Dynamics of Invasive Pneumococcal Disease in Israel in Children and Adults in the 13-Valent Pneumococcal Conjugate Vaccine (PCV13) Era: A Nationwide Prospective Surveillance
Authors: Ben-Shimol Shalom , Regev-Yochay Gili , Givon-Lavi Noga , van der Beek Bart Adriaan , Brosh-Nissimov Tal , Peretz Avi , Megged Orli , Dagan Ron ,   Israeli Pediatric Bacteremia and Meningitis Group (IPBMG), Dagan Ron , Amir Jacob , Barkai Galia , Averbuch Diana , Aviner Shraga , Bachinski Ahuva , Bar-Meir Maskit , Bar-Yochai Avihu , Benedikt Ilana , Bernstein Rita , Brosh-Nissimov Tal , Elias Nael , Engelhard Dan , Ephros Moshe , Glikman Daniel , Gottesman Giora , Grisaru-Soen Galia , Guri Alex , Kasis Imad , Keller Nathan , Korenman Zina , Asher Kuperman Amir , Megged Orli , Miron Dan , Mor Meirav , Ofir-Mintzer Hana , Peretz Avi , Rubinstein Uri , Schlesinger Yechiel , Schwartz David , Shalit Itamar , Somekh Eli , Srugo Isaac , Zbriger Alvira , Zucker Miriam ,   Israeli Adult Invasive Pneumococcal Disease (IAIPD) Group, Regev-Yochay Gili , Assous Marc , Ben-Zvi Haim , Bishara Jihad , Bardenstein Rita , Brik Larissa , Chazan Bibiana , Chowers Michal , Cohen-Poradosu Ronit , Finn Talia , Embon Alicia , Freimann Sarit , Geffen Yuval , Glikman Danny , Hershman Mirit , Istomin Valery , Katzir Michal , Kennes Yoram , Khakshoor Shirley , Khoury-Assi Camellia , Sari Mandelbaum , Maor Yasmin , Miron Danny , Oren Ilana , Paitan Yosi , Paran Yael , Peretz Avi , Potasman Israel , Rahav Galia , Rechnitzer Hagai , Reisenberg Klaris , Sela Shifra , Schwartz David , Schwartz Orna , Shaked-Mishan Pninit , Sheindler Yehudit , Smollan Gill , Srugo Itzhak , Stein Michal , Strahilevitz Jacob , Sverdlob Olga , Temper Violetta , Viener-Well Yonit , Weber Gabriel , Weinberger Miriam , Zimchony Oren , Ztibba Yevgenia 
Published: July 2021

Abstract

Background
Following 13-valent pneumococcal conjugate vaccine (PCV13) implementation in infants worldwide, overall and vaccine-type invasive pneumococcal disease (IPD) rates declined in children, with variable indirect impact on adults.

Methods
A population-based, prospective, nationwide active surveillance of IPD in Israel, 2004–2019 (for adults ≥18 years, 2009–2019). The 7-valent PCV (PCV7)/PCV13 were implemented in Israel in July 2009/November 2010, respectively, with &gt;90% uptake in children &lt;2 years. The 23-valent pneumococcal polysaccharide vaccine (PPV-23) uptake among those &gt;65 years was ~75%. For pre-PCV episodes with missing serotype, extrapolations were applied. Overall, PCV13 serotypes (VT13) and non-VT13 (NVT) incidence rate ratios (IRRs) comparing pre-PCV (2004–2008), early-PCV (2009–2011), and late-PCV13 (2016–2019) periods were calculated for different age groups.

Results
Overall, 8614 IPD cases were recorded. IPD rates declined by 67% in children &lt;5 and 5–17 years, comparing late-PCV13 versus pre-PCV periods (IRR [95% CI]: .33 [.27–.40] and .33 [.21–.50], respectively). For adults, comparing late-PCV13 with early-PCV periods, rates significantly declined by 53% in those aged 18–44, while rates did not decline significantly in other age groups. VT13 rates significantly declined in all ages, with decline rates ranging between 94% in children &lt;5 years and 60% in adults ≥85 years. NVT rates significantly increased in &lt;5-, 50–64-, and ≥65-year age groups. In the late-PCV13 period, serotypes 3, 14, and 19A remained the predominant VT13, while serotypes 8 and 12F emerged as predominant NVTs.

Conclusions
Continuous monitoring of circulating serotypes in all ages demonstrated direct and indirect PCV effects, which are essential for the development of new vaccination strategies.