further 3,240 doses arrived three days later; with another 8,000 doses to be made available. the vaccine must be transported and stored at between −60 and −80 °c. a cold chain was established in kinshasa by 18 may and has been extended to mbandaka. who planned to concentrate on vaccinating three sets of contacts of confirmed evd cases, two in bikoro and one in mbandaka. vaccination started on 21 may among health workers in mbandaka, with 7,560 vaccine doses ready for immediate use, according to who. the drc health minister oly ilunga kalenga stated that vaccination of health workers and ebola case contacts in the wangata and bolenge areas of mbandaka would take five days, after which vaccination would start in bikoro and iboko. as of 24 may 2018, 154 people in mbandaka had been vaccinated, and preparations were started for vaccinating in bikoro and iboko. up to 1,000 people were expected to have been vaccinated by 26 may, according to who. it was the first time that vaccination had been attempted in the early stages of an ebola outbreak. the rvsv-zebov vaccine proved effective for the strain of the ebola virus in this outbreak, having via ring vaccination protected some 3,481 individuals. experimental therapeutic agents further information: ebola virus disease treatment research chemical formula of favipiravir health officials considered trialing experimental treatments, including the antiviral agents favipiravir and gs-5734, and the antibody zmapp. all three agents were given to patients during the west african epidemic, but none has yet been proved to be effective. the drc ministry of public health also requested that the us trial mab114 treatment during the outbreak. the mab114 monoclonal antibody was developed by the national institutes of health and jean-jacques muyembe at the national institute for biomedical research, and is derived from an evd survivor of the 1995 kikwit outbreak who still had circulating anti-ebola antibodies eleven years later; it has been tested in macaques but not in humans. the zmapp cocktail was assessed by the world health organization for emergency use under the meuri ethical protocol. the panel agreed that "the benefits of zmapp outweigh its risks" while noting that it presented logistical challenges, particularly that of requiring a cold chain for distribution and storage. despite being at earlier stages of development, three other therapies, mab114, remdesivir and regn3470-3471-3479, were also approved for emergency use under meuri and the ministry of health in the drc. prognosis further information: post-ebola virus syndrome post-ebola virus syndrome affects those who have survived evd infection; the resulting signs and symptoms can include muscle pain, eye problems and neurological problems. history further information: list of ebola outbreaks the democratic republic of the congo (formerly zaire) has had several previous evd outbreaks since 1976, which are summarised in the table below. all have been located in the west or north of the country. three previous outbreaks (in 1976, 1977 and 2014) occurring in former province of équateur, of which the current équateur province forms part. in 2014, the who considered that the drc was lagging behind the rest of africa in health expenditures, at the relative rate of intl$32 per head. for the 2017 democratic republic of the congo ebola virus outbreak, the drc regulatory authorities approved the use of the experimental rvsv-zebov vaccine, but logistical issues delayed its implementation until the outbreak was already under control. shortly before the first cases of the 2018 ebola outbreak, the country experienced a widespread cholera epidemic (june 2017 – spring 2018), which was the most serious in the country since 1994. timeline of ebola outbreaks in the democratic republic of the congo (formerly zaire) since 1976 v・tdatecountrymajor locationoutbreak informationsource straincasesdeathscfr aug 1976zaireyambukuebov31828088% jun 1977zairetandalaebov11100% may–jul 1995zairekikwitebov31525481% aug–nov 2007democratic republic of the congokasai-occidentalebov26418771% dec 2008–feb 2009democratic republic of the congokasai-occidentalebov321445% jun–nov 2012democratic republic of the congoorientalebdbv773647% aug–nov 2014democratic republic of the congotshuapaebov664974% may–jul 2017democratic republic of the congolikatiebov8450% apr–jul 2018democratic republic of the congoéquateur provinceebov543361% aug 2018–june 2020democratic republic of the congokivuebov3,4702,28066% june–nov 2020democratic republic of the congoéquateur provinceebov1305542% feb 2021–may 2021democratic republic of the congonorth kivuebov12650% april 2022democratic republic of the congoéquateur provinceebov55100% august 2022democratic republic of the congonorth kivuebov11100%