Immune Responses to Novel Adenovirus Type 26 and Modified Vaccinia Virus Ankara–Vectored Ebola Vaccines at 1 Year

Immune Responses to Novel Adenovirus Type 26 and Modified Vaccinia Virus Ankara-Vectored Ebola Vaccines at 1 YearThe Ebola virus vaccine strategies evaluated by the World Health Organization in response to the 2014-2016 outbreak in West Africa included a heterologous primary and booster vaccination schedule of the adenovirus type 26 vector vaccine encoding Ebola virus glycoprotein (Ad26.ZEBOV) and the modified vaccinia virus Ankara vector vaccine, encoding glycoproteins from Ebola, Sudan, Marburg, and Tai Forest viruses nucleoprotein (MVA-BN-Filo).This schedule has been shown to induce immune responses that persist for 8 months after primary immunization, with 100% of vaccine recipients retaining Ebola virus glycoprotein-specific antibodies. 1 A vaccine that provides durable immune responses is important in maintaining sustained protection against disease, both during outbreaks and outside of an outbreak for at-risk populations, such as health care and aid workers in risk areas, individuals in areas experiencing low-grade endemic disease, 2 and contacts of Ebola survivors, given evidence of prolonged shedding of the virus from body fluids with the potential for transmission.3,4 We report the 1-year data for the study of the Ad26.ZEBOV and MVA-BN-Filo vaccines, 1 the longest duration follow-up for any heterologous primary and booster Ebola vaccine schedule to our knowledge.Methods | The single-center, randomized, placebo-controlled, observer-blind, phase 1 trial received approval from the National Research Ethics Service.Participants provided written Responder, No. (%) [95% CI] a 4 (31) [9-61] 1 (8) [0-36] 4 (40) [12-74] 3 (25) [5-57] 1 (10) [0-45] (continued)