[dorfsmay]

Vaccination is using deactivated viruses. My question is can we get the same effect from exposure to small doses of live viruses.

The articles says exposure to tiny amount can "boost" immunity, which I assume means an immunity acquired earlier from a full blown infection (or vaccination).

[southernplaces7]

As with many things in medicine, it depends on specifics and context. With some viruses, this might work, and with others it could kill you. Vaccination itself is tricky partly for this very reason as far as I know (not a doctor or epidemiologist).

Variolation for example, the predecessor to the world's first practice of vaccination (against smallpox) involved taking tiny amounts of live smallpox from scabs or pustules and giving them to people intentionally for a much lighter infection course that made them immune without the usually killing or horrifically disfiguring blow of a full smallpox infection. (look up photos of smallpox scars in survivors, warning, it gets graphic. Even many famous figures like Stalin were completely pockmarked by the scars of the virus for the rest of their lives, as you can see in unedited photos of the dictator)

It usually worked, but sometimes the patients got really sick anyhow and died. By the standards of the time, when fully a third of the population could expect to die from some epidemic disease or another, this was considered wonderful. Today it wouldn't be and thus the complexities of carefully calibrating vaccines.

[cutemonster]

Interesting!

I suppose one more dangerous thing with this, could be how popular anti vaccination ideas could become, when the anti-vaxxers start saying that vaccine is live virus

[southernplaces7]

My variolation example above was only a very specific, very antique context of something that did involve live virus but wasn't considered true vaccination as we use it today. However, even today the basic reality is that some vaccines do involve live viruses or other pathogens in a weakened state. This doesn't make them dangerous in any general sense.

And that live pathogens are sometimes used should be known and discussed for the sake of clinical honesty and public health transparency. Either way, for any deeply dedicated anti-vaxxer, it probably wouldn't matter what they hear from even the best source. Once one's fixation on a concept becomes emotional or ideological, the subtleties and details of explaining contrary details stop mattering to them.

[ABCLAW]

Vaccination generally uses an adjuvant to increase immune response to the target antigen in order to provoke a response strong enough to produce lasting immunogenic memory. Antigens alone in small numbers aren't enough.

Taking random adjuvants consistently after minimal exposure to environmental antigens is more likely to give you deleterious allergies or issues associated with chronic inflammation.

[maxerickson]

Vaccines are rooted in a history of doing exactly what you are talking about. Smallpox variolation was done for hundreds of years before the development of the first vaccine.

https://www.cdc.gov/smallpox/history/history.html

[malfist]

Vaccination can use deactivated viruses, but not always.