Trivalent inactivated influenza vaccine is not associated with sickle cell crises in children

Guarding Health: A Comprehensive Review of Nosocomial Infections in Sickle Cell Anemia, a Multifaceted Approach to Prevention

This comprehensive review explores the complex dynamics of nosocomial infections in individuals with sickle cell anemia (SCA) and advocates for a collaborative strategy to enhance prevention. SCA patients, marked by compromised immunity and susceptibility to infections, face unique challenges that necessitate tailored preventive measures. The review underscores the importance of vaccination, antibiotic prophylaxis, education, and environmental hygiene in mitigating the risk of nosocomial infections. Addressing socioeconomic factors, healthcare system limitations, patient-related issues, and cultural considerations is imperative for effective prevention. The call to action emphasizes the pivotal roles of healthcare professionals, policymakers, researchers, and community engagement in implementing targeted interventions. By fostering a collective effort, this review envisions an improved landscape for infection prevention in SCA patients, enhancing their overall health outcomes and quality of life.

Influenza Vaccination Receipt in Pediatric Patients With Cancer or Sickle Cell Disease

BACKGROUND

Influenza causes greater morbidity in children with cancer or sickle cell disease (SCD). Literature on influenza vaccination receipt for these populations is limited in low-vaccination states. Outpatient interventions improve vaccine receipt but isolated inpatient interventions remain unstudied.

PROCEDURE

We reviewed influenza vaccine receipt of children with cancer or SCD treated at Children's Healthcare of Atlanta during three influenza seasons. We implemented a clinical decision support intervention during an influenza season and compared influenza vaccine receipt preintervention and postintervention among admitted children.

RESULTS

The oncology cohort (N=1548, 60% to 62%) and the SCD cohort (N=2549, 61% to 65%) had similar-to-higher vaccination receipt to the United States (58% to 64%, P =0.01 to 0.79) and Georgia (51% to 56%, P <0.01). The intervention did not significantly improve vaccination receipt for admitted children with cancer (40% vs. 56%, P =0.05 to 0.88) or SCD (44% vs. 56%, P =0.01). Regression modeling also found no significant increase in vaccine receipt (hematologic malignancy: 0.8 [0.73 to 0.98], solid tumor: 0.9 [0.80 to 1.90], central nervous system tumor: 0.9 [0.71 to 1.14], SCD: 0.9 [0.85 to 0.99]).

CONCLUSIONS

Children with cancer and SCD have similar-to-greater influenza vaccination receipt compared with Georgia and the United States. An inpatient intervention did not significantly improve influenza vaccine receipt in these patient cohorts. Future studies are needed to identify alternative approaches to improving vaccine receipt in these cohorts.

Safety of coronavirus disease 2019 vaccines in 213 adult patients with sickle cell disease

Given the lack of information about safety of the COVID-19 vaccines for sickle cell disease (SCD) patients, we sought to determine whether COVID-19 vaccine was associated with subsequent hospital admission for vaso-occlusive events (VOEs). We included 402 patients with SCD, including 88 regularly transfused. As of July 31, 2021, 213 (53.0%) of them had received a least one dose of COVID vaccine (Pfizer 93.0%). We showed similar risk of hospital admission for a VOE among vaccinated patients (whether transfused or not) and among a control group of non-vaccinated patients matched for age, sex and genotype.

Maintenance of a High Influenza Vaccination Rate and Improvement in Health Outcomes in a Pediatric Sickle Cell Disease Clinic

BACKGROUND

Children with sickle cell disease (SCD) are at high-risk of complications from influenza and should receive an influenza vaccination seasonally. Despite this recommendation, vaccination rates remain suboptimal. Boston Medical Center (BMC) previously achieved high influenza vaccination rates among its pediatric patients with SCD. The purpose of this study was to determine whether this high vaccination rate has been maintained and whether it has influenced outcome measures.

