Durability of Vaccine-Induced and Natural Immunity Against COVID-19: A Narrative Review.

Vaccines developed against SARS-CoV-2 have proven to be highly effective in preventing symptomatic infection. Similarly, prior infection with SARS-CoV-2 has been shown to provide substantial protection against reinfection. However, it has become apparent that the protection provided to an individual after either vaccination or infection wanes over time. Waning protection is driven by both waning immunity over time since vaccination or initial infection, and the evolution of new variants of SARS-CoV-2. Both antibody and T/B-cells levels have been investigated as potential correlates of protection post-vaccination or post-infection. The activity of antibodies and T/B-cells provide some potential insight into the underlying causes of waning protection. This review seeks to summarise what is currently known about the waning of protection provided by both vaccination and/or prior infection, as well as the current information on the respective antibody and T/B-cell responses.

Hepatitis B surface antigen prevalence and the rates of mother-to-child transmission of hepatitis B virus after the introduction of infant vaccination programs in South East Asia and Western Pacific regions: a systematic review.

OBJECTIVES: Infant vaccination against the hepatitis B virus began in the World Health Organization South East Asia Region and the Western Pacