Not sure if it perfectly fits your criteria, but you could find it interestingly related anyway.

In the 1887^* illustrated sci-fi story La Guerre au 20ème siècle ("War in the 20th Century") by Albert Robida, an unidentified army tries to use land mines and shells loaded with various diseases against the French army. All of this is designed by doctors, chemists, and engineers.

However, the French destroy the "miasma reservoir" where the diseases are stored, before the mines and shells are used against them. As a consequence, the diseases leak and spread among the enemy. The mix of diseases creates a new, unknown disease called the "fièvre molineuse", certainly killing thousands of civilians and soldiers (but sparing the French).

At the end of the chapter, it is mentioned that doctors across Europe "grow" this new disease – to weaponize it I'd assume, as medical ethics does not seem to be a concern in this fictional universe.

Below is an illustration from the book, representing the inside of a fortified place where doctors, chemists, and engineers develop their biological warfare plan. We see a sort of small lab on the right, and some tanks just under the large cannon, labelled with various disease names, including measles, dysentery, typhus, and smallpox (later, the text mentions additional diseases like yellow fever and... odontalgia):

Here is an illustration of the "réservoir à miasmes". In front of it, there are some doctors and engineers, manipulating a couple of flasks or vials:

And here is an illustration of the reservoir leaking after the French attack, with some smoke or vapor escaping from it, possibly some liquid too:

It seems there's a 1998 translation of the story in English, but I couldn't find it online. You can find the original story in French on Gallica at the following address, with higher resolution images than those I shared above: https://gallica.bnf.fr/ark:/12148/bpt6k3120885 . The chapter where the weaponized diseases appear is pp.16-20.

^* The Wikipedia article on this story mentions 1883 as a first publication date, but I did not verify the information. On the other hand, Gallica mentions 1887.

Not sure if it perfectly fits your criteria, but you could find it interestingly related anyway.

In the 1887^* illustrated sci-fi story La Guerre au 20ème siècle ("War in the 20th Century") by Albert Robida, an unidentified army tries to use land mines and shells loaded with various diseases against the French army. All of this is designed by doctors, chemists, and engineers.

However, the French destroy the "miasma reservoir" where the diseases are stored, before the mines and shells are used against them. As a consequence, the diseases leak and spread among the enemy. The mix of diseases creates a new, unknown disease called the "fièvre molineuse", certainly^† killing thousands of civilians and soldiers (but sparing the French).

At the end of the chapter, it is mentioned that doctors across Europe "grow" this new disease – to weaponize it I'd assume, as medical ethics does not seem to be a concern in this fictional universe.

Below is an illustration from the book, representing the inside of a fortified place where doctors, chemists, and engineers develop their biological warfare plan. We see a sort of small lab on the right, and some tanks just under the large cannon, labelled with various disease names, including measles, dysentery, typhus, and smallpox (later, the text mentions additional diseases like yellow fever and... odontalgia):

Here is an illustration of the "réservoir à miasmes". In front of it, there are some doctors and engineers, manipulating a couple of flasks or vials:

And here is an illustration of the reservoir leaking after the French attack, with some smoke or vapor escaping from it, possibly some liquid too:

It seems there's a 1998 translation of the story in English, but I couldn't find it online. You can find the original story in French on Gallica at the following address, with higher resolution images than those I shared above: https://gallica.bnf.fr/ark:/12148/bpt6k3120885 . The chapter where the weaponized diseases appear is pp.16-20.

^* The Wikipedia article on this story mentions 1883 as a first publication date, but I did not verify the information. On the other hand, Gallica mentions 1887.

^†After re-reading the story, it seems that the author never explicitly states that people are dying from the diseases, he just mentions incapacitating the enemy immediately, and sending over 170,000 people in hospitals. However, given the fatality rate of the weaponized diseases (smallpox, typhus, yellow fever, etc.), undoubtfully a large proportion of people ending up in hospitals would die. The book is intended to be light-hearted and humorous, which could explain why the author seems to omit this question.

Not sure if it perfectly fits your criteria, but you could find it interestingly related.

In the 1887^* illustrated sci-fi story La Guerre au 20ème siècle ("War in the 20th Century") by Albert Robida, an (unidentified) army tries to use land mines and shells loaded with various diseases against the French army. All of this is designed by doctors and engineers.

However, the French destroy the "miasma reservoir" where the diseases are stored, before the mines and shells are used against them. As a consequence, the diseases leak and spread among the enemy. The mix of diseases creates a new, unknown disease called the "fièvre molineuse", killing thousands of civilians and soldiers (but sparing the French).

At the end of the chapter, it is mentioned that doctors across Europe "grow" this new disease – to weaponize it I'd assume, as medical ethics does not seem to be a concern in this fictional universe.

Here is an illustration of the "réservoir à miasmes", with presumably the doctors and engineers who designed it:

And here's an illustration of the reservoir leaking after the French attack, with some smoke or vapor escaping from it, possibly some liquid too:

It seems there's a 1998 translation of the story in English, but I couldn't find it online. You can find the original story in French on Gallica at the following address: https://gallica.bnf.fr/ark:/12148/bpt6k3120885 (the chapter where the weaponized diseases appear is pp.16-20).

^* The Wikipedia article on this story mentions 1883 as a first publication date, but I did not verify the information; on the other hand, Gallica mentions 1887.

Not sure if it perfectly fits your criteria, but you could find it interestingly related anyway.

In the 1887^* illustrated sci-fi story La Guerre au 20ème siècle ("War in the 20th Century") by Albert Robida, an unidentified army tries to use land mines and shells loaded with various diseases against the French army. All of this is designed by doctors, chemists, and engineers.

However, the French destroy the "miasma reservoir" where the diseases are stored, before the mines and shells are used against them. As a consequence, the diseases leak and spread among the enemy. The mix of diseases creates a new, unknown disease called the "fièvre molineuse", certainly killing thousands of civilians and soldiers (but sparing the French).

At the end of the chapter, it is mentioned that doctors across Europe "grow" this new disease – to weaponize it I'd assume, as medical ethics does not seem to be a concern in this fictional universe.

Below is an illustration from the book, representing the inside of a fortified place where doctors, chemists, and engineers develop their biological warfare plan. We see a sort of small lab on the right, and some tanks just under the large cannon, labelled with various disease names, including measles, dysentery, typhus, and smallpox (later, the text mentions additional diseases like yellow fever and... odontalgia):

Here is an illustration of the "réservoir à miasmes". In front of it, there are some doctors and engineers, manipulating a couple of flasks or vials:

And here is an illustration of the reservoir leaking after the French attack, with some smoke or vapor escaping from it, possibly some liquid too:

It seems there's a 1998 translation of the story in English, but I couldn't find it online. You can find the original story in French on Gallica at the following address, with higher resolution images than those I shared above: https://gallica.bnf.fr/ark:/12148/bpt6k3120885 . The chapter where the weaponized diseases appear is pp.16-20.

^* The Wikipedia article on this story mentions 1883 as a first publication date, but I did not verify the information. On the other hand, Gallica mentions 1887.