The World Health Organization (WHO) said on Wednesday it will temporarily shift to a one-dose strategy from the standard two-dose vaccination regimen for cholera due to vaccine shortages and rising outbreaks worldwide. 

"The pivot in strategy will allow for the doses to be used in more countries, at a time of unprecedented rise in cholera outbreaks worldwide," WHO said in a statement on Wednesday.

The statement highlighted that 29 countries had reported cholera cases in 2022, with Haiti, Syria and Malawi fighting large outbreaks of the deadly disease.

Currently, Haiti has confirmed at least 32 cases and 18 deaths from cholera.

"The global trend is moving towards more numerous, more widespread and more severe outbreaks, due to floods, droughts, conflict, population movements and other factors that limit access to clean water and raise the risk of cholera outbreaks," the statement highlighted.

Is one dose enough?

Cholera is an acute diarrheal infection caused by bacteria found in contaminated water. The disease affects millions worldwide every year.

In the previous five years, fewer than 20 nations had reported such outbreaks in total. 

The WHO said that a one-dose strategy for cholera vaccines had been proven to be effective in response to outbreaks, even though the duration of protection might be lower than with the standard two-dose vaccination, especially in children. 

With two doses, immunity against infection can last for three years if the second dose is given within six months of the first. 

"The benefit of supplying one dose still outweighs no doses," the statement said.

"Although the temporary interruption of the two-dose strategy will lead to a reduction and shortening of immunity, this decision will allow more people to be vaccinated and provide them protection in the near term, should the global cholera situation continue deteriorating," it added. 

los/wmr (AFP, Reuters)