COVID-19 is uniquely characterized by pre-symptomatic and asymptomatic transmission. Dr. Chaz Langelier explores types of COVID testing, infectiousness and use cases for certain types of tests. He also discusses variants and how they are tracked and states that the mRNA vaccines are effective against the variants. Series: "Osher WISE: Well-being and Integrative Science for Everyone" [Health and Medicine] [Show ID: 37140]