Doses of cholera vaccine are being given to patients as fast as they are produced and the global stockpile has run completely dry, as deadly outbreaks of the disease continue to spread.

This does not shock anyone in the field of emergency epidemic response because the vaccine stockpile has been precariously low for years.

The surprise — the good news, which is in itself surprising since ‘cholera’ and ‘good news’ are rarely used together — is that three new vaccine makers are setting up production lines and joining the effort to replenish the stockpile. And a fourth company, the only one that makes the vaccine which is given orally, has been working at a pace that experts describe as “heroic” to expand its production.

Yet even with all this, the total global supply of the vaccine that will become available this year will be, at best, a quarter of what is needed.

At the end of February, countries had already reported 79,300 cases and 1,100 deaths from cholera this year. Since there is no uniform system for counting cases, this is most likely a gross underestimate.

In October 2022, the organisation that manages the global emergency cholera vaccine stockpile made an unprecedented recommendation that people receive only one dose of the vaccine instead of two to stretch the supply. A single dose of the cholera vaccine provides between six months and two years of immunity, while the full regimen of two doses delivered a month apart gives adults roughly four years of protection.

Last year, countries sent requests for 76 million doses of the vaccine for single-dose “reactive campaigns” — efforts to vaccinate people in places with active outbreaks.

There were only 38 million doses in the stockpile, so only half the requests were filled, and those were with only a single dose. No vaccines were left for preventive campaigns that would ideally be carried out in places such as the Gaza Strip, where all of the conditions for large outbreaks exist, or in places where cholera is endemic.

The race to make more cholera vaccine illustrates all of the reasons it’s so hard to respond to epidemics even with the participation of committed drugmakers who are not scared off by the slim profit margins in an immunisation that’s mostly for poor people.

Cholera can cause death by dehydration in as little as a single day as the body tries to expel virulent bacteria in streams of vomit and watery diarrhoea.

The disease is spread through unclean drinking water. The current outbreaks are being driven by the spread of conflict and climate disasters that force people into crowded living situations without adequate sanitation systems. In recent months, there have been outbreaks in 17 countries.

New York Times News Service