PATIENTS AND METHODS

A retrospective chart review was conducted in the hematology clinic at an urban, academic medical center. Fisher's exact test and the independent samples t test were used to determine if there were any significant differences in characteristics between patients with influenza and patients without influenza, as well as between vaccinated and unvaccinated patients. Influenza vaccination rate, influenza-related hospitalization rate, and influenza-positive rate were collected and compared with reported rates.

RESULTS

Data from 124 pediatric patients with SCD were examined. The influenza vaccination rate for pediatric patients with SCD at BMC (90.32%) was higher than previous studies that were not conducted at BMC, while BMC's influenza-related hospitalization rate (0) and influenza-positive rate (4.84%) were lower than other studies. Subjects who contracted influenza were younger than those who did not (4.67 vs. 10.03 y, P=0.005).

CONCLUSIONS

BMC has maintained a high influenza vaccination rate among pediatric patients with SCD. BMC's vaccination strategy has been successful at improving outcome measures including rates of influenza and influenza hospitalizations without requiring additional staff. Such efforts should be replicated at other centers.

Safety of vaccines used for routine immunization in the United States: An updated systematic review and meta-analysis

BACKGROUND

Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.

METHODS

We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).

RESULTS

Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of  intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).

CONCLUSIONS

Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

Influenza vaccine effectiveness and disease burden in children and adolescents with sickle cell disease: 2012-2017

BACKGROUND

Data are limited on the burden of influenza and seasonal influenza vaccine effectiveness (VE) in children with sickle cell disease (SCD).

METHODS

We used a prospectively collected clinical registry of SCD patients 6 months to 21 years of age to determine the influenza cases per 100 patient-years, vaccination rates, and a test-negative case-control study design to estimate influenza VE against medically attended laboratory-confirmed influenza infection. Influenza-positive cases were randomly matched to test-negative controls on age and influenza season in 1:1 ratio. We used adjusted logistic regression models to compare odds ratio (OR) of vaccination in cases to controls. We calculated VE as [100% × (1 - adjusted OR)] and computed 95% confidence intervals (CIs) around the estimate.

RESULTS

There were 1037 children with SCD who were tested for influenza, 307 children (29.6%) had at least one influenza infection (338 infections, incidence rate 3.7 per 100 person-years; 95% CI, 3.4-4.1) and 56.2% of those tested received annual influenza vaccine. Overall VE pooled over five seasons was 22.3% (95% CI, -7.3% to 43.7%). Adjusted VE estimates ranged from 39.7% (95% CI, -70.1% to 78.6%) in 2015/2016 to -5.9% (95% CI, -88.4% to 40.4%) in the 2016/17 seasons. Influenza VE varied by age and was highest in children 1-5 years of age (66.6%; 95% CI, 30.3-84.0). Adjusted VE against acute chest syndrome during influenza infection was 39.4% (95% CI, -113.0 to 82.8%).

CONCLUSIONS

Influenza VE in patients with SCD varies by season and age. Multicenter prospective studies are needed to better establish and monitor influenza VE among children with SCD.

Significance of electronic health records: A comparative study of vaccination rates in patients with sickle cell disease

OBJECTIVE

In this study, we investigated the influence of electronic health records (EHR) and electronic vaccination schedule applications on the vaccination status of patients who were admitted to our Center for the treatment of sickle cell disease (SCD).

METHODS

The vaccination status against influenza and pneumococcus infection was determined in 93 patients who were admitted to the hematology outpatient clinic, Baskent University Adana Hospital from April 2004 to March 2009. The vaccination status was then re-evaluated following establishment of EHR and electronic vaccination schedules in 2012.

RESULTS

Of the 93 patients with SCD 21.5% (n = 20) were vaccinated against pneumococcus and 21.5% (n = 20) were regularly vaccinated against influenza. When the vaccination rates of 59 of 93 patients who presented for their regular control examinations were analyzed following establishment of EHR and vaccination schedules in 2012, these rates were 49.2% (n = 29) and 50.8% (n = 30) for influenza and pneumococcus, respectively, after EHR; there were 23.7% (n = 14) and 20.3% (n = 12), respectively, before EHR. A statistically significant difference was found between the vaccination rates before and after EHR (p < 0.05).

