Recent advances in the development of subunit-based RSV vaccines

Abstract

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections causing pneumonia and bronchiolitis in infants. RSV also causes serious illness in elderly populations, immunocompromised patients and individuals with pulmonary or cardiac problems. The significant morbidity and mortality associated with RSV infection have prompted interest in RSV vaccine development. In the 1960s, a formalin-inactivated vaccine trial failed to protect children, and indeed enhanced pathology when naturally infected later with RSV. Hence, an alternative approach to traditional killed virus vaccines, which can induce protective immunity without serious adverse events, is desired. Several strategies have been explored in attempts to produce effective vaccine candidates including gene-based and subunit vaccines. Subunit-based vaccine approaches have shown promising efficacy in animal studies and several have reached clinical trials. The current stage of development of subunit-based vaccines against RSV is reviewed in this article.

Respiratory syncytial virus–Host interaction in the pathogenesis of bronchiolitis and its impact on respiratory morbidity in later life

“…The catastrophic failure of the 1960 formalin‐inactivated RSV vaccine (FI‐RSV) has been a barrier, for many years, to the development of new vaccine for many years. Indeed, FI‐RSV vaccine not only failed to protect against wild‐type RSV disease but also induced an exaggerated inflammatory response in infants RSV naive before vaccination . Many children were hospitalized with LTRI, and, tragically, two infants died following naturally occurring RSV infection.…”

Respiratory syncytial virus

“…Due to the labor-intensive nature and technical expertise required for the technique, it is largely restricted to reference laboratories and large teaching hospitals [6,7]. The labile nature of RSV also means it can lose viral infectivity rapidly unless there is proper storage and rapid transport of specimens for laboratory testing.…”

“…Despite these hurdles, a large number of potential vaccines are under development and the likelihood of one or more successful vaccine reaching the market within the next decade is high (6,155). These vaccines fall into four broad categories: live attenuated, subunit, vector-based and particulate.…”

“…Molecular techniques such as real time PCR (qPCR) have now become more affordable and offer rapid and accurate diagnostics, with the ability to identify the disease earlier in at-risk patients, at levels of viral burden too low for conventional detection and affording the potential for community-based epidemiology (4,5). Intensive research in recent decades has accelerated progress on many fronts, with several promising new vaccines in advanced stages of development (6,7). In countries with limited access to healthcare, an effective and affordable vaccine would be transformative.…”

Acute viral bronchiolitis: Dawn of a new era for the prevention of respiratory syncytial virus infection through vaccination

“…[1] These include the next generation of re-engineered live attenuated RSV vaccines, vector-based vaccines, F-protein-based subunit vaccines, including the use of nanoparticle technology or targeting the prefusion epitopes of the F-protein. [2,3] The strategy to optimise the protection of young infants, considering that the mean age for contracting RSV is usually 4 -5 months and that these children might be too young to benefit from active vacci nation, has also recently undergone a paradigm shift. In particular, it has been accepted that pregnant women may potentially be vacci nated to protect their infants against illness during the first 3 -4 months of life by enhancing transplacental acquisition of vaccine-induced maternal antibody.…”