Changes in Invasive Pneumococcal Disease in the Paediatric Population in the Second COVID-19 Pandemic Year.

Incidence of invasive pneumococcal disease (IPD) decreased worldwide in 2020, coinciding with the implementation of measures to reduce COVID-19 transmission. We evaluated the impact of the COVID-19 pandemic on healthcare demand and IPD in children in 2021 compared to the pre-pandemic period (2018–2019) and the early pandemic period (2020) in a study carried out during 2018–2021 in Catalonia. Incidence rates were compared by calculating the incidence rate ratio (IRR), and expressing percentage changes in IRR as (1-IRR)x100. Compared to 2018–2019, emergency room (ER) visits declined by 21% in 2021 (p < 0.001), mainly in the first quarter (−39%), and compared to 2020, ER visits increased by 22% in 2021 (p < 0.001), except in the first quarter. IPD incidence overall was 11.0 in 2018–2019 and 4.6 in 2021 (−58%, p < 0.001); the reduction in incidence was similar in the 0–4 age group and was higher in the first quarters. Compared to 2020, in 2021, IPD incidence decreased during the first quarter (−86%, p < 0.001), but increased from 0.0 to 1.2 in the second quarter (p = 0.02) and from 0.6 to 2.1 (p=0.03) in the fourth quarter. The decreased IPD incidence observed in 2021 compared to 2018–2019 (most especially in the first quarter) was greater than the decrease in healthcare demand and PCR test requests. Compared to 2020, IPD incidence decreased in the first quarter when a second state of alarm was in force. In 2021, compared to 2018–2019, there was a greater reduction in PCV13 serotypes than in non-PCV13 serotypes.