Modelling direct and herd protection effects of vaccination against the SARS‐CoV‐2 Delta variant in Australia

Abstract Background Bacterial conjunctivitis is most commonly caused by nontypeable Haemophilus influenzae (NTHi), followed by Streptococcus pneumoniae. No population-based data on the impact of pneumococcal conjugate vaccines (PCVs) on the incidence of bacterial conjunctivitis have been published. We assessed rate dynamics of overall, pneumococcal, and NTHi conjunctivitis in children aged 2–23 months in southern Israel before and after PCV implementation. Methods This is a 12-year prospective, population-based surveillance, from July 2004 through June 2017. Our medical center serves a captive population of approximately 30 000 children < 2 years of age, and its clinical microbiology laboratory processes > 80% of all community-derived cultures, enabling incidence calculation. The 7-valent and 13-valent PCVs (PCV7 and PCV13, respectively) were implemented in the national immunization program in July 2009 and November 2010, respectively. Pneumococci, NTHi, Moraxella catarrhalis, and Streptococcus pyogenes were considered pathogens. Continuous annual incidences and incidence rate ratios comparing the PCV13 period (2015–2017) to the pre-PCV period (2004–2008) were calculated. Results Disease caused by PCV13 serotypes declined by 93%, without significant replacement with non-PCV13 serotypes. Rates of pneumococcal, NTHi, and overall culture-positive episodes declined by 59%, 41%, and 42%, respectively, while rates of culture-negative and other pathogens episodes did not change significantly. An overall reduction in all submitted culture rates of 35% was observed. This pattern was seen across all ages, including infants aged 2–5 months. Conclusions PCV7/PCV13 implementation resulted in a marked and significant decline in pneumococcal, NTHi, and overall conjunctivitis rates in children < 2 years of age. The impact on NTHi episodes alludes to the role of pneumococcus–NTHi interaction in conjunctivitis. The impact in infants aged < 6 months suggests herd protection.

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Herd protection or herding cats?

Thorax ◽

10.1136/thoraxjnl-2018-212585 ◽

2019 ◽

Vol 74 (5) ◽

pp. 425-426 ◽

Cited By ~ 1

Author(s):

Mark van der Linden ◽

Cynthia G Whitney

Keyword(s):

Herd Protection

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Integrating immunizations into the programme

10.1093/med/9780198788850.003.0016 ◽

2019 ◽

Author(s):

Helen Bedford ◽

David Elliman

Keyword(s):

Health Professionals ◽

Social Inequalities ◽

Public Health Intervention ◽

Vaccine Uptake ◽

Health Visitors ◽

Herd Protection ◽

Uptake Rates ◽

Timely Fashion ◽

Child Health Programme ◽

Health Programme

Immunization is a highly successful public health intervention providing protection against serious infectious diseases. UK vaccine uptake rates are generally high, although pockets of lower uptake and social inequalities remain which compromise herd protection. The child health programme provides health professionals opportunities to introduce immunization to parents, offer ongoing information and advice, and remind them when vaccines are due. Improving and maintaining high vaccine rates depends on multicomponent strategies. In view of their relationship with families, health visitors are the key professionals to work with them to ensure that children are immunized fully and in a timely fashion, although in practice they now do not usually deliver vaccines.

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Nationwide Trends of Invasive Pneumococcal Disease in Spain From 2009 Through 2019 in Children and Adults During the Pneumococcal Conjugate Vaccine Era

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1483 ◽

2020 ◽

Cited By ~ 1

Author(s):

Sara de Miguel ◽

Mirian Domenech ◽

Fernando González-Camacho ◽

Julio Sempere ◽

Dolores Vicioso ◽

...

