Pneumococcal conjugate vaccine failure in children: A systematic review of the literature.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) are highly effective in preventing pneumococcal invasive disease (IPD) due to serotypes included in the vaccines. The risk of vaccine-type IPD in immunised children (i.e. vaccine failure) has not been systematically assessed in countries with established PCV programmes. METHODS: We undertook a systematic review of the English literature published from January 2000 to April 2016 to evaluate the vaccine schedule, risk factors, serotype distribution, clinical presentation and outcomes of vaccine failure in children vaccinated with the 7-valent (PCV7), 10-valent (PCV10), and 13-valent (PCV13) vaccines. Data sources included MEDLINE, EMBASE, Cochrane library, and references within identified articles. RESULTS: We identified 1742 potential studies and included 20 publications involving 7584 participants in children aged ⩽5year-olds: 5202 received 2 doses followed by a booster in 10 studies, (68.6%), 64 (0.8%) received 3 doses without a booster in 2 studies, and 2318 received a 3+1 schedule (30.6%) in 8 studies. A total of 159 vaccine failure cases were identified, representing 2.1% [95% CI: 1.8-2.4%] of the reported IPD cases. Most studies did not report clinical characteristics or outcomes. Among eight studies reporting comorbidities, 33/77 patients (42.9%) had an underlying condition. The main serotypes associated with vaccine failure were 19F (51/128 cases with known serotype; 39.8%), 6B (33/128; 25.8%), and 4 (10/128; 7.8%). Only five studies reported patient outcomes, with a crude case fatality rate of 2.4% (2/85; 95%CI: 0.3-8.5%). CONCLUSION: Pneumococcal conjugate vaccines have been implemented in national immunisation programmes for more than a decade, yet there are only a few studies reporting vaccine failure. PCV failure is rare, irrespective of vaccine or schedule. Co-morbidity prevalence was high amongst vaccine failure cases but case fatality rate was relatively low. There is a need for more systematic reporting vaccine failure cases in countries with established pneumococcal vaccination programmes

Characteristics and serotype distribution of childhood cases of invasive pneumococcal disease following pneumococcal conjugate vaccination in England and Wales, 2006-14

Background The 7-valent (PCV7) and 13-valent (PCV13) pneumococcal conjugate vaccines are highly effective in preventing invasive pneumococcal disease (IPD) caused by vaccine serotypes. Vaccine failure (vaccine-type IPD after age-appropriate immunisation) is rare. Little is known about the risk, clinical characteristics or outcomes of PCV13 compared to PCV7 vaccine failure. Methods Public Health England conducts IPD surveillance and provides a national reference service for serotyping pneumococcal isolates in England and Wales. We compared the epidemiology, rates, risk factors, serotype distribution, clinical characteristics, and outcomes of IPD in children with PCV13 and PCV7 vaccine failure. Results A total of 163 episodes of PCV failure were confirmed in 161 children over eight years (04 September 2006 to 03 September 2014) in ten birth cohorts. After three vaccine doses, PCV7 and PCV13 failure rates were 0.19/100,000 (95% CI, 0.10-0.33; 57 cases) and 0.66/100,000 (95% CI, 0.44-0.99; 104 cases) vaccinated person-years, respectively. Children with PCV13 failure were more likely to be healthy (87/105 [82.9%] vs. 37/56 [66.1%]; P=0.02), present with bacteremic lower respiratory tract infection (61/105 [58.1%] vs. 11/56 [19.6%]; P<0.001) and develop empyema (41/61 [67.2%] vs. 1/11 [9.1%]; P<0.001) compared to PCV7 failures. Serotypes 3 (n=38, 36.2%) and 19A (n=30, 28.6%) were responsible for most PCV13 failures. Five children died (3.1%; 95% CI, 1.0-7.1%), including four with co-morbidities. Conclusions PCV failure is rare and, compared to PCV7 serotypes, the additional PCV13 serotypes are more likely to cause bacteremic lower respiratory tract infection and empyema in healthy vaccinated children

