Respiratory syncytial virus (RSV) vaccine candidate


MVA-BN RSV is our product candidate for the prevention of respiratory syncytial virus (RSV). The vaccine has been designed to target five different RSV proteins to ensure a broad immune response against both RSV subtypes (A & B). The vaccine candidate has been designed to mimic the immune response observed following a natural response to an RSV infection that is believed to induce protection for at least a year.

In 2017, the Company reported data from a Phase 2 study that investigated various schedules and doses of the MVA-BN RSV vaccine in 421 subjects aged 55 and older. This study demonstrated that the vaccine induced robust antibody and T cell responses against RSV with only a single booster vaccination and these responses remained elevated for an entire RSV season (6 months post vaccination). 

As per the original design, the study was extended with 88 subjects being re-enrolled one year later, after having received a single vaccination with either a low or high dose of the vaccine in the Phase 2 study. These subjects were further boosted with the same vaccine dose; mimicking an annual booster regime. The study revealed durable antibody and T cell responses against RSV one year post the original booster vaccination with MVA-BN RSV. These immune responses were significantly boosted following a further annual booster, particularly in the subjects with the weakest immunity at the baseline prior to the second vaccination. Results support an annual booster vaccination with MVA-BN RSV and will be important in discussions with the FDA concerning Phase 3 design later in 2018.

RSV (respiratory syncytial virus) has been recognized as a significant cause of respiratory illness in all age groups. It is highly infectious and the most common cause of lower respiratory tract infection in infants and children worldwide, resulting in a high number of hospitalizations. RSV infections are also a serious health concern in the elderly and in adults with cardiopulmonary disease.

According to estimates from WHO, RSV infects more than 64 million people globally each year and causes a similar number of deaths as influenza, yet unlike influenza, there is no vaccine to prevent RSV.

There are only two subtypes of RSV, A and B, which are typically present either simultaneously or alternately during yearly epidemics.