Hygiene hypothesis vs exposure to viruses such as covid 19

[TurquoiseBeach]

I've seen the view that it's somehow good to expose children to covid to build up their immune systems. It never quite made sense to me (we don't rush to expose them to other viruses that we know harm them). This thread explains quite well how exposure to friendly microbes can be good, but shouldn't be applied to exposure to things like covid.

twitter.com/lisa_iannattone/status/1581372711506677761?s=46&t=h0nFnzMNhWRwqZVRVftpLQ

@TurquoiseBeach

My understanding is that - the vaccine triggers an immune response in a safe way - and gives longer lasting/better protection. A mild natural immune response may wane quickly/not last long.

Sorry, I didn't mean from vaccine - I meant people that argue for natural exposure, saying it's a good thing.

I don't think we rush to expose people to covid it just happens as a byproduct of living, much like exposure to every other virus?
We used to have measles parties and prior to the introduction of a chicken pox vaccine didn't worry too much about chicken pox, though can see us getting more risk averse towards that now, but I've never heard of people doing the same with covid.

Anyhow all that said, I've spent a fun half hour googling microbiome wrt covid and discover little gems like

"A systematic review conducted on 41 studies indicated that pre-existing Mycobacterium tuberculosis is associated with the risk of lung cancer"

"Make-up of gut microbiome may influence COVID-19 severity and immune response"

and I'm aware of the link between Epstein Barr virus and long glandular fever
And strep and PANDAS.

So, since changing the environment seems to be not happening, do we look at what we can do for the terrain?

I think its misleading to use the term "good", its rather that it's the reality of being a human & normal human development, it's all about timings and balance - neither too many germs or too few as problems arise both with a naive immune system (and many adults died precisely because we had not encountered Covid in our lives) and with an over-active immune system (auto-immune diseases for eg.) So for example, you really don't want your baby to be exposed to polio,measles ,mumps etc before they get their jabs but equally catching chicken pox, cytomegalovirus etc from toddlerhood onwards is better than catching it as an adult. RSV spread is the most obvious one that's been impacted by children being protected from covid so there have been much higher numbers of kids being admitted to hospital then normal plus the normal "seasonality" and age ranges of certain bugs have changed - my friends 2 teenagers both got slapped cheek last year for eg.,1was really poorly, and this is a parvovirus that normally you see in younger kids.

In reality, normal life exposes children to an array of viruses and bacterial infections and their immune systems usually rise to the challenge with little lasting effect.

Younger children are often more ill for a while when introduced to environments like nursery/ school for the first time before they adapt.

My children haven't been vaccinated from Covid. DS2 had several exposures before he had a positive LFT when I had Covid. His symptoms were very mild to the point that had it not been December 2021, I wouldn't have considered him "ill". He then had a Covid positive "cold" and we used the enforced time off school to go on bike rides and country walks. His immune system seems to have caught up to the job naturally.

DS1 had never tested positive despite 3 sets of household cases (we live as normal). He may have had it just after starting secondary school in September, but given that he was coldy/ fluey ill off school anyway, testing the brand of illness was a moot point. He may possibly have had it in December 2019 and some unpleasant respiritory illness hit the class then. That made him ill for over a week, put him on functional energy for about 3 further weeks, and another 2-3 months before being back on full power and it did correlate with the subesquent emergence of the first form of Covid 19, but nothing can be proven.

The vast majority of children were statistically highly unlikely to be seriously unwell unless there were known risks, and most just have a normal range of illness, and their immune systems are used to adapting to varied stimulai.

Having children prone to allergies/ asthma/ eczema I have never tried to strictly santise their environment and would rather their immune system works on normal pathogens than develop exaggerated responses to things like food and everyday products.

Depends on the virus. Chicken pox is good to get out the way when young and gives life-long protection so I wouldn't try to avoid it. Noro, for example, there's no lasting immunity. They're sick as a dog and miserable with no real benefit so I try to avoid that where possible. Some viruses trigger autoimmune diseases and cancers and who knows what damage covid might do long term (heart disease and altzheimers have been suggested).

I think its good to observe basic levels of hygiene, open a window occasionally and wash our hands after the toilet without it having to overtake our lives.

The hygiene hypothesis basically relates to microbes you ingest eg playing in dirt is good, builds your immunity against allergies etc. Contracting lots of colds and respiratory infections is NOT beneficial, they don't confer immunity. The immune system is not a muscle to be strengthened through constant exposure to viral pathogens.

The FT had a good piece on why the immunity debt theory is dangerous www.ft.com/content/0640004d-cc15-481e-90ce-572328305798