Novel vaccine candidate under investigation for the prevention of respiratory syncytial virus (RSV) disease in older adults begins Phase II clinical study


Tonya Villafana

Respiratory Syncytial Virus (RSV) is a common seasonal virus that typically causes illness during the winter respiratory virus season in temperate zones and is clinically indistinguishable from influenza.

It can however cause very serious - even fatal - respiratory illness such as bronchiolitis and pneumonia in infants and in older adults who are otherwise healthy or who have chronic underlying medical conditions. Each year, an estimated 14,000 adults over the age of 65 die in the United States alone from complications related to RSV-related disease. Symptomatic reinfection is common in adults.

There is no approved vaccine or treatment for RSV in older adults. The burden of disease and unmet medical need is being increasingly recognized as the older adult population continues to grow.

The team at AstraZeneca and MedImmune is hopeful that our novel vaccine candidate for RSV, MEDI7510, which has just started Phase II clinical trials, will become the important vaccine needed to address this unmet need and to help prevent older adults from developing RSV disease.

MEDI7510 combines RSV sF antigen and GLA-SE adjuvant. The vaccine is designed to maximize both the humoral and cell-mediated immune (CMI) response to RSV in older adults. Our company and others have previously published that older adults are deficient in their RSV-specific CMI responses and the adjuvant helps to overcome this deficiency.

Data from the Phase I program show MEDI7510 demonstrates safety and immunogenicity profiles that support our hypothesis and the progression into Phase II efficacy studies. Dr. Judy Falloon, clinical development lead for the program, will be presenting key elements of the Phase I data at the RSV Vaccines for the World conference, Nov. 18 – 20, 2015, at The Salk Institute in LaJolla, California.

The Phase II study aims to evaluate the efficacy of MEDI7510 for the prevention of acute RSV-associated respiratory illness and is currently enrolling in the US. More information can be found at