In May 2023 the US FDA announced approval of Arexvy, the first respiratory syncytial virus (RSV) vaccine to be approved for use in the US and the rest of the world. It has been approved for the prevention of lower respiratory tract disease caused by RSV in patients aged 60 and above. This is a momentous moment, not only for GSK, but for global efforts against RSV, which can be deadly in older people.  

Why RSV? 

As we have previously explored in older posts, the burden of RSV is largely shouldered by older people. Although it usually causes milder symptoms for young people, the CDC suggests that it kills between 6,000 and 10,000 adults over the age of 65 in the US. Apart from this, it results in between 60,000 and 160,000 hospitalisations.  

Dr Barney Graham, senior advisor for global-health-equity trials at Morehouse School of Medicine in Georgia, told Nature that the possibility of having “options available to prevent RSV disease” as a “very big deal”.  

Dr Peter Marks, director of the FDA’s Centre for Biologics Evaluation and Research recognised the approval as an “important public health achievement”. Dr Marks suggests that it reflects the organisation’s “continued commitment to facilitating the development of safe and effective vaccines for use in the United States”.  

Sprint finish to the marathon 

Nature states that “the technology underlying the RSV vaccine” has been “almost 60 years in the making”. From a critical trial in the 1960s, which killed two participating children and hospitalised 80%, to this day, it’s been a long journey. Dr Graham notes that “the first 20 years were spent primarily working out how to make a vaccine that could be safe”.  

In 2008, Dr Graham began a collaboration to better understand the structural biology of the virus, learning that it used protein F to infect a host’s cells. Thus, protein-based vaccines could be developed to elicit a response. However, the team found that early protein-based vaccines were designed around the “wrong form of protein F”, which forms after the virus and cell have already joined. Therefore, the target became the correct form, which hadn’t fully fused with any cell.  

Research published in 2013 allowed companies like GSK to pursue their vaccine candidates. Dr Graham is delighted that his “lifetime’s work” is coming to fruition.  

“It’s very gratifying to see this finally happening.” 

Although the vaccine has been a long time coming, experts are hoping that others will quickly follow suit. For example, Pfizer’s candidate, a protein-based RSV vaccine for older patients awaits approval, and Moderna has an mRNA candidate under expedited review.