1173. Changes in Invasive Pneumococcal Disease Incidence Following Introduction of PCV10 and PCV13 Among Children < 5 Years: The PSERENADE Project

Abstract Background Higher valency pneumococcal conjugate vaccines (PCV10 and PCV13) replaced PCV7, and an updated global analysis of PCV impact on invasive pneumococcal disease (IPD) incidence is needed. We aimed to estimate the change in vaccine-type (VT), non-VT type and all-serotype (ST) IPD incidence following introduction of PCV10/13 among children < 5 years of age. Methods IPD ST-specific incidence or cases and population denominators were obtained directly from surveillance sites. IPD incidence rate ratios (IRRs) for each site were estimated comparing the pre-any PCV incidence to each post-PCV10/13 year using Bayesian multi-level, mixed effects Poisson regressions. All-site weighted average IRRs were estimated using linear mixed-effects regressions. Results were stratified by product (PCV10 vs. PCV13) and years of prior PCV7 use (none, some [1-3 years or 4-5 years if < 70% PCV uptake], or many [≥ 4 years with ≥ 70% uptake]). Results Analyses included 45 surveillance sites from 31 countries, primarily high-income (80%). Thirty surveillance sites had pre- and post-PCV data (PCV10: no prior PCV7=5 sites, some=2, many=2; PCV13: no prior PCV7=3, some=5, many=13). Five years after PCV10/13 introduction, the all-site IRRs in children < 5 years were generally similar across products and prior PCV7 use strata for all-serotype IPD (range 0.23-0.41), PCV7 STs (0.01-0.13), PCV10non7 STs (1, 5, and 7F; 0.05-0.20), and ST6A (0.01-0.18). IRRs for ST19A were lower for PCV13 sites (range by PCV7 use: 0.09-0.31) than for PCV10 sites (1.1-1.4). ST3 IRRs were dynamic, differing by product at year 5 (range for PCV13 sites=0.86-1.02; PCV10 sites=1.55-1.78), but converging by year 7. NonPCV13 STs increased across all strata (range 1.9-2.6), except one strata with a single African site that declined. Figure 1. All-Site Weighted Average Incidence Rate Ratios, Children <5> * Total sites indicates number of sites with incidence rate data included and pre/post sites indicates number of sites with both pre- and post-PCV data to estimate IRRs for each outcome. ** Year 0 indicates the year of PCV10/13 introduction and year -1 indicates the last year of PCV7 use prior to PCV10/13 introduction. Conclusion All-serotype IPD in children < 5 years declined following both PCV10 and PCV13 use, driven by substantial declines in VT serotypes and offset by increases in nonPCV13 STs. ST19A decreased among PCV13-sites, mitigating replacement disease occurring after PCV7 use, but increased, on average, among PCV10-sites. Changes in ST3 were heterogeneous, increasing in some sites and no change from baseline in others. Data from low-income and high-burden settings were limited. Disclosures Julia C. Bennett, MSPH, Pfizer (Research Grant or Support) Maria Deloria Knoll, PhD, Merck (Research Grant or Support)Pfizer (Research Grant or Support)


Figure 1. Measles and Rubella Age-specific Seroprevalence
The lines represent generalized additive model fits for the mean (solid) and 95% confidence intervals (dashed). Data are grouped by age in years and year 0 includes only specimens from children 9-11 months. Rubella-containing vaccine was not available in the public sector prior to the serosurvey.
Conclusion. Measles seroprevalence was lower among HIV-infected than uninfected children and youth. HIV-infected children would likely benefit from revaccination. Many children were susceptible to rubella before the introduction of the combined measles and rubella vaccine in Zambia.
Disclosures. Kyla Hayford, PhD, MA, Pfizer, Inc. (Other Financial or Material Support, KH conducted the study and analyses while working at the Johns Hopkins School of Public Health but is an employee at Pfizer, Inc. as of 26 October 2020.) Background. SARS-CoV-2 vaccine hesitancy (VH) is hindering nationwide vaccination efforts; little is known about caregiver SARS-CoV-2 vaccine acceptance for children. We aimed to identify associations with SARS-CoV-2 VH in caregivers of hospitalized children.

SARS-CoV-2 Vaccine Hesitancy in Caregivers of Hospitalized Children
Methods. We conducted a prospective cross-sectional survey in English and Spanish of caregiver COVID-19 knowledge, attitudes, behaviors, and associated VH among hospitalized children 6 months -18 years at a large pediatric medical institution. Parents were approached daily, averaging 4-5 days/week, from 12/8/2020--4/5/2021. VH was assessed using the Parent Attitudes about Childhood Vaccines (PACV) survey; PACV score ≥50 denoted VH. Descriptive statistics and multivariable logistic regression were used. Responses were categorized.
Results. 295/307 (96%) of approached caregivers enrolled; 79% were ≥ 30 years, 68% were married/ living with a partner, and 57% had at least some college. 36% identified as white, 19% Black, and 46% Hispanic/ Latino. 53% of caregiver children had public insurance. 91% of caregivers self-reported their children were up to date with routine vaccines. 17% of caregivers were vaccine-hesitant overall. 50% of caregivers were willing to receive COVID-19 vaccine themselves. Figure 1 shows intention to vaccinate their child by PACV score.
65% knew someone who was hospitalized for COVID-19. 67% were scared of their child getting COVID-19. However, 49% were scared of their child getting the vaccine, 28% did not want to vaccinate their child and 27% were neutral in the intention to vaccinate their child. Caregivers who did not intend to vaccinate their child were more likely to be Black (27% vs. 16%, p=0.04) and less likely to be Hispanic/ Latino (33% vs. 49%, p=0.02). Table 1 shows attitudes, beliefs, and behaviors surrounding the COVID-19 pandemic and vaccine in caregivers who did or did not intend to vaccinate their child. COVID-19 vaccine uptake by PACV score Table 1 Caregiver attitudes, beliefs, and behaviors surrounding the COVID-19 pandemic and the COVID-19 vaccine Conclusion. The majority of caregivers believe that SARS-CoV-2 vaccine will help control the pandemic, but less than half plan to vaccinate their children. A quarter of caregivers expressed uncertainty regarding the vaccine and therefore may be amenable to education and discussion. COVID-19 VH is different from VH towards routine vaccinations. More research is needed to address COVID-19 specific VH. Background. Higher valency pneumococcal conjugate vaccines (PCV10 and PCV13) replaced PCV7, and an updated global analysis of PCV impact on invasive pneumococcal disease (IPD) incidence is needed. We aimed to estimate the change in vaccine-type (VT), non-VT type and all-serotype (ST) IPD incidence following introduction of PCV10/13 among children < 5 years of age.
Methods. IPD ST-specific incidence or cases and population denominators were obtained directly from surveillance sites. IPD incidence rate ratios (IRRs) for each site were estimated comparing the pre-any PCV incidence to each post-PCV10/13 year using Bayesian multi-level, mixed effects Poisson regressions. All-site weighted average IRRs were estimated using linear mixed-effects regressions. Results were stratified by product (PCV10 vs. PCV13) and years of prior PCV7 use (none, some [1-3 years or 4-5 years if < 70% PCV uptake], or many [≥ 4 years with ≥ 70% uptake]).