People who received an Ebola virus vaccine maintained immune response one year after vaccination, according to a research letter from Rebecca L.Winslow, MRCGP, of the University of Oxford (UK) and her associates.
The immune response of 64 vaccine recipients of European descent 360 days after receiving either adenovirus type 26 vector vaccine encoding Ebolavirus glycoprotein (Ad26.ZEBOV) followed by modified vaccinia virus Ankara vector vaccine (MVA-BN-Filo), or MVA-BN-Filo followed by Ad26.ZEBOV. The 360 day follow-up occurred 120 days after the previous follow-up, during which time no significant adverse events were reported.
All vaccine recipients maintained Ebola virus-specific immunoglobulin G responses at 360 day follow-up. A majority of all vaccine recipients showed vaccine-induced T-cell responses, however, maintenance was slightly superior in the group that received MVA-BN-Filo first. CD8+ T cell response were maintained well by both groups, however, CD4+ T cells were not reliably maintained after 360 days.
“Immune responses may differ in a sub-Saharan African population; these vaccine candidates are being assessed in this region. Additional research is also warranted to explore the persistence of immunity beyond 1 year following immunization and response to booster doses of vaccine,” the investigators concluded.
Find the full research letter in JAMA (doi: 10.1001/jama.2016.20644 )