Keyword(s):

Invasive Pneumococcal Disease ◽

Pneumococcal Disease ◽

National Laboratory ◽

Laboratory Data ◽

Pneumococcal Polysaccharide Vaccine ◽

Conjugate Vaccines ◽

Spanish Regions ◽

Herd Protection ◽

Immunocompetent Adults ◽

The Impact

Abstract Background Introduction of pneumococcal conjugate vaccines (PCVs) has reduced the disease caused by vaccine serotypes in children, providing herd protection to adults. However, the emergence of nonvaccine serotypes is of great concern worldwide. Methods This study includes national laboratory data from invasive pneumococcal disease (IPD) cases that affected pediatric and adult populations during 2009–2019. The impact of implementing different vaccine strategies for immunocompetent adults by comparing Spanish regions that used the 13-valent PCV (PCV13) vs regions that used the 23-valent pneumococcal polysaccharide vaccine (PPV23) was also analyzed for 2017−2019. Results The overall reductions in IPD cases by PCV13 serotypes in children and adults were 88% and 59%, respectively, during 2009–2019, with a constant increase in serotype 8 in adults since 2015. IPD cases by additional serotypes covered by PPV23 increased from 20% in 2009 to 52% in 2019. In children, serotype 24F was the most frequent in 2019, whereas serotypes 3 and 8 accounted for 36% of IPD cases in adults. Introduction of PCV13 or PPV23 in the adult calendar of certain Spanish regions reduced the IPD cases by PCV13 serotypes by up to 25% and 11%, respectively, showing a decrease of serotype 3 when PCV13 was used. Conclusions Use of PCV13 in children has affected the epidemiology, reducing the burden of IPD in children but also in adults by herd protection; however, the increase in serotype 8 in adults is worrisome. Vaccination with PCV13 in adults seems to control IPD cases by PCV13 serotypes including serotype 3.

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Estimates of Inactivated Influenza Vaccine Effectiveness Among Children in Senegal: Results From 2 Consecutive Cluster-Randomized Controlled Trials in 2010 and 2011

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1689 ◽

2020 ◽

Author(s):

Mbayame Nd Niang ◽

Jonathan D Sugimoto ◽

Aldiouma Diallo ◽

Bou Diarra ◽

Justin R Ortiz ◽

...

Keyword(s):

Influenza Vaccine ◽

Randomized Controlled Trials ◽

Vaccine Effectiveness ◽

Controlled Trials ◽

Intention To Treat ◽

Randomized Controlled ◽

Herd Protection ◽

Cluster Randomized Controlled Trials ◽

Influenza Illness ◽

Cluster Randomized

Abstract Background We report results of years 2 and 3 of consecutive cluster-randomized controlled trials of trivalent inactivated influenza vaccine (IIV3) in Senegal. Methods We cluster-randomized (1:1) 20 villages to annual vaccination with IIV3 or inactivated poliovirus vaccine (IPV) of age-eligible residents (6 months–10 years). The primary outcome was total vaccine effectiveness against laboratory-confirmed influenza illness (LCI) among age-eligible children (modified intention-to-treat population [mITT]). Secondary outcomes were indirect (herd protection) and population (overall community) vaccine effectiveness. Results We vaccinated 74% of 12 408 age-eligible children in year 2 (June 2010–April 11) and 74% of 11 988 age-eligible children in year 3 (April 2011–December 2011) with study vaccines. Annual cumulative incidence of LCI was 4.7 (year 2) and 4.2 (year 3) per 100 mITT child vaccinees of IPV villages. In year 2, IIV3 matched circulating influenza strains. The total effectiveness was 52.8% (95% confidence interval [CI], 32.3–67.0), and the population effectiveness was 36.0% (95% CI, 10.2–54.4) against LCI caused by any influenza strain. The indirect effectiveness against LCI by A/H3N2 was 56.4% (95% CI, 39.0–68.9). In year 3, 74% of influenza detections were vaccine-mismatched to circulating B/Yamagata and 24% were vaccine-matched to circulating A/H3N2. The year 3 total effectiveness against LCI was −14.5% (95% CI, −81.2–27.6). Vaccine effectiveness varied by type/subtype of influenza in both years. Conclusions IIV3 was variably effective against influenza illness in Senegalese children, with total and indirect vaccine effectiveness present during the year when all circulating strains matched the IIV3 formulation. Clinical Trials Registration ClinicalTrials.gov; NCT00893906.

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Prevalence of cervical disease at age 20 after immunisation with bivalent HPV vaccine at age 12-13 in Scotland: retrospective population study

BMJ ◽

10.1136/bmj.l1161 ◽

2019 ◽

pp. l1161 ◽

Cited By ~ 44

Author(s):

Tim Palmer ◽

Lynn Wallace ◽

Kevin G Pollock ◽

Kate Cuschieri ◽

Chris Robertson ◽

...

