How to survive a bio epidemic?

Question

I'm a Father. Through the love that we share, I protect my children, show them how to fight. There was time when we don't have to fight, but the Stupi wants our Lovestones for his so-called 'industry'. So.

It was the fifth year of the world. Their attacks is less and less frequent. Maybe he is losing interest in killing us. I feel less my children dead from the their skirmish. But things are not getting better. A strange disease is spreading.

It started at the borders, no doubt from some evil scheme the Stupi had thought of. My children showed no apparent symptoms that the Mothers could do about. They just suddenly turned ill in a few days and then their love winked out. The Hight Father knew about this, but he had not thought of way to stop it, yet.

Feeling the love of my children winked out all over the Land, I wanted to freak out, but couldn't - thank to the Mothers. I suspect most of us had been infected, but I'm not sure. Are we all doomed? O Spirits! Show us the way to salvation! How do I protect my children from this?

Notes:

1. The only enemy we have is no the south: the Stupi
2. The rate of winking out is increasing, maybe we have a year, or a month
3. We only have 150 000 Brothers fit for fighting, spreading all the border to maintain the illusion of the invincible army
4. The population is gathering at 13 Great Altars around the country.
5. On the north is the great winter land, we don't know what's up there, we hadn't needed to ventured there before
6. Our people live with nature, resources were plentiful, we don't make anything new, if the old still serve us well enough (my cloths were of my great grand..)
7. I have no illusion of getting out of this the easy way, saving even one of the Altar is good enough
8. The Lovestones were the manifestation of our deceased ones's love, there's nothing magical about it, but we're not giving it away

Edit 1:

1. Father is a title of a leader (equivalent of a lord), High Father is the king
2. Mother is a title of a psychic healer, their only purpose is to maintain the positive emotional atmosphere
3. Lovestones offer no magical power, they slowly crystallized from nothing where someone (of that race) died.

Third person perspective: The Wussname is a close people. They're not very friendly to strangers. Everything about them is pretty much ambiguous, plenty of rumors, nobody sure. The Stupi thought the Lovestones are the source of their psychic power, so obviously his Evilness wants it. The Stupi tried many kind tactics against them but couldn't make a noticeable victory in decades. One day, he forced villagers (infected with a terrible disease that is well known in his country) to take up arms and march into the Wussname. Then he quarantine his borders, shoot anything that try to cross and at the same time, lied to his men to continue the attacks as usual to pretend that he had nothing to do with spreading the disease (he had good public image).

Answer 1

Well, first thing's first: If you're being subjected to some bio-warfare attack in the form of a contagious disease, the worst thing you could possibly do is get the entire population to congregate - all that will do is increase the contagion rate, not to mention increasing squalor as a higher population packs into a small area and puts stress on the local services.

Secondly, I'm assuming running away isn't an option (fleeing to the northern lands where presumably there's something interesting (or you all die from the cold because noone has any thermals that their great grandparents used when they went on skiing holidays)), because that would leave the Great Alters/Lovestones unguarded. Are they portable? How does all that work? I'm assuming therefore that "stand and fight" is pretty much the only option.

Thirdly, the difference between surviving a natural plague (The Black Death, for instance) is pretty minimal, with one critical difference that I'll get to. To survive it, you either

1. Engineer/Find a vaccine
2. Steal a vaccine
3. Bank on the immune system being able to develop a resistance within a sufficient portion of the population
4. Mercilessly quarantine anyone who is even potentially infected and hope to starve it out.

As for the viability of each:

1. Only works if your civilisation is advanced enough in biology to be able to effect a cure quickly. I'm assuming not, given that you create nothing new. It also depends on the history of the Civilisation. You may not use anything new, but someone had to create it at some point. Was there a cataclysmic event in the past which caused your current society? Might they have had the biological expertise to have dealt with this? Might there be some remnants nearby that you don't know about (like in those mysterious Northern Lands)?

2. Probably the best from a storyline perspective as it provides a good reason for protagonists to journey to the other civilisation, allowing you to develop that part of the world. Probably also the most viable solution as you would assume that if this was an engineered weapon, the Stupi would want a safeguard to ensure that it didn't backfire. If they don't have one, well, you can always spread the pain and prevent further attacks (I'll get to this).

3. This is pretty boring from a story perspective and also depends on the "success rate" of the disease. If it is fatal 100% of the time (or really anything over 75% or so) the overall devastation to the population before widespread natural immunity kicked in would be crippling. Even smallpox only had a mortality rate of ~35%, the black death killed 30%-60% of Europe, depending on the data you look at. Anything over 50% and the effects on the population would be brutally obvious and nothing would stop the Stupi from invading, which presumably is endgame and not what you want.

4. Again, this depends the disease. How contagious is it? How widespread is it? If a critical proportion of the population already have it then there's no point in even trying. This would only work if say <10% already had it and the mortality rate was high - the "cost" of effectively killing 10% would outweigh the ultimate loss of life should everyone get infected.

Finally, it's worth considering the critical difference between a manufactured bio-attack and a naturally occurring epidemic - If this one proves a decent weapon that was only just prevented, they'll probably just make another one and send that in on its coattails. To provide an endgame you have to construct a solution that will prevent any future attacks, so that pretty much discounts options 3 and 4. It would add complexity to 2. as they would need to also find a way of neutralising further attempts. Option 1 might offer something on that front, but it would have to be successful enough that it gave the impression to the Stupi that developing cures was easy and you could do it again without issue, to discourage them from using the same method again. Chances are the best approach is a mixture of Options 1 and 2.

Where has it come from? Find that out from within the Stupi. Did they just find it? Is it a relic of the past? Maybe there is an answer in the Northern wastes? Clearly you're open to this as you don't just drop a "we've never had reason to go there" and just leave it :P

Finally, If you only have a month, you're screwed. Nothing you can do, just say goodbye to everyone you care about. There is literally no way you can knock something up in that time (and presumably it'd take longer than two weeks to travel to the Stupi capitol where they might have a vaccine), so without some ridiculous plot device where someone/thing magically appears to save you, you've got no hope.

Even a year is stretching it a bit. Given that "finding a cure" seems the only approach, that's going to take at least a few months or travel/investigation otherwise it's a pretty damn short story. If everyone's dead in a year, 50% are dead in 6 months, assuming a linear timeframe. You say that "One alter surviving is enough", but let's be honest here - one out of 15 means that less than 7% of the population survived. Noone is going to recover from that, and you'll never be able to keep up the pretence of an invincible army to keep the Stupi out.

Ultimately the timeframe is unimportant because the only way you're going to get out of this is stealing/acquiring a cure or uncovering some latent, immediately effective ability (maybe something to do with the lovestones? How's that work anyway? Maybe there's something about the way they're made that could help you). Given that, it's just a matter of fitting the acquisition method to the arbitrary timeframe you've laid down for yourself...