How nasopharyngeal pneumococcal carriage evolved during and after a PCV13-to-PCV10 vaccination programme switch in Belgium, 2016 to 2018

Background: The current carriage study was set up to reinforce surveillance during/after the PCV13-to-PCVC10 switch in Belgium. Aim: This observational study monitored carriage of Streptococcus pneumoniae (Sp) serotypes, particularly those no longer covered (3, 6A, 19A), as well as Haemophilus influenzae (Hi), because PCV10 contains the non-typeable Hi protein D. Methods: A total of 2,615 nasopharyngeal swabs from children (6-30 months old) attending day care were collected in three periods over 2016-2018. Children's demographic and clinical characteristics and vaccination status were obtained through a questionnaire. Sp and Hi were identified by culture and PCR. Pneumococcal strains were tested for antimicrobial (non-)susceptibility by disc diffusion and serotyped by Quellung-reaction (Quellung-reaction and PCR for serotypes 3, 6A, 19A). Results: The carriage prevalence of Sp (> 75%) remained stable over the successive periods but that of Hi increased (87.4%, 664 Hi-carriers/760 in 2016 vs 93.9%, 895/953 in 2017-2018). The proportion of non-PCV13 vaccine serotypes decreased (94.6%, 438 isolates/463 in 2016 vs 89.7%, 599/668 in 2017-2018) while that of PCV13-non-PCV10 vaccine serotypes (3 + 6A + 19A) increased (0.9%, 4 isolates/463 in 2016 vs 7.8%, 52/668 in 2017-2018), with serotype 19A most frequently identified (87.9%, 58/66 isolates). Non-susceptibility of pneumococci against any of the tested antibiotics was stable over the study period (> 44%). Conclusions: During and after the PCV13-to-PCV10 vaccine switch, the proportion of non-PCV13 serotypes decreased, mainly due to a serotype 19A carriage prevalence increase. These results complement invasive pneumococcal disease surveillance data, providing further basis for pneumococcal vaccination programme policy making

Synthesis of novel mono- and bisaminophosphoryl compounds and their membrane transport properties for acidic substrates

Some novel aminophosphoryl compounds were synthesized by the Kabachnik-Fields reaction. Their membrane transport properties for mono-and polyfunctional carboxylic acids with different number of functional groups were studied to establish that the transport rate of acidic substrates through liquid impregnated membranes increases in going from mono-to diphosphoryl carriers. Additional hydrophilic groups in the substrate molecule, too, affect transport efficiency. © 2008 MAIK Nauka