Summary of the main points of the study (IMAGE) Institut Pasteur Caption Development of two poxvirus seroneutralization assays using MVA or MPXV. Complement enhances neutralizing activity of antibodies (NAbs). Historic smallpox vaccination increases the level of antibodies induced by infection or MVA vaccination. Credit (c) Institut Pasteur Usage Restrictions (c) Institut Pasteur License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.