The FDA recently approved Arexvy® in the United States. It’s the world’s first respiratory syncytial virus vaccine. Read more about the risks and benefits.
RSV, a highly contagious, seasonal virus, can cause severe infections of the respiratory system in patients of all ages. A rise in infections can typically be seen during fall and peaking in winter. During and in the aftermath of the COVID-19 pandemic, RSV infections – while still an important cause of hospitalization in infants under 1-year old – became more frequent in older children as well. In older adults, at whom this vaccine recently approved by the FDA is targeted, RSV infections can result in fatal cases of pneumonia and bronchiolitis. According to the CDC, each year in the U. S., RSV leads to approximately 60,000–160,000 hospitalizations and 6,000–10,000 deaths among adults 65 years of age and older.
Now, Arexvy® meets the need for a vaccine, at least for older patients. Based on an analysis of data from a clinical study, the FDA confirmed the vaccine’s safety and effectiveness, administered as a single dose. The study is an ongoing, randomized, placebo-controlled clinical trial, conducted in the U. S. and internationally, including participants aged 60 and older. They will remain in the study group though three RSV seasons in order to “assess the duration of effectiveness and the safety and effectiveness of repeat vaccination”. According to the collected data, participants who have received the vaccine had a significantly reduced risk (82.6 %) of developing lower respiratory tract disease (LRTD), a sickness often associated with RSV. The vaccine also reduced the risk of developing severe RSV-associated LRTD by 94.1 %.
Reported side effects were expectable: injection site pain, fatigue, muscle pain, headache and joint stiffness/pain. However, some individuals also developed atrial fibrillation within 30 days of vaccination (10 participants in Arexvy® group, 4 in placebo group). In two other studies, 2,500 participants 60 years of age and older received Arexvy® – and further side effects were reported. In the first study, two participants who received the RSV jab and an influenza vaccine developed acute disseminated encephalomyelitis (ADEM), a rare type of inflammation affecting the brain and spinal cord; one of them died. In the second, one participant developed Guillain-Barré syndrome – a rare neurological disorder – 9 days after receiving the vaccine.
As stated in a press release, “[t]he FDA is requiring the company to conduct a postmarketing study to assess the signals of serious risks for Guillain-Barré syndrome and ADEM”. According to the FDA, the company is also planning to assess atrial fibrillation observed in one of the trials. Peter Marks, M. D., Ph. D., director of the FDA’s Center for Biologics Evaluation and Research, stressed the importance of the vaccine’s approval: “[It] is an important public health achievement to prevent a disease which can be life-threatening […].”
Image source: Liam McGarry, unsplash
