Asymptomatic =/= Immune

I didn’t realize until last night that this was a point of confusion.  If my spouse didn’t get it, despite my many rants about asymptomatic spread for the last couple of months, then undoubtedly there are others who don’t get it either.

To be asymptomatic means that you’re infected but not showing symptoms.  This might actually mean you’re pre-symptomatic (you’ll eventually have symptoms) or that for whatever reason, you’ll never develop symptoms.  However, you are still infected, and you can spread the virus (or other infectious agent, but these days, we’re mostly talking about the SARS-CoV-2 virus that causes COVID-19) to anyone who is not immune.  If you are an asymptomatic COVID-19 carrier, you are infected.  You are not immune.  You will most likely eventually develop immunity.  To be asymptomatic is good for you, but bad for everyone around you, because you could be (and probably are) unknowingly spreading the virus.

If you are asymptomatic, you will (assuming 100% accuracy for all tests, which is a huge oversimplification)

– test positive for the antigen (virus)

– test negative for the antibody (proteins created by the body to fight the virus)

– be able to spread the virus to others

To be immune means you have the antibodies to the virus (or other infectious agent).  At some point, you either were infected with the virus and successfully cleared it from your system or you received a vaccine (which, on May 28, 2020, we don’t yet have anything other than a bunch of prototypes being tested).  If you are exposed to the virus again, your body has its defenses prepared to essentially kill on sight (again, oversimplification).  You are very unlikely to carry the virus to someone else.  To be immune is good for you and everyone around you.

If you are immune, you will (again, assuming 100% accuracy for all tests)

– test negative for the antigen (virus)

– test positive for the antibody (proteins created by the body to fight the virus)

– not spread the virus to others

The entire point to masking and social distancing is the same point as safer sex measures: you have to assume that you (and everyone else) are infected and capable of spreading the virus unless you have concrete proof that you cannot.  Concrete proof means a positive antibody test, because you could have tested negative for the antigen (virus) yesterday and been infected immediately after.

Also, on a related note, we don’t yet know for sure how long immunity lasts.  Hopes are for a minimum of 12 months, but we literally can’t know for sure until people who have tested immune (positive antibody test) lose that immunity (without a confounder like HIV attacking that immunity) or don’t.

Trying to find citable sources for all this that aren’t written in overly scientific language and/or behind a paywall is a fun challenge.  There’s this article, which isn’t exactly a peer-reviewed source but does explain things rather simply.  I suppose Johns Hopkins is a better source, but it doesn’t make the distinction in quite the way I think is needed.  Hopefully they’ll help explain this further, though.