Question about cold viruses: any GPs/virologists out there?

[CrapSuzette]

I have 3.5 year old twins. From what I've read, it seems there are around 200 cold/flu viruses out there - and right now it feels as though my two have had every single one of them! They are otherwise healthy, were born at term etc. But they have attended nursery for two days a week since they were one year old, and barely go for a week without coming down with something. The nursery is based at the hospital where my husband works, and I suspect the number of viruses going round has been much greater than if they went to a nursery that wasn't based in a hospital.
Anyway, my question is: when does immunity to viruses finally kick in? I think, realistically, that they've had upwards of 60 cold viruses each in the last 2.5 years, so surely they'd be immune to around 1 in 3 colds by now? Or doesn't it work like that, because each individual cold virus mutates? Does exposure to one cold virus mean immunity for life?
As you can tell, I'm getting desperate, because they actually seem to be getting more viruses the older they get. We've actually taken them out of the hospital nursery (just over a week ago), and they currently have what I suspect to be a really, really nasty RSV (probably a nice parting gift from the nursery). They are due to start preschool this month, and I am desperately hoping that they won't get as many bugs there (a. because there are far fewer children and b. because it's nowhere near a bloody hospital!).
Many thanks in advance.
PS apols for any dodgy spelling/grammar. Am very sleep deprived.

Poor you, hope your kids are well soon and you can get some sleep!

I read somewhere that in the first 2 years of life children have up to 50 infections a year. that is roughly one a week. but some of them only result in a snotty nose that "just doesn't go away".

I'm not a virologist, but I have pondered this, as mine were never well as preschoolers, from September to May. They were worse the the year I had a nanny, which I think is because nannies haul sick children round to each others' houses, because they don't want to sit at home on their own.

I did notice that it tailed off significantly when they went into juniors, so they must've had most things by then, and now they are at secondary, they are ill about the same amount as adults.

I think "colds" are a collection of viruses and they don't mutate as such (like flu does) but there are simply so many little subspecies that it's hard for our immune systems to keep up.

As I understand it, yes, exposure to one cold creates immunity, but there will be another one along next time that you're not immune to.

Are you sure it's a cold, and not eg an allergic reaction to something in their environment? I know as an adult you can tell the difference because there's that coldy feeling and everything tastes odd - they won't be able to communicate that at 3.5. (Having said that, I've always been able to tell when ds has a cold, but then, he isn't allergic to anything so I don't really know what that's like.)

It sounds so hard. I'm sure your gp would be happy to see you, though: maybe go in and see what he/she says about it?

Thank you so much for your responses! I don't think they're allergic to anything. Have spoken to our GP, who says that it's not an indicator of problems with their immunity; just of how many viruses children their age come into contact with.
I do wonder if things have been worse over the last year or so because their lives - and those of their peers - have become more 'social', with everyone attending more groups/mixing more with other children.
Guess I just have to ride it out! My GP said that it should set them up for when they start 'proper school,' and they'll get fewer bugs then. I keep clinging to that possibility, but it's soooooo soul-destroying in the meantime. Keep wondering if there's anything I should be doing differently, but they usually eat well, I give them multivitamins and don't know what else I can do, other than never take them out, which would be impossible.
Interesting about them having 50 infections a year! I often wonder if a 'bad' cold is actually 2/3 viruses hitting them at once. Has anyone had any luck with echinacea, by the way? Or would I just be wasting my money?

Don't know about echinacea (I thought it had been properly researched and no effect had been found, but I could be wrong.

I remember months of cold after cold (urgh, the snot!) and it's been much better even since ds started school last year, so take heart.

Thank you, Unprune! I think I'll save my money and just hope that taking them out of the hospital nursery and starting the much smaller preschool will mean fewer infections. Glad your DS is doing well - that's exactly what I wanted to hear!

I'm a microbiologist but bacteria are more my thing. But what Unprune said is right! I think the bad colds are just different types/sub-types that are associated with more severe symptoms. But I guess it could be one on top of another at times. I wonder also whether there might be more than 200 - I would imagine that's an estimate but there may be different subtypes that cause disease and haven't been isolated/tested for as they don't cause a severe enough disease to warrant investigation? Don't know....have to get a real virologist to answer that!

I think with twins as well it must feel like one long-never ending cold! I know with my DS2 last year it felt like I could count the days of the Winter when he wasn't coughing or sounding chesty! My DS1 is 5 and at Infant school and he doesn't get that many colds now - maybe 1-2 a season. My GP always said the same thing about better now than at school. Which I guess may be partly right and partly just as they get older maybe their immune systems are getting more mature and able to brush off things more efficiently.

