Seventeen new infections and 11 new fatalities raise outbreak totals to 2,025 cases and 1,357 deaths.
The groups welcomed new commitments to humanitarian aid, but said a response reset is needed.
An ethics committee fine-tuned an earlier vaccine recommendation, clearing its use in pregnant women past their first trimester and lactating women.
The death rate in infected preschoolers is 77%, compared with 57% for other Ebola patients.
Experts say the outbreak likely began as far back as April 2018 and that nosocomial transmission played a big role in early spread.
The WHO warns that a decline in the rate of cases should be interpreted with extreme caution.
In the past 5 months, the WHO has recorded 174 attacks on clinics and health workers, killing 5 and injuring 51.
The outbreak total grew by 11 cases today, reaching a total of 1,888 infections.
"An enhanced UN-wide response is required. . . . We have no time to lose," says David Gressly.
The 19 new infections raise the outbreak total to 1,866 cases amid continued threats.
