KINSHASA, Congo (AP) — The head of Congo's Ebola response says another vaccine will be used to fight the outbreak that has killed more than 1,800 people in a year.

Dr. Jean-Jaques Muyembe is the director of Congo's National Institute for Biomedical Research. He said Monday the World Health Organization has recommended the use of a preventative vaccine manufactured by Johnson & Johnson.

Muyembe also promised to put an end to the Ebola outbreak in the next four months.

Health officials have already vaccinated more than 197,000 people.

USAID head Mark Green visited Congo on Monday and promised that the organization and others will continue to work to end Ebola and invest in medicines and community development.

Response efforts have been hampered by attacks on health workers and continuing mistrust among the affected communities.