Keyword(s):

Cervical Cancer ◽

Population Study ◽

Hpv Vaccine ◽

Cervical Screening ◽

Intraepithelial Neoplasia ◽

Cervical Cancer Prevention ◽

Effective Vaccine ◽

Herd Protection ◽

Cervical Disease ◽

Grade 3

Abstract Objective To quantify the effect on cervical disease at age 20 years of immunisation with bivalent human papillomavirus (HPV) vaccine at age 12-13 years. Design Retrospective population study, 1988-96. Setting National vaccination and cervical screening programmes in Scotland. Participants 138 692 women born between 1 January 1988 and 5 June 1996 and who had a smear test result recorded at age 20. Main outcome measures Effect of vaccination on cytology results and associated histological diagnoses from first year of screening (while aged 20), calculated using logistic regression. Results 138 692 records were retrieved. Compared with unvaccinated women born in 1988, vaccinated women born in 1995 and 1996 showed an 89% reduction (95% confidence interval 81% to 94%) in prevalent cervical intraepithelial neoplasia (CIN) grade 3 or worse (from 0.59% (0.48% to 0.71%) to 0.06% (0.04% to 0.11%)), an 88% reduction (83% to 92%) in CIN grade 2 or worse (from 1.44% (1.28% to 1.63%) to 0.17% (0.12% to 0.24%)), and a 79% reduction (69% to 86%) in CIN grade 1 (from 0.69% (0.58% to 0.63%) to 0.15% (0.10% to 0.21%)). Younger age at immunisation was associated with increasing vaccine effectiveness: 86% (75% to 92%) for CIN grade 3 or worse for women vaccinated at age 12-13 compared with 51% (28% to 66%) for women vaccinated at age 17. Evidence of herd protection against high grade cervical disease was found in unvaccinated girls in the 1995 and 1996 cohorts. Conclusions Routine vaccination of girls aged 12-13 years with the bivalent HPV vaccine in Scotland has led to a dramatic reduction in preinvasive cervical disease. Evidence of clinically relevant herd protection is apparent in unvaccinated women. These data are consistent with the reduced prevalence of high risk HPV in Scotland. The bivalent vaccine is confirmed as being highly effective vaccine and should greatly reduce the incidence of cervical cancer. The findings will need to be considered by cervical cancer prevention programmes worldwide.

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Epidemiology of Respiratory Syncytial Virus-Related Hospitalization Over a 5-Year Period in Italy: Evaluation of Seasonality and Age Distribution Before Vaccine Introduction

Vaccines ◽

10.3390/vaccines8010015 ◽

2020 ◽

Vol 8 (1) ◽

pp. 15

Author(s):

Federica Barbati ◽

Maria Moriondo ◽

Laura Pisano ◽

Elisa Calistri ◽

Lorenzo Lodi ◽

...

Keyword(s):

Intensive Care ◽

Respiratory Syncytial Virus ◽

Age Distribution ◽

Vaccine Introduction ◽

Herd Protection ◽

Infection Risk Factors ◽

Rsv Infection ◽

Syncytial Virus ◽

Italian Children ◽

Tract Infections

Respiratory Syncytial Virus (RSV) is associated with most of the acute viral respiratory tract infections causing hospitalization with a peak during the first months of life. Many clinical trials of RSV vaccine candidates are being carried out. The aim of this study was to obtain epidemiologic information to give suggestions on target populations and prevention strategies before the introduction of new vaccines or monoclonal antibodies. We retrospectively evaluated, over a 5-year period (September 2014–August 2019), a population of hospitalized Italian children aged 0–6 years with a laboratory confirmed diagnosis of RSV infection. Risk factors, seasonality of RSV infection, distribution according to age, cases of coinfections and reinfections and cases needing Intensive Care Unit were evaluated. Hospitalizations due to RSV were 624 in the period under study. The peak was found between November and April, with 80.4% of cases recorded between December and February. 62.5% of cases were found in children under three months of age and 41% in children under 30 days old. The need for intensive care was associated with younger ages, with 70.9% of cases in children below three months of age. Unless the incoming vaccines demonstrate a strong herd protection effect, preventive strategies should be aimed at newborns or at maternal immunization.

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