There are only 103 strains of common cold?

[Charlie_Tan]

Inspired by this thread about virus, I remember a ‘factoid’ I heard a while ago. That there are 103 different strains of virus that cause the common cold. As with many viral infections, once a person’s had it, the immune system will recognize it it won’t hit you again. A kid who’s had rubella, measles or mumps won’t get it again, and as I understand it, it’s a good thing to get those as a kid, since adults suffer much worse from them.

Anyhow.
It feels like I’ve had a huge amount of common colds in my life. I’m not keeping track, but since I keep getting them, it must mean that each time, it’s a new strain, since my body is already immune to the ones I’ve had.
Or not.
So back to the factoid. Are there really only 103 strains? Does that mean that when I suffered through them all, I won’t get common cold anymore? And, subsequently, do older people get fewer and fewer common colds?

[x-ray_vision]

I remember reading the same thing several years ago. The article also said, “That’s why old people rarely get colds, they’ve had almost all of them”.

Not too long ago I read that you do become immune to cold viruses but that the immunity lasts only a few years. I’m going to do a search now.

[x-ray_vision]

This article backs up what I read several years ago.

As you age, you develop immunity to many of the viruses that cause colds. You’ll have colds less frequently than you did as a child, but you’re at increased risk when you are:

* Spending most of your time indoors and in close contact with other people during fall and winter
* Experiencing psychological stress
* Having an allergic reaction that affects your nasal passages

This article backs up what I read not too long ago.

There are over 200 cold viruses for you to catch, and they are all different! When you catch any one virus, the body produces antibodies to that one virus, and you will then be immune to that virus. That immunity is unfortunately only effective for that one virus, and you can still catch any of the other 199 or so. The immunity also wears off over time, so you can still catch that one virus a number of years later.

[x-ray_vision]

Since older people probably don’t have immunity to strains of cold viruses they had when they were younger, my WAG is that they don’t catch colds as much as younger people simply because they are not around as many people to catch them from, e.g., school and work.

[Charlie_Tan]

Huh? Whaddyaknow… Not all e-mail lore is bunk.
I find this interesting, if not mind boggling.
Thanks XRV

[Folly]

< 200 strains? Really?

How often does a new strain appear do to mutation and whatnot? I tried a quick internet search but found nothing.
If it’s not very often, what’s preventing a pharmaceutical company from compiling one mega-vaccine that includes all the strains?

It would probably be expensive and you’d need a booster every few years, but I bet the well-to-do would go for it. Especially the power-execs who lose thousands every time they have a sick day.

[Smeghead]

I sincerely doubt anyone’s ever gone through and catalogued every strain of virus that can cause a cold. Any numbers you see out there will be a rough estimate.

As has been said, you do acquire immunity to a particular strain after you’ve been infected with it, but the immunity only lasts for a few months to a few years.

[Charlie_Tan]

@Smeghead

but the immunity only lasts for a few months to a few years.

Why?
I’m immune to measles, which I had as 4 y.o.

[Smeghead]

It’s a different type of antibody, with memory B cells that don’t survive as long. Long story short, the immunity provoked by a virus on your mucosal surfaces is much weaker than the immunity provoked by a virus in your bloodstream. I could explain in more detail, but the last time I went in depth into this subject, I was accused of quoting a textbook in a smug manner.

[umop_ap_sdn]

@Folly

what’s preventing a pharmaceutical company from compiling one mega-vaccine that includes all the strains?

1.) The 200 or so viruses are not merely strains of the same type of virus;

2.) It would put the cold and flu medicine industry out of business.

[Smeghead]

@Folly

If it’s not very often, what’s preventing a pharmaceutical company from compiling one mega-vaccine that includes all the strains?

Oh, I didn’t see that before. Basically, you’d have to come up with 200 or so vaccines, which would be a HUGE job to start with, and because immunity is so short lived, you’d have to revaccinate every few months. Blame your body.

Which, obviously, would NOT put the pharmaceutical industry out of business - quite the opposite. But it would be such a pain that it just isn’t worth it. At least, I think the occasional cold is less obnoxious than trying to follow that kind of regimen.

[RickJay]

@The Gaspode

Anyhow.
It feels like I’ve had a huge amount of common colds in my life. I’m not keeping track, but since I keep getting them, it must mean that each time, it’s a new strain, since my body is already immune to the ones I’ve had.
Or not.
So back to the factoid. Are there really only 103 strains?

103 colds in your life would be a truly astounding number of colds. Two or three colds in one year is a lot; any more than that and you should see a doctor.

I also suspect people sometimes get bad hay fever, mild flus, and other such things, and classify them as “colds.”