The results of a US-based analysis examining COVID-19-related changes in paediatric 13-valent pneumococcal conjugate vaccine (PCV 13) use and its subsequent impact on pneumococcal disease rates do not support PCV13 use in non-immunocompromised adults aged ≥65 years.

The cost-effectiveness analysis published in Vaccine used a Markov model to estimate paediatric disease resulting from decreased PCV13 use in children aged <5 years, with absolute decreases ranging from 10%−50% over 1−2 years' duration examined. The model assumed no catch-up vaccination and that decreased vaccination led to proportionate increases in pneumococcal disease in children and older adults. The output of this model was then used to populate a second Markov model that estimated the cost effectiveness of older adult pneumococcal vaccination strategies accommodating potential epidemiologic changes from decreased paediatric PCV 13 vaccination.

One year of 10%−50% absolute decreases in PCV 13 use in the under 5-year-olds increased pneumococcal disease by around 4%−19% in ≥65 year olds; after 2 years of decreased PCV 13 use, disease rates increased in older patients by 8%−38%. However, at a cost-effectiveness threshold of $US200 000 per quality-adjusted life-year (QALY) gained, PCV 13 use in all ≥65 year-olds would only be favoured when there was a >53% increase in pneumococcal disease, this corresponded to absolute decreases in paediatric PCV 13 vaccination of >50% over a 2-year period. An alternative vaccination strategy (PCV 13 of immunocompromised ≥65 year-olds only) was favoured at a the $200 000 per QALY gained threshold when the relative increase in senior pneumococcal disease rates was >10%, corresponding to decreases in paediatric PCV 13 use of >30% over 1 year and >20% over 2 years.

"Decreases in pediatric PCV 13 use, which could increase pneumococcal disease incidence in both children and seniors, would need to be substantial and prolonged to influence the cost-effectiveness of the current pneumococcal vaccination recommendations for adults 65 years old", conclude the authors.