Boston University will be permanently closing its COVID-19 Clinical Testing Laboratory and transitioning to a tiered vaccination policy starting May 23, according to an email sent to students from Judy Platt, Chief Health Officer and Executive Director Student Health Services.

From his office at the State House, Baker began the speech by acknowledging the damage of, and lives lost to, COVID-19 — what he called “the worst public health crisis of the last 100 years.”