Why are 75 year olds in the UK being offered a vaccine against RSV?

Professor Roy L Soiza is a Consultant Geriatrician and Honorary Chair in Old Age Medicine at the University of Aberdeen, as well as Editor-in-Chief of Age & Ageing. He has a special interest in vaccine trials as well as the safety and effectiveness of medications in older people. 

Vaccination against Respiratory Syncytial Virus (RSV) has been added to the UK’s immunisation programme this Summer. From 1^st August 2024, all those turning 75 years in Scotland are being invited to receive the vaccine, with the rest of the UK following suit from September 2024. Additionally, a ‘catch-up’ programme for those aged 75-79 will be running concurrently. Geriatricians are notoriously sceptical about new drugs and many will wonder whether they should really be recommending a vaccine against a virus that, by reputation, is dangerous only to infants and very young children, and only causes a common cold-like illness in others. However, evidence of a substantial burden of illness and mortality of RSV in older adults has grown in recent years. Moreover, two vaccines against RSV have been licensed in the last year. A Commentary in Age & Ageing published this week examines the evidence of safety and efficacy of the new RSV vaccines, with a special focus on older, frail individuals.

Although it is true that most cases of RSV infection result in only mild respiratory illness, the documented incidence of hospitalisation in those aged 75 of over in the UK is 65 per 100,000 population per year. That is roughly only a quarter of the incidence of hospitalisations from influenza. However, this is likely to be a serious underestimate because of incomplete testing. The best estimates of the true burden place the burden of RSV infection in older people very close to that of influenza. A recent systematic review estimated RSV in older people results in over 175,000 GP episodes and kills almost 8000 older people every year in the UK. Therefore, a vaccine against RSV has potential to significantly reduce morbidity and mortality.

The UK will be using the Abrysov® vaccine developed by Pfizer and licensed largely on the back of interim results from the RENOIR randomised controlled trial. The trial was conducted in multiple centres across Argentina, Canada, Finland, Japan, the Netherlands, South Africa and the United States. They recruited over 34,000 participants aged 60 years or over (over a third were 70 or over but only 5.6% were aged 80 or over). Just over half of all participants had significant co-morbidities defined as more than one of a list of pre-specified conditions such as chronic lung or heart disease. This was a double blinded placebo-controlled trial. In the first year after vaccination, the rate of RSV-confirmed lower respiratory tract infections was 85.7% lower (95% confidence interval 32.0-98.7%) in those that received the RSV vaccine compared to those in the placebo arm. The vaccine was very well tolerated – the incidence of local reactions at the site of injection was 12% (compared to 7% in the placebo arm) with no difference in the incidence of systemic reactions (27% v 26%). Serious adverse events were extremely rare, with no significant differences across intervention and placebo arms. Moreover, results from another rival RSV vaccine by GSK, marketed as Arexy®, were similarly positive, prompting the UK’s Joint Committee on Vaccinations and Immunisations to recommend vaccination in those aged 75 or over. In their cost-effectiveness analysis, they recommended that such a vaccination programme would be more cost-efficient than one aimed at all over 65s. They estimated that, if a 70% vaccine uptake rate could be achieved, then the progamme would prevent 36,000 GP consultations, 4,600 hospitalisations, 1000 intensive care admissions and anything between 300 to 2800 deaths every year. This rate is achievable based on the uptake of COVID and influenza vaccines in the UK.

One lamentable factor is that recruitment of frailer older individuals in trials of these vaccines was limited. This is a pity as they usually have the most to gain from vaccination. During the COVID pandemic, there was a similar issue when the COVID vaccination programme was rolled out in care home residents and the frailest individuals first in recognition they were most in danger and would probably have most to gain from vaccination despite their systematic (and arguably unnecessary and unjustifiable) exclusion from trials. Luckily, COVID vaccine effectiveness in this group closely matched that seen in trials. Hopefully the same will be true for RSV vaccines. Overall, we think the adoption of the RSV vaccine into the national immunisation programme for older people is excellent news. We strongly recommend colleagues encourage patients, carers and relatives to ensure those invited for vaccination take up the offer. Although the mass testing of the new vaccines in older people including those with significant comorbidities is very welcome, we hope vaccine manufacturers redouble their efforts to ensure their trial population matches more closely that of their future clientele. Meanwhile, the RSV vaccination programme promises to positively reduce the impact of this condition on an over-stretched NHS, as well as improving the wellbeing of those turning 75 years old.

Read the Age and Ageing article in full:  Why the UK is vaccinating its older adult population against RSV—what geriatricians should know