CONCLUSION

Although viral and bacterial infections are life-threatening health problems in patients with SCD, the vaccination rates were low in high-risk patients. However, these rates increased after application of electronic vaccination schedules.

Preventive Care Delivery to Young Children With Sickle Cell Disease

Preventive services can reduce the morbidity of sickle cell disease (SCD) in children but are delivered unreliably. We conducted a retrospective cohort study of children aged 2 to 5 years with SCD, evaluating each child for 14 months and expecting that he/she should receive ≥75% of days covered by antibiotic prophylaxis, ≥1 influenza immunization, and ≥1 transcranial Doppler ultrasound (TCD). We used logistic regression to quantify the relationship between ambulatory generalist and hematologist visits and preventive services delivery. Of 266 children meeting the inclusion criteria, 30% consistently filled prophylactic antibiotic prescriptions. Having ≥2 generalist, non-well child care visits or ≥2 hematologist visits was associated with more reliable antibiotic prophylaxis. Forty-one percent of children received ≥1 influenza immunizations. Children with ≥2 hematologist visits were most likely to be immunized (62% vs. 35% among children without a hematologist visit). Only 25% of children received ≥1 TCD. Children most likely to receive a TCD (42%) were those with ≥2 hematologist visits. One in 20 children received all 3 preventive services. Preventive services delivery to young children with SCD was inconsistent but associated with multiple visits to ambulatory providers. Better connecting children with SCD to hematologists and strengthening preventive care delivery by generalists are both essential.

Vaccinations in sickle cell disease: An audit of vaccination uptake in sickle cell patients attending Newham University Hospital

AIMS

To assess the level of adherence of patients with sickle cell disease to the advised vaccination schedule with respect to the Sickle Cell Society guidelines on vaccination [1,2].

METHODS

A retrospective audit of patients' vaccination records was carried out between July 2012 and June 2013 on a sample of 80 patients over the age of 16, who attended Newham University Hospital accident and emergency (A&E) department with a presenting complaint coded as "sickle cell". A re-audit was conducted from January 2014 to December 2014 to close the audit loop. Chi-squared and Fisher's exact tests were used to compare the results.

RESULTS

The initial audit and re-audit identified 80 and 86 patients, respectively. Only 2 (2012-2013) and 7 (2014) patients had a complete up-to-date vaccination profile. 24 (30%) patients had up-to-date influenza vaccination, increasing to 43 (50%, P=0.0062) when re-audited. 33 (41%) had current pneumococcal vaccinations, increasing to 38 (44%, P=0.7874). Uptake rates for vaccinations against Meningococcal group C (MenC), Haemophilus influenzae B (HiB) and Hepatitis B virus (HBV) were under 31% in both audits. A significant improvement in vaccination rate was observed for all vaccinations except pneumococcal and HBV.

CONCLUSIONS

Although significant improvements have been demonstrated, this audit shows a low level of adherence to the advised vaccination schedule. The study also highlighted a shortfall in appropriate record keeping, reducing the potential for detailed conclusions being drawn in relation to the childhood vaccinations against MenC, HiB and HBV. Implementation of a new database of vaccination history, raising GP awareness and patient education seminars has lead to a significant improvement in vaccination rates locally and the authors hope that this may be replicated in other centres. There may be potential to increase rates further by administering vaccinations to inpatients.

