indiatimes.com/home/science/covid-19-coronavirus-vaccine-shows-promising-early-results-in-china/articleshow/75911760.cms