Kofo.A Odeyemi, NigeriaCollege of Medicine University of Lagos/Lagos University Teaching Hospital Community Medicine and Primary Care
Poster Author Of 1 e-Poster
EARLY IMPACT OF INTRODUCING A TEN-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV10) ON PNEUMOCOCCAL CARRIAGE IN NIGERIA
Author Of 2 Presentations
ANTIMICROBIAL RESISTANCE PATTERNS IN PNEUMOCOCCAL CARRIAGE PRE AND POST PCV10 INTRODUCTION IN NIGERIA (ID 521)
Pneumococcal conjugate vaccines (PCVs) reduce antimicrobial resistance (AMR). In Africa, where disease surveillance is limited, nasopharyngeal carriage studies may reveal PCV impact on AMR . We investigated AMR in pneumococcal carriage in Nigeria.
Nigeria introduced PCV10 between 2014-2016. Random carriage surveys targeting 1000 participants were conducted pre-(2016) and post-PCV10 (2017-2018) in two locations (rural and urban). PCV10 coverage in 2017 and 2018 was 47% and 55%, respectively. Isolates randomly selected from each survey were tested for antimicrobial resistance using broth micro-dilution.
In 571 pneumococcal isolates, prevalence of resistance was -Tetracycline (69%), Cotrimoxazole (68%), Penicillin (43%) and Chloramphenicol (14%). Serotypes 19F, 6A, 11A, 23F, 3, 16F, 19A, 34 and 6B had a high prevalence of resistance. Prevalence of resistance to any antibiotic differed little by pre- vs post-PCV10 era both overall (86% and 85%) and in rural (73% and 71%) and urban (99% and 98%) samples. No difference was seen in prevalence of resistance among vaccine and non-vaccine serotypes by PCV10 era.
Among healthy Nigerians, prevalence of resistance to commonly used antibiotics is high in carried pneumococci. Although the data do not show any impact of PCV10 on resistance prevalence, the lack of effect may be explained by incomplete coverage levels.
EARLY IMPACT OF INTRODUCING A TEN-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV10) ON PNEUMOCOCCAL CARRIAGE IN NIGERIA (ID 652)
As Nigeria transitions from Gavi-support to self-financing of the pneumococcal conjugate vaccine (PCV), decisions on vaccine cost effectiveness should be based on local vaccine impact data. Herd immunity against carriage is a major contributor to PCV impact. So, carriage surveys are a useful option for impact assessments in the absence of disease surveillance systems.
We conducted nasopharyngeal carriage surveys (2017-2019) according to WHO guidelines among randomly selected residents of two locations (urban and rural) in Nigeria. PCV10 was introduced in 2016 in these locations and reached a modest coverage of 37% and 61% by 2019. Carriage prevalence ratios (PR) before and after PCV10 introduction were estimated using log-binomial regression.
There was a 38% (PR-0.62 [95%CI:0.53-0.72]) and 21% (PR-0.79 [95%CI:0.66-0.94]) reduction in carriage of vaccine serotypes respectively among vaccine-target (<5years) and non-target) (5+ years) groups, mostly due to serotypes 19F, 23F and 6B. Carriage of non-vaccine serotypes increased by 28% (PR-1.28 [95%CI:1.15-1.42]) and 31% (PR-1.31 [95%CI:1.20-1.43]) respectively in these groups; serotypes 6A, 19A, 34, 16F and 11A were prominent.
Within three years of PCV10 introduction, we found early evidence of direct and indirect PCV effects on vaccine serotype carriage as well as serotype replacement in carriage.