The organisation said the patients would be evacuated on Wednesday in a rare transfer out of the war-ravaged enclave.
According to the statement, over 16 million girls in Nigeria alone could be protected with the injections by 2025.
The disease is more common in tropical and subtropical climates. Its incidence has grown dramatically worldwide in recent decades.
According to the WHO, this is the fifth time the facility has been hit since the violence in Las Anod erupted in 2022.
Bayelsa flagged off the third round of COVID-19 vaccination in Yenagoa.
