‘Comparing serotype coverage of pneumococcal vaccines with PCV21 (V116), a new 21-valent conjugate pneumococcal vaccine, and the epidemiology of its eight unique <i>Streptococcus pneumoniae</i> serotypes (15A, 15C, 16F, 23A, 23B, 24F, 31 and 35B) causing invasive pneumococcal disease in adult patients in Canada: SAVE study, 2018–2021-right-to-reply’

It is our pleasure to reply to the letter of Gokul et al. that discusses data analysis of serotypes 15B and 15C, and 6A and 6C, and the vaccine coverage of these serotypes in our recent publication in JAC.1 We stated in the methods of our manuscript that ‘Serotypes 15B and 15C were grouped together due to the reported reversible switching between these serotypes and documented cross-reactive functional antibodies’. As identified by Gokul et al., there are instances in our manuscript where we inadvertently identified serotypes 15B and 15C separately instead of as serotype 15B/C. Upon review of our data presentation, we have identified 100 isolates that were inadvertently labelled as 15C, instead of 15B/C, and not correctly included in the proportion of isolates covered by PCV20. Similarly, 98 isolates were inadvertently labelled as 15B, instead of 15B/C, and were not correctly included in the proportion of isolates covered by V116. Overall, the proportion of isolates with vaccine serotypes in PCV20 and V116 should have been presented as 3543/5854 (60.5%) and 4540/5854 (77.6%) instead of 3443/5854 (58.8%) and 4442/5854 (75.9%), respectively. While the coverage afforded by each vaccine was underrepresented, the significant difference reported between the serotype inclusion rates of V116 and PCV20 remains unchanged. In each of the demographic and antimicrobial resistance phenotype categories that were detailed in our manuscript, the number of isolates covered by PCV20 and V116 was equally underrepresented by an average of 20 isolates. We regret that individual tables and figures may list 15B or 15C or 15B/15C; however, all notations of 15B or 15C in our manuscript should be taken as referring to 15B/C. This is important as all three vaccines in question (V116, PCV20 and PPSV23) should be regarded as covering serotypes 15B/C. We thank Gokul et al. for their observation and encourage all researchers to be clear and consistent when describing coverage of serotypes 15B/C by each of V116, PCV20 and PPSV23.