Dark year on the cholera front. With the alert triggered by Kenya, which announced sixty cases on October 19, thirty countries are now affected by an epidemic. That’s a lot more than the last five years. Less than twenty countries had on average reported an epidemic outbreak, recalls the World Health Organization (WHO).
Faced with the multiplication of outbreaks, the WHO is in need of vaccines. Certainly, production has increased since the creation of stocks for emergency distributions in 2013, but not enough. The 36 million doses scheduled for 2022 have proven ineffective, even though this oral vaccine is slow, easily administered, without the need for a cold chain.
A single dose of vaccine
The WHO therefore decided, on October 19, that a single dose would henceforth be administered, instead of the two recommended. “With two doses, the efficacy is 85% and the protection lasts three years. With just one, the effectiveness is around 60% and protects for less time, but it does reduce the spread,” explains John Johnson, vaccination adviser for Doctors Without Borders.
Because countries that had been exempt for a long time have seen the bacterium reappear Vibrio cholerae. Highly contagious, the bacillus is transmitted by faecal contamination of water and food and can cause cavitations, which are quickly fatal if they are not treated with antibiotics and rehydration. Thus Lebanon, without cases since 1993, sees the disease spread. Neighboring Syria, which had not had an outbreak since 2009, had 900 cases and 44 deaths on October 19.
Cholera thrives on conflict and climate disasters
Haiti sees with fear the bacillus returning, the same one that has now caused 10,000 deaths, and undoubtedly at least 30,000 victims, during the most terrible epidemics triggered after the earthquake of 2010, whose country has took more than eight years to get rid of. The 33 deaths, 115 confirmed cases and 964 suspects reported as of October 20 are certainly far below reality, with many areas of the country inaccessible due to insecurity.
“Conflicts or chronic crises create situations favorable to the epidemic, especially since countries are not equipped to respond to them”, explains John Johnson. Severe droughts and recorded floods are also conducive to the spread of the bacteria. “Cholera epidemics usually develop at the end of the dry season, when the concentration of faecal matter increases in the waters of rivers and lakes to a particularly low level. This is what is happening in Iraq, Somalia, Niger or Nigeria,” continues John Johnson.
Better for vaccines only from 2024
But floods also carry the bacteria, as in Pakistan and Mozambique. The situation considered particularly worrying in Malawi, where 25 of the 28 districts are affected. Over 5,000 cases and 147 deaths have been inferred. “If we don’t improve the conditions of hygiene and infrastructure, with the multiplication of extreme climatic episodes we will have more and more cases of cholera”, warns John Johnson.
On the vaccines front, no improvement is expected before 2024. The Indian subsidiary of Sanofi has planned to stop production of three million doses of Shanchol at the end of the year. All that remains is the 33 million doses of the EUvichol vaccine produced by the Korean EuBiologics. “A new vaccine is expected to be licensed by the WHO in 2024 and could eventually increase to 55 million doses,” says John Johnson.