Dr. Colm Henry:

That is a good question. On false negatives, the PCR test is the most sensitive one we have but it does not provide absolute sensitivity. The sensitivity relates to and correlates closely with how symptomatic an individual is.

Clearly, if somebody is actively shedding the virus and is quite sick then one is much more likely to get a positive test when that person actually has the virus. When somebody is asymptomatic it has lower sensitivity. Such is the nature of all tests that they have a stronger sensitivity in symptomatic and asymptomatic individuals. I ask the Chairman to repeat his second part of his question.