COVID-19 deaths in children and young people in England, March 2020 to December 2021: An active prospective national surveillance study.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) deaths are rare in children and young people (CYP). The high rates of asymptomatic and mild infections complicate assessment of cause of death in CYP. We assessed the cause of death in all CYP with a positive Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) test since the start of the pandemic in England. METHODS AND FINDINGS: CYP aged <20 years who died within 100 days of laboratory-confirmed SARS-CoV-2 infection between 01 March 2020 and 31 December 2021 in England were followed up in detail, using national databases, surveillance questionnaires, post-mortem reports, and clinician interviews. There were 185 deaths during the 22-month follow-up and 81 (43.8%) were due to COVID-19. Compared to non-COVID-19 deaths in CYP with a positive SARS-CoV-2 test, death due to COVID-19 was independently associated with older age (aOR 1.06 95% confidence interval (CI) 1.01 to 1.11, p = 0.02) and underlying comorbidities (aOR 2.52 95% CI 1.27 to 5.01, p = 0.008), after adjusting for age, sex, ethnicity group, and underlying conditions, with a shorter interval between SARS-CoV-2 testing and death. Half the COVID-19 deaths (41/81, 50.6%) occurred within 7 days of confirmation of SARS-CoV-2 infection and 91% (74/81) within 30 days. Of the COVID-19 deaths, 61 (75.3%) had an underlying condition, especially severe neurodisability (n = 27) and immunocompromising conditions (n = 12). Over the 22-month surveillance period, SARS-CoV-2 was responsible for 1.2% (81/6,790) of all deaths in CYP aged <20 years, with an infection fatality rate of 0.70/100,000 SARS-CoV-2 infections in this age group estimated through real-time, nowcasting modelling, and a mortality rate of 0.61/100,000. Limitations include possible under-ascertainment of deaths in CYP who were not tested for SARS-CoV-2 and lack of direct access to clinical data for hospitalised CYP. CONCLUSIONS: COVID-19 deaths remain extremely rare in CYP, with most fatalities occurring within 30 days of infection and in children with specific underlying conditions

Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS): Prospective, national surveillance, United Kingdom and Ireland, 2020.

Background: Paediatric Multisystem Inflammatory Syndrome temporally associated with SARS-CoV-2 (PIMS-TS), first identified in April 2020, shares features of both Kawasaki disease (KD) and toxic shock syndrome (TSS). The surveillance describes the epidemiology and clinical characteristics of PIMS-TS in the United Kingdom and Ireland. Methods: Public Health England initiated prospective national surveillance of PIMS-TS through the British Paediatric Surveillance Unit. Paediatricians were contacted monthly to report PIMS-TS, KD and TSS cases electronically and complete a detailed clinical questionnaire. Cases with symptom onset between 01 March and 15 June 2020 were included. Findings: There were 216 cases with features of PIMS-TS alone, 13 with features of both PIMS-TS and KD, 28 with features of PIMS-TS and TSS and 11 with features of PIMS-TS, KD and TSS, with differences in age, ethnicity, clinical presentation and disease severity between the phenotypic groups. There was a strong geographical and temporal association between SARS-CoV-2 infection rates and PIMS-TS cases. Of those tested, 14.8% (39/264) children had a positive SARS-CoV-2 RT-PCR, and 63.6% (75/118) were positive for SARS-CoV-2 antibodies. In total 44·0% (118/268) required intensive care, which was more common in cases with a TSS phenotype. Three of five children with cardiac arrest had TSS phenotype. Three children (1·1%) died. Interpretation: The strong association between SARS-CoV-2 infection and PIMS-TS emphasises the importance of maintaining low community infection rates to reduce the risk of this rare but severe complication in children and adolescents. Close follow-up will be important to monitor long-term complications in children with PIMS-TS. Funding: PHE

Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS): Prospective, national surveillance, United Kingdom and Ireland, 2020

Background: Paediatric Multisystem Inflammatory Syndrome temporally associated with SARS-CoV-2 (PIMS-TS), first identified in April 2020, shares features of both Kawasaki disease (KD) and toxic shock syndrome (TSS). The surveillance describes the epidemiology and clinical characteristics of PIMS-TS in the United Kingdom and Ireland. Methods: Public Health England initiated prospective national surveillance of PIMS-TS through the British Paediatric Surveillance Unit. Paediatricians were contacted monthly to report PIMS-TS, KD and TSS cases electronically and complete a detailed clinical questionnaire. Cases with symptom onset between 01 March and 15 June 2020 were included. Findings: there were 216 cases with features of PIMS-TS alone, 13 with features of both PIMS-TS and KD, 28 with features of PIMS-TS and TSS and 11 with features of PIMS-TS, KD and TSS, with differences in age, ethnicity, clinical presentation and disease severity between the phenotypic groups. There was a strong geographical and temporal association between SARS-CoV-2 infection rates and PIMS-TS cases. Of those tested, 14.8% (39/264) children had a positive SARS-CoV-2 RT-PCR, and 63.6% (75/118) were positive for SARS-CoV-2 serology. In total 44·0% (118/268) required intensive care, which was more common in cases with a TSS phenotype. Three of five children with cardiac arrest had TSS phenotype. Three children (1·1%) died. Interpretation: the strong association between SARS-CoV-2 infection and PIMS-TS emphasises the importance of maintaining low community infection rates to reduce the risk of this rare but severe complication in children and adolescents. Close follow-up will be important to monitor long-term complications in children with PIMS-T

Vitamin D mobile healthcare applications for consumer use - are they any good?

