[8][9][10] Around half the people given the vaccine have mild to moderate adverse effects that include headache, fatigue, and muscle pain.

[10] Nearly 800 people were ring vaccinated on an emergency basis with VSV-EBOV when another Ebola outbreak occurred in Guinea in March 2016.

[19] In 2017, in the face of a new outbreak of Ebola in the Democratic Republic of the Congo, the Ministry of Health approved the vaccine's emergency use,[20][21] but it was not immediately deployed.

[9][10] Systemic side effects include headache, feverishness, fatigue, joint and muscle pain, nausea, arthritis, rash, and abnormal sweating.

[32][16] In 2010, PHAC licensed the intellectual property on the vaccine to a small U.S. company called Bioprotection Systems, which was a subsidiary of Newlink Genetics, for US $205,000 and "low single-digit percentage" royalties.

[37][38] In October 2014, Newlink had no vaccine in production and no human trials underway, and there were calls for the Canadian government to cancel the contract.

[33] In September or October 2014, Newlink formed a steering committee among the interested parties, including PHAC, the NIH, and the WHO, to plan the clinical development of the vaccine.

[39][40] In October 2014, Newlink Genetics began a Phase I clinical trial of rVSV-ZEBOV on healthy human subjects to evaluate the immune response, identify any side effects and determine the appropriate dosage.

As of that date, Merck had submitted an application to the World Health Organization (WHO) through their Emergency Use Assessment and Listing (EUAL) program to allow for use of the vaccine in the case of another epidemic.

[9][10] In September 2019, the US Food and Drug Administration (FDA) accepted Merck's Biologics License Application and granted priority review for the vaccine.

[53] In October 2019, the European Medicines Agency (EMA) recommended granting conditional marketing authorization for the rVSV-ZEBOV-GP vaccine.

[13] The approval of Ervebo was supported by a study conducted in Guinea during the 2014-2016 outbreak in individuals 18 years of age and older.

[13] The most commonly reported side effects were pain, swelling and redness at the injection site, as well as headache, fever, joint and muscle aches and fatigue.