Respiratory syncytial virus (RSV)-associated infections in older adults impose a substantial economic burden on Hong Kong’s public health system, but the good news is that this burden may be mitigated by vaccination.

In research conducted by GlaxoSmithKline’s Medical Evidence Generation, roughly 65,159 cases of symptomatic RSV-associated acute respiratory infection?including 34,141 upper (URTD) and 31,018 lower respiratory tract disease (LRTD)?were estimated to occur annually among 2,236,600 older adults at least 60 years of age in Hong Kong. [APSR 2024, abstract AO10-005]

The annual economic burden of RSV-associated acute respiratory infections in the older adult population was projected at HKD 569 million, with LRTD accounting for HKD 554 million and URTD for HKD 15 million.

“RSV-associated infection commonly causes acute respiratory illness in older adults and adults who are at increased risk due to comorbidities,” said first author Willy Ho, director of Medical Evidence Generation at GSK, Singapore.

Ho noted that while such infections often present as mild cold-like symptoms, it can progress to severe complications that result in hospitalizations or deaths.

The findings indicate that RSV-associated infection among older adults represents a substantial clinical and economic burden on the public health system in Hong Kong, he added.

The analysis was conducted using a multi-cohort Markov design with a 1-month cycle length, with a cost-of-illness model estimating the annual economic burden of symptomatic RSV-associated infections among older adults from a healthcare payer perspective. Model inputs were obtained from relevant literature specific to Hong Kong, including data from government sources and insurance entities.

RSV vaccination

In a separate analysis, the AS01_E-adjuvanted RSV prefusion F protein-based vaccine (adjuvanted RSVPreF3) was shown to substantially reduce RSV burden among older adults in Hong Kong.

In the absence of vaccination, around 192,109 cases of symptomatic RSV-associated infection were estimated to occur among 2,236,600 older adults at least 60 years of age. This was projected to result in 164,528 outpatient visits, 24,676 hospitalizations, and 1,038 deaths. [APSR 2024, abstract AO10-005]

However, by administering a single dose of the adjuvanted RSVPreF3 to 1,080,278 older adults, approximately 31,717 cases of symptomatic RSV-associated infection, 29,100 outpatient visits, 5,985 hospitalizations, and 253 deaths over 3 years could be prevented.

“The adjuvanted RSVPreF3 is a preventive intervention against RSV-associated LRTD approved for older adults in Hong Kong,” Ho said.

He pointed out that the present data demonstrate the potential public health benefits of RSV vaccination programs in the older adult population.

For the analysis, a multi-cohort Markov model with a 3-year time horizon and each simulation cycle lasting 1 month was designed to compare health outcomes in scenarios wherein a single dose of the adjuvanted RSVPreF3 was administered vs not administered to older adults in Hong Kong. Vaccine efficacy (VE) data from phase III clinical trials (peak VE against RSV-associated acute respiratory infection 74.17 percent, linear monthly waning 2.26 percent; peak VE against RSV LRTD 88.02 percent, linear monthly waning 2.10 percent) spanning two complete RSV seasons (median follow-up of 17.8 months) were incorporated into the model.