Cholera: WHO suspends two-dose strategy amid vaccine shortage

The World Health Organisation (WHO) says the International Coordinating Group (ICG) — the body which manages emergency supplies of vaccines — has temporarily suspended the two-dose cholera vaccination regime due to a strained supply of vaccines.

In a statement on Wednesday, the organisation said the ICG will instead use a single-dose approach.  

While noting that there has been an “unprecedented rise” in cholera outbreaks worldwide, the WHO said the pivot in strategy will allow for the doses to be used in more countries.

“Since January this year, 29 countries have reported cholera cases, including Haiti, Malawi and Syria which are facing large outbreaks. In comparison, in the previous 5 years, fewer than 20 countries on average reported outbreaks. 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 reads.

“The one-dose strategy has proven to be effective to respond to outbreaks, even though evidence on the exact duration of protection is limited, and protection appears to be much lower in children. With a two-dose regimen, when the second dose is administrated within 6 months of the first, immunity against infection lasts for 3 years.”

The WHO said while the temporary interruption of the two-dose strategy will lead to a reduction and shortening of immunity, it will allow more people to be vaccinated and provide them protection, should the global cholera situation continue deteriorating.

“The current supply of cholera vaccines is extremely limited. As vaccine manufacturers are producing at their maximum current capacity, there is no short-term solution to increase production. The temporary suspension of the two-dose strategy will allow the remaining doses to be redirected for any needs for the rest of the year,” the WHO said.

The ICG is expected to continue to monitor the global epidemiological trends as well as the status of the cholera vaccine stockpile.

According to the Nigeria Centre for Disease Control (NCDC), 10,745 suspected cases of cholera and 256 deaths have been recorded in Nigeria within 10 months.

The agency said it is monitoring the epidemiological trend to guide its request to the ICG for planned vaccination campaigns.