Vaccines have been developed quickly and safely during the pandemic, saved thousands of lives, and significantly weakened the link between the infection, serious disease, hospitalisations and death.
Mae'r ddogfen hon yn egluro bod y cysylltiad rhwng haint COVID-19, salwch difrifol, cyfnodau yn yr ysbyty, a marwolaethau wedi gwanhau'n sylweddol.