Introduction: Members of the public interested in changing their health behaviour and comfortable with use of social media can download and purchase commercially developed lifestyle and or healthcare computer software. This is facilitated by the increase in technologically advanced, often elegantly designed, small screen portable in-built computerised systems on mobile smart-phones. Aims: With increasing awareness of use of Vitamin D for improved health outcomes, the aims for this study were to identify and evaluate any Vitamin D mobile smart-phone healthcare applications (apps) available for public or consumer use. Methods: Incorporating a multi-phase mixed study design, in phase one Vitamin D apps on mobile smart-phones were identified and categorised by consensus using the Delphi technique. In phase two a database search was undertaken to gain an understanding of research undertaken on use of healthcare apps and any evaluation of outcomes. In phase three a modified validated mobile applications rating scale (MARS) was utilised to evaluate the apps identified in phase one. Each app that provided some health information was assigned objective scores for information quality, and subjective quality and app specific rating scores. Discussion: No Vitamin D apps were identified where evaluation in research trial settings has shown significant beneficial health outcomes. However the literature search helped to identify criteria that form a potential checklist for any future development of a Vitamin D app for consumer use. Use of the modified MARS, with scores assigned for validated information quality criteria, identified two apps which were rated highly but with use restricted to medical teams, and seven apps focusing on dietary intake. Results: Nine apps were identified supporting some level of healthcare delivery and assigned MARS scores. Seven of these apps focused primarily on Vitamin D nutritional support. There were no high quality Vitamin D apps identified that could help consumers with decision on Vitamin D supplementation

Risk of invasive pneumococcal disease in children with sickle cell disease in the era of conjugate vaccines: a systematic review of the literature.

Pneumococcal conjugate vaccines (PCVs) are highly effective in preventing invasive pneumococcal diseases (IPD) in children, including those with sickle cell disease (SCD). A systematic review of the English literature published between 2000 and 2017 was undertaken to evaluate the serotype distribution, clinical presentation and outcomes of IPD in children with SCD in PCV programmes. We identified 475 potential studies and included 16 publications, involving 9438 children up to 22 years of age with SCD and 182 IPD episodes (prevalence, 1·9%. 95% confidence interval [CI], 1·7-2·2%). Septicaemia was the most prevalent clinical presentation (84/137; 61%) followed by lower respiratory tract infection (39/137; 29%) and meningitis (12/137, 9%). More than half the serotypes associated with IPD (88/148; 59·5%) were not included in the 13-valent PCV; of these, 54% (44/82) were due to serogroup 15. The crude case fatality rate was 11·5% (21/182 cases; 95% CI, 7·3-17·1%). Most cases of IPD in children with SCD were due to serotypes that are not included in any of the licensed PCVs. IPD in children with SCD remains associated with high morbidity and mortality, highlighting the importance of strict adherence to daily penicillin prophylaxis. Until a serotype-independent pneumococcal vaccine becomes available, higher-valent PCVs should include serogroup 15 to protect this highly vulnerable group of children

Childhood Deaths Attributable to Invasive Pneumococcal Disease in England and Wales, 2006–2014

Background: Pneumococcal conjugate vaccines (PCV) are highly effective in preventing invasive pneumococcal disease (IPD) but deaths due to IPD still occur. We aimed to describe children who died of IPD since PCV introduction in England and Wales. Methods: Public Health England conducts enhanced IPD surveillance in England and Wales. IPD cases in PCV-eligible children aged <5 years (born since 04 September 2004 and diagnosed between 04 September 2006 and 03 September 2014) were actively followed-up by postal questionnaires and, for fatal cases, detailed information was requested prospectively from multiple sources. Results: During the 8-year period, there were 3,146 IPD cases and 150 IPD-related deaths (case fatality rate, 4.8%). Overall, 132 isolates from fatal cases were serotyped (88%) and 35 distinct serotypes were identified, with no serotype predominance. Most deaths occurred in <1 year-olds (88/150, 59%) and one year-olds (36/150, 24%). One-third (53/150, 35%) had a known risk factor for IPD. Clinical presentation varied with age but not by serotypes in the different conjugate vaccines. Meningitis was diagnosed in nearly half the fatal cases (71/150, 47%). IPD-related mortality-rate declined after PCV7 introduction from 1.25/100,000 children in 2006/07 to 0.60/100,000 in 2009/10, with a further reduction following PCV13 introduction from April 2010 to 0.39/100,000 in 2013/14 (14 deaths; IRR, 0.31; 95%CI, 0.16-0.61; P=0.0003), when most deaths were due to non-vaccine serotypes or in neonates. Conclusions: Most fatal IPD cases are currently not vaccine-preventable. Additional strategies will be required to reduce childhood pneumococcal deaths in countries with established pneumococcal vaccination programmes