- Currently no vaccine is available for respiratory syncytial virus (RSV)
- RSV-associated lower respiratory tract illnesses (LRTIs) cause significant global morbidity and mortality in infants under 6 months, including more than 1.4 million hospitalisations every year
- The GRACE study evaluates the safety of the candidate vaccine for pregnant mothers and infants, and its efficacy in infants born to vaccinated mothers
- Phase 1/2 trial demonstrated strong immunogenicity of vaccine candidate
It is estimated that every year, 33 million cases of RSV occur in children less than 5 years of age globally, with more than 1.4 million hospitalisations of infants under 6 months of age[1]. RSV is a leading cause of respiratory infections such as bronchiolitis (inflammation and congestion of the small airways or bronchioles of the lung) and viral pneumonia (an inflammatory condition of the lung small air sacs or alveoli) in infants.
The candidate vaccine contains a recombinant subunit pre-fusion RSV antigen (RSVPreF3) which has shown promising safety and immunogenicity in a phase 1/2 study in non-pregnant women, as presented at the
This candidate vaccine is part of a portfolio of RSV vaccine candidates that GSK is developing, which also includes candidates for children (6-24 months) and older adults. The candidate vaccines are based on different novel technologies, tailored to the needs of the populations most impacted. All three candidate vaccines have received FDA fast-track designation. The phase 3 programme for the older adult's RSV candidate vaccine is on-track to start in the coming months, while the phase 1/2 (in RSV sero-naive infants) study with the paediatric RSV candidate vaccine is ongoing.
About the GRACE Study
The investiGational RSV mAternal vacCinE study (GRACE) is a double-blind phase 3 study (NCT04605159) to be conducted in up to 10,000 pregnant women aged 18-49 years[2]. The trial evaluates the efficacy of a single dose of the RSV Maternal unadjuvanted candidate vaccine administered intramuscularly to pregnant women in good general maternal health aged 18-49 years for the prevention of medically assessed RSV-associated LRTIs in their new-born infants. The study also evaluates the safety of the candidate vaccine both in vaccinated mothers and in their infants.
The study is estimated to end in early 2024, with interim results expected by the second half of 2022.
About GSK's maternal RSV candidate vaccine (GSK3888550A)
The goal of this candidate vaccine is to prevent medically assessed RSV-associated LRTIs in infants during the first 6 months of life by transfer of maternal antibodies - an approach based on GSK's strong expertise in maternal immunisation. The polyclonal nature of the humoral response boosted by this vaccine may offer broad protection and address the potential issue of development of virus escape mutants. If successful, infants would be born with protection due to the passive transfer of neutralising antibodies from the vaccinated mother to the unborn child in the last weeks of pregnancy and therefore no medical intervention in the newborn is required. Maternal immunisation could help to protect infants that are too young to be immunised in their first months of life - when they are most vulnerable to RSV infections.
Data from a phase 1/2 study (NCT03674177) based on 502 healthy non-pregnant women were presented at
Safety and immunogenicity data of the RSV Maternal vaccine candidate from the first clinical study with pregnant women will be presented in the first half of 2021.
About respiratory syncytial virus
Globally, there are an estimated 33 million cases of RSV annually in children less than 5 years of age, with about 3 million hospitalised and approximately 120,000 dying each year from complications associated with the infection. Nearly half of these paediatric hospitalisations and deaths occur in infants less than 6 months of age[3]. According to the
It also represents a significant health threat for older adults, with an estimated 177,000 hospitalisations and 14,000 deaths associated with RSV infections occurring in the US alone[5]. Without robust surveillance systems in several countries, global data on the burden of RSV in older adults is either lacking or likely to underestimate its significance. As global population ages, morbidity and mortality of respiratory infections including RSV to be steadily increasing.
About GSK
GSK is a science-led global healthcare company with a special purpose: to help people do more, feel better, live longer. For further information please visit www.gsk.com.
[1] Shi T. et al,
[2] Since the analysis will be case-driven, incidence rates and vaccine efficacy estimates will drive the actual sample size.
[3] Shi T. et al,
[4]
[5]
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