RSV shapes serotype-specific invasive pneumococcal disease dynamics in children: an observational study.

BACKGROUND

Pneumococcal nasopharyngeal colonization is the first step toward invasive pneumococcal disease (IPD). Respiratory syncytial virus (RSV) may trigger IPD, particularly for serotypes with low disease potential.We aimed to analyse the distribution of pneumococcal serotypes among paediatric IPD according to RSV circulation level.

METHODS

We used data from three continuous French surveillance systems on IPD, pneumococcal carriage and RSV infections from 2008 to 2023. Based on the RSV epidemics threshold, we assessed the proportion of each serotype among IPD, depending on "RSV season" and "non-RSV season". We assessed the correlation between the likelihood of serotype-specific involvement in IPD according to non-RSV season vs RSV season and the estimated disease potential of each serotype.

RESULTS

Among 4,574 IPD cases, the serotype distribution strongly varied during non-RSV season vs RSV season. The lower the disease potential of serotypes, the more RSV circulation enhanced their involvement in IPD (Rho=0.60, CI95% 0.28 to 0.80, p-value = 0.0012).

CONCLUSIONS

The role of RSV in triggering IPD strongly varies across pneumococcal serotypes. The impact of RSV-targeted interventions should be evaluated in light of these data.