Monica L. Nation (Australia)
Murdoch Children’s Research Institute
Infection and Immunity
Monica is an epidemiologist and microbiologist working in pneumococcal vaccine research at Murdoch Children's Research Institute (Australia). She has a particular interest in vaccine impact evaluation, optimizing vaccine schedules, and the impact COVID-19 has had on respiratory infections and disease.

Presenter of 1 Presentation

 Conference Calendar

O016 - IMPACT OF COVID-19 NON-PHARMACEUTICAL INTERVENTIONS ON PNEUMOCOCCAL CARRIAGE AND DENSITY IN VIETNAM (ID 442)

Session Name
0330 - Parallel Session 03: Pneumococcal Disease and Pneumonia in the Time of COVID-19 (ID 25)
Session Type
Parallel Session
Date
Mon, 20.06.2022
Session Time
15:20 - 16:35
Room
Grand Ballroom East
Presenter
Lecture Time
15:45 - 15:55

Abstract

Background

Non-pharmaceutical interventions (NPIs) associated with the COVID-19 pandemic have resulted in decreases in invasive pneumococcal disease. Previous studies propose the decline is due to reduced pneumococcal transmission and/or suppression of respiratory viruses. Nasopharyngeal colonization is required for transmission and disease, yet few studies have evaluated the impact of NPIs on pneumococcal carriage. Here we report pneumococcal carriage and density during the COVID-19 pandemic in Ho Chi Minh City, Vietnam.

Methods

Nasopharyngeal samples from children aged 24 months enrolled in a trial investigating reduced-dose schedules of pneumococcal conjugate vaccines were assessed in three periods: pre-COVID (n=1393), NPI period 1 (school closures and bans on public gatherings, n=307), NPI period 2 (post-national lockdown with mask-wearing mandate, n=262). Pneumococci were quantified by lytA qPCR and serotyped by microarray. Carriage prevalence and density were assessed in each NPI period compared with the pre-COVID period using logistic and linear regression adjusted for age, district, respiratory symptoms, antibiotic use, and season.

Results

No changes in carriage prevalence were observed in either NPI period compared with pre-COVID. Overall density decreased by 0.41log10genome equivalents (GE)/ml (95%CI: 0.09-0.73) and 0.75log10GE/ml (0.40-1.11) in NPI periods 1 and 2 compared with pre-COVID. Greater reductions were found for density of capsular (0.47log10GE/ml decrease (0.09-0.85) and 1.07log10GE/ml decrease (0.66-1.47)) than non-encapsulated pneumococci (0.49log10GE/ml decrease (0.02-0.95) and 0.24log10GE/ml decrease (-0.30-0.77; p>0.05) in periods 1 and 2 compared with pre-COVID.

Conclusions

Pneumococcal carriage did not vary during the COVID-19 pandemic. The observed reduction in pneumococcal density may provide a plausible mechanism for the decline in invasive pneumococcal disease.

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