Antibiotics and vaccines

The return is enormous and the chemistry is modest. In order of reach:

• Smallpox, eradicated in 1980, needed only cowpox material and a lancet — and remains the template for the rest.
• Killed and attenuated vaccines — rabies, typhoid, cholera, plague — need culture, careful inactivation and honest quality control, but no exotic synthesis. Growing the organism, killing it with heat or formalin, and proving every batch is dead before it goes into a person is the whole discipline.
• Toxoid vaccines — tetanus and diphtheria — are among the highest-value of all, because tetanus is otherwise untreatable at any tier below this one.

Test every batch for sterility and potency, keep a sample of each, and number the batches so a bad one can be traced and withdrawn.

A vaccine that has been warm is an inert liquid that gives false confidence — worse than no vaccine, because nobody looks for the disease.

Build first — see refrigeration and the cold chain: storage at 2–8 °C with reliable power from the generator or a flame-driven absorption unit, an ice-lined cabinet that holds temperature through an outage, a thermometer read and written down twice a day, insulated carriers with ice packs for transport, and a rule that a break in the chain discards the stock. Know which vaccines freezing destroys — toxoids and anything adjuvanted are ruined by freezing, so "colder is safer" is wrong. Discard on the record, not on judgement.

Sulphonamides are chemically synthesised rather than grown, which puts them within reach of a tier-4 chemical industry — no fermentation, no unstable molecule, no purification of a natural product. They were the first effective systemic antibacterials and saved a great many lives before penicillin existed.

They work by blocking bacterial folate synthesis, which is why they touch bacteria and not us. They are not harmless: crystals in the kidney if the patient is not kept well hydrated, and severe skin and marrow reactions in a minority. Dose properly, push fluids, and stop at the first rash.

Isolating a producing Penicillium strain is plausible. Everything after that is an industrial problem of real difficulty, and it is worth being honest about the scale: it took a wartime effort across many organisations to go from laboratory curiosity to usable drug.

The hard parts, in order: deep tank fermentation with sterile aeration and agitation; a medium that pushes yield; extraction of a molecule that destroys itself in acid, in alkali and in heat, which means solvent extraction at low temperature and speed at every step; and assay, because you cannot dose what you cannot measure. Expect the first batches to be weak and variable, and dose by assayed potency rather than by volume.

A contaminated fermenter is a wasted month, and contamination is the normal outcome until the technique is ruthless.

Autoclave everything at 121 °C for 15 minutes, longer for volumes. Sterilise the medium in the vessel, not before it goes in. Filter the air supply, and keep the vessel at slight positive pressure so leaks blow out rather than in. Transfer with flamed loops in still air, moving nothing over an open vessel. Culture a sample from every batch on day one and watch it — knowing on day two that a run is contaminated saves the other twenty-nine days. Write a contamination rate down and drive it toward zero.

This is a resource that can be permanently destroyed by misuse, and the world this site came from was in the process of doing exactly that. Resistance appeared in clinical use within a few years of both sulphonamides and penicillin, and it spreads between species of bacteria on plasmids.

The rules, in force from the first dose: full courses, never partial; no agricultural growth promotion, ever — farm use has taken the majority of antibiotic tonnage in many countries and bred resistance in the animals people eat; no treatment of viral illness; narrowest effective drug, not the strongest; and a written record of what was given for what, reviewed for drift. Keep one drug in reserve and do not use it routinely.

Clean water, sanitation, nutrition and vaccination still prevent far more disease than antibiotics cure, and they keep working when the drug supply fails — which it will, periodically, at every tier.

The test is budgetary, not rhetorical: if the antibiotic programme is funded while city water and sewerage is unfinished, the allocation is wrong. Antibiotics are what you have because prevention is imperfect, not instead of it.