(DH works partly in virus research, so I generally am aware of what makes a given virus interesting - but colds don't get his attention!)

Thanks, Zam72. You're right - with twins it does feel like one long cold, as they pass viruses between each other. But I guess it's the same in any family where there's more than one child - as you've clearly experienced!
I've also often wondered whether there are more than 200. Certainly feels that way. Interestingly, with this latest one DH and I have had a bit of a chesty cough, but have been nowhere near as poorly as the DTs. Which possibly means we've been in contact with this virus, or a similar incarnation to this virus, at some point before. My SIL also has it, however, and she's been really rough with it.
I suppose what I'm hoping to hear is that now the DTs have had this particular illness this season, it's unlikely they'll get it again (at least not this version, this year).
Hope all this makes sense... frantically trying to shove breakfast in my gob between wiping runny noses...
Thanks again for all responses! Almost weepily grateful that I'm not alone in this (I was starting to get paranoid).

I think the anecdotage is that Nursery babies are horribly diseased, but stay healthy when they go to School.

Stay At Home babies are fit and well until they go to school at which point they catch everything going.

THe main problem seems to be that you are allowed to pump chicks and piglets with large amounts of antibiotics when they go into their first communal barn, but you can't do that with small humans. Hence the humans get unavoidably sick when the congregate for the first time.

I've heard that too, Catinthehat! I think it's a case of going through the mill now, or when they're five. Although with the antibiotic and young animals thing: not sure how that works as I thought anti-bs don't work against viruses, only against bacterial infections. Thankfully, it doesn't look as this virus is heading towards a secondary infection... so I should be thankful for small mercies!
Anyway, things looking better here this afternoon. With any luck, they'll be back at preschool on Monday. It's rotten timing, as they had two settling-in days and did really well, but after a break of a week we'll be back to square one.
Thanks again for all responses.

I find it interesting that it takes a child between 5 and 7 years to have a fully developed immune system so children who have been breastfed have better developed immune systems than children who have not and if a child is breastfed upwards of 2 years, they have that increased protection and probably have a better chance of fighting infection than children who do not.

(This is not intended as a post FF/BF argument or to make anyone feel bad about how they have fed their child, it is just some facts that I have collected during my own personal research into the benefits of BFing. If everyone didn't have any other option WRT feeding and if everyone could BF then maybe childhood infections wouldn't be so prevalent?)

There's so much genetic variation in immune systems (this is well-researched) that the interplay between your genetic propensity to fight off viruses and the immunities transferred via breastmilk must be fiendish to tease out.

DGS is 2 and is still bf. He has never been to nursery and only meets up with other toddlers once a week. So far he is disgustingly healthy, couple on minor colds (2 days of snotty nose), one slight fever and never had D&V. My DD is dreading him starting nursery at 3 as expecting an avalanche of illnesses but what catinahat says is sooo true!

I look on it as generally a positive thing. The exposure to viruses through communal/societal activity as youngsters boosts & builds their immune system for the future. Because of that, in a kind of bizarre way, having less (minor) childhood infections isn't necessarily good, because it means they don't have immunity to those viruses. The immune system definitely thrives on stimulation. (In fact the so called "hygiene hypothesis" suggests that being over sanitary and limiting childhood exposure to infections has caused the rises in asthma and allergy and is supported by epidemiological data. en.wikipedia.org/wiki/Hygiene_hypothesis)

when I say positive - I should qualify I don't mean children suffering is positive! But we've been lucky in that DD, although she has had constant colds, coughs and sniffles through nursery, hasn't been horribly affected (high fevers. malaise etc) so it hasn't been too traumatic. My nephew who tends to be more "fevery" seems to suffer more badly when he has a cold than she does, so I don't mean to underestimate the suffering involved.

Just popped back on here - thanks for more responses! Sausagerole - I agree. I KNOW in my heart that mixing with other children and getting lots of viruses in toddlerhood does boost their immune systems for later (I think, too, that there was an interesting study done a few years back that suggested that children in day care had a significantly reduced risk of developing a type of childhood leukaemia).
Anyway... they are a little better today. Fingers crossed we're coming out of this one... only, no doubt, to have another one coming along within the next week or so!

fingers crossed that the next one will only be snotty noses :)

It must really feel never ending with twins though Suzette! I feel your pain!

Ah, thank you both! It does feel neverending, but there are benefits - double the (very snotty at the moment) kisses. Am just hoping they're getting the really big nasties out of the way so we have an illness-free Christmas for once clutches at straws