German Chancellor Angela Merkel has gone into quarantine after being informed that a doctor who administered a vaccine to her has tested positive for the new coronavirus. Merkel's spokesman said the German chancellor was informed about the doctor's test shortly after holding a news conference Sunday announcing new measures to curb the spread of the virus. Her spokesman, Steffen Seibert, said Merkel had received a precautionary vaccine Friday against pneumococcal infection. Seibert said in a statement that Merkel, 65, would undergo ``regular tests`` in the coming days and continue with her work from home for the time being.