Dynamics of Invasive Pneumococcal Disease in Israel in Children and Adults in the 13-Valent Pneumococcal Conjugate Vaccine (PCV13) Era: A Nationwide Prospective Surveillance. (22nd July 2021) - Ben-Shimol, Shalom
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 >90% uptake in children <2 years. The 23-valent pneumococcal polysaccharide vaccine (PPV-23) uptake among those >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 <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 <5 years and 60% in adults ≥85 years. NVT rates significantly increased in <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. Abstract : Ten-year surveillance post–PCV7/PCV13 implementation showed a steep reduction in invasive pneumococcal disease in children and adults, stabilizing after 4 years. The main PCV13 pneumococcal serotypes were 3, 19A, and 14; serotypes 8 and 12F were the leading nonvaccine serotypes.