Xueqing Wu (China)
Zhejiang University
Department of Infectious Disease
I am currently committed to Streptococcus pneumoniae (Spn) related studies, e.g. inter- and intra-species competition within Spn biofilm consortia and pneumococcal epidemiology in China, which will greatly contribute to the reduction of global child mortality from pneumococcal disease. My PhD project focused on investigating the effect of Traditional Chinese Medicine (TCM) and heavy metals on bacterial (Staphylococcus epidermidis) biofilm formation. My postdoc investigation was focused on the mechanisms by which Spn eradicates Staphylococcus aureus (Sau) biofilms and the competition mechanism between different pneumococcal serotypes. I started my assistant researcher position at Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University in 2018 and focus on the Spn epidemiology in China, meanwhile also obtained an NSFC grant supporting my investigation on Spn and Sau competition.

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 Conference Calendar

O077 - EFFECT OF PNEUMOCOCCAL CONJUGATE VACCINE AVAILABILITY ON STREPTOCOCCUS PNEUMONIAE INFECTIONS AND GENETIC RECOMBINATION IN CHINA FROM 2009 TO 2019 (ID 623)

Session Name
0740 - Parallel Session 09: Vaccine Impact (ID 63)
Session Type
Parallel Session
Date
Wed, 22.06.2022
Session Time
15:05 - 16:35
Room
Birchwood Ballroom
Presenter
Lecture Time
16:10 - 16:20

Abstract

Background

How a pause in pneumococcal conjugate vaccine (PCV) vaccination affects pneumococcal disease (PD) or Streptococcus pneumoniae epidemiology is unknown. Based on the unique PCV introduction timeline (PCV gap: April 2015 - April 2017) in China, we aimed to evaluate the effect of the PCV gap on PD and pneumococcal genome variation over the last decade.

Methods

S. pneumoniae isolates (n=386) were collected retrospectively from eight sites in China from 2009 to 2019. Pathogenic pneumococci (n=184) were designated as those collected from blood, cerebrospinal fluid, bronchoalveolar lavage fluid, and infection sites. An interrupted time series analysis was conducted to estimate changes in PD according to PCV availability. The recombination frequency of whole genome-sequenced strains was estimated via SNP calling to reveal pneumococcal genetic variation.

Results

Children were the most infected cohort (n=128), with the major diagnosis being lower respiratory tract infection (LRTI). The ratio of vaccine-type LRTI (VT-LRTI) decreased in the later PCV7 period (2013-March 2015) and increased again in children once PCV7 went off the market in April 2015 (p=0.0007). Increased pneumococcal genetic recombination activity was observed, and the most prevalent clone CC271 strains showed slowed (p=0.0293) recombination activities upon PCV removal.

Conclusions

A PCV gap would restore vaccine-type PD, while bacterial genetic variation also responded accordingly. It is essential to promote a continuous PCV vaccination and strengthen S. pneumoniae molecular epidemiology surveillance for PD prevention. Our findings will benefit PCV vaccination strategies for China and any region that may encounter an unanticipated PCV vaccination pause.

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