One common question I got was “What happens if I get the vaccine and I’ve already had COVID?” Related to that, “Should I get the vaccine if I’ve had COVID?” and “how long am I immune for?”

Strap in friends, we’re going on another “way too long thread”.

So let’s say you got COVID and beat it. Firstly, well done!

Your immune cells saw the virus, figured out some areas to attack, ramped up production, and kicked the bastard’s ass. Maybe it was a short battle or maybe a long one but you came out the other side on top.

And now your memory cells are going to remember. They won’t remember the ‘whole’ virus. They’ll remember the parts they successfully attacked.

That might be the infamous asshole protein. It might be some other part of the virus. Or a few different parts.

Now here’s the thing: we don’t know how long that memory lasts. We know it’s “at least” a few months. It might be longer. It might be your whole life. This virus has only been around a year. We can only know so much about long-term immunity.

You may have read about people getting COVID twice. But that’s only been a handful of reports. Does that mean immunity is short? Or does it mean out of literally millions of infections, a handful were unlucky for some reason.

We don’t know yet. We might find out soon.

So if you got COVID, you’re probably immune for at least a little while. Maybe to the asshole protein. Maybe to some other part of the virus.

Now let’s say you get the vaccine. Remember, the vaccine gives you the mRNA instructions. Your cells make the asshole protein.

If you have immunity to the asshole protein already, your memory cells see the protein and say “this fucking guy...”, call in their friends and knock the piss out of it. Like one punch and it’s out.

If anything, this makes your memory cells stronger! This fucker keeps coming back. Your memory cells are ‘probably’ going to remember it even better next time. It’s like getting a booster shot. At worst you walk away with the same immunity you had before.

If you didn’t get immunity to the asshole protein when you beat COVID last time, then the vaccine will work like anyone else. Now you’ll have memory cells that remember the asshole protein AND the other parts of the virus you beat before.

So how long does immunity from the vaccine last? Again, we don’t know. We can guess and we can hope. But following science means we have to watch what happens, collect data, and learn from what we see.

If we’re seeing lots of reinfections, it’ll mean people will need a booster vaccine. We may have clues by following people’s antibody levels but the hard truth comes from reinfection rates.

There’s probably going to be a half dozen different vaccines or more on the market next year. Maybe some will have longer immunity than others. We won’t know until we get there. Until then, we make the best decisions we can based on what we know today.