Potential Impact of Co-Infections and Co-Morbidities Prevalent in Africa on Influenza Severity and Frequency: A Systematic Review

Infectious diseases and underlying medical conditions common to Africa may affect influenza frequency and severity. We conducted a systematic review of published studies on influenza and the following co-infections or co-morbidities that are prevalent in Africa: dengue, malaria, measles, meningococcus, Pneumocystis jirovecii pneumonia (PCP), hemoglobinopathies, and malnutrition. Articles were identified except for influenza and PCP. Very few studies were from Africa. Sickle cell disease, dengue, and measles co-infection were found to increase the severity of influenza disease, though this is based on few studies of dengue and measles and the measles study was of low quality. The frequency of influenza was increased among patients with sickle cell disease. Influenza infection increased the frequency of meningococcal disease. Studies on malaria and malnutrition found mixed results. Age-adjusted morbidity and mortality from influenza may be more common in Africa because infections and diseases common in the region lead to more severe outcomes and increase the influenza burden. However, gaps exist in our knowledge about these interactions.

The Vaccine Safety Datalink: successes and challenges monitoring vaccine safety

The Vaccine Safety Datalink (VSD) is a collaborative project between the Centers for Disease Control and Prevention (CDC) and 9 health care organizations. Established in 1990, VSD is a vital resource informing policy makers and the public about the safety of vaccines used in the United States. Large linked databases are used to identify and evaluate adverse events in over 9 million individuals annually. VSD generates rapid, important safety assessments for both routine vaccinations and emergency vaccination campaigns. VSD monitors safety of seasonal influenza vaccines in near-real time, and provided essential information on the safety of influenza A (H1N1) 2009 monovalent vaccine during the recent pandemic. VSD investigators have published important studies demonstrating that childhood vaccines are not associated with autism or other developmental disabilities. VSD prioritizes evaluation of new vaccines; searches for possible unusual health events after vaccination; monitors vaccine safety in pregnant women; and has pioneered development of biostatistical research methods.

Transgenic sickle cell disease mice have high mortality and dysregulated immune responses after vaccination

BACKGROUND

Children with sickle cell disease (SCD) are susceptible to recurrent infections, which are often life threatening and necessitate frequent vaccinations. Given the altered baseline immunity and proinflammatory state associated with SCD, we sought to determine the relative safety and efficacy of vaccination in transgenic SCD mice.

METHODS

Eight-week-old SCD mice were vaccinated with ovalbumin and aluminum hydroxide weekly for 3 wk by the intraperitoneal or intramuscular route. One week after the third vaccination, serum cytokines/chemokines, immunoglobulins, and bronchoalveolar lavage fluid cytokines were measured.

RESULTS

Only SCD mice were prone to mortality associated with vaccination, as 40% of the animals died after the intraperitoneal vaccinations and 50% died after the intramuscular vaccinations. Serum IgG2b and IgM were significantly lower in SCD mice than in C57BL/6 mice after vaccination, but ovalbumin-specific IgE was significantly higher. Serum interleukin (IL)-1α, IL-2, IL-5, macrophage inflammatory protein 1α, and granulocyte macrophage-colony stimulating factor were significantly lower in SCD mice than in C57BL/6 mice after vaccination, whereas bronchoalveolar lavage fluid IL-1β and IL-6 were increased.

CONCLUSION

Mice with SCD appear to have a dysregulated immune response to vaccination. Thus, the relative safety and immunogenicity of vaccination should be studied in greater detail in the context of SCD.

Trivalent inactivated influenza vaccine is not associated with sickle cell hospitalizations in adults from a large cohort

We evaluated the risk of hospitalization for sickle cell crisis (SCC) following influenza vaccination (trivalent inactivated vaccine, TIV) in adults with sickle cell disease. The cohort consisted of all adults aged 18years and older who had a diagnosis of sickle cell disease in the Vaccine Safety Datalink from 1991 to 2006. The outcome measure was any hospitalization for SCC with the main exposure being influenza vaccine. We used a self controlled case series design to compare the incidence rates of hospitalization for SCC during the exposed and unexposed periods after TIV. No significant association between influenza vaccination and hospitalization for sickle cell crisis was found (IRR ratio 0.92, 95% confidence limits 0.66-1.28). These results provide evidence that the seasonal influenza vaccine is safe as recommended in adults who are at high risk for complications of influenza sequelae due to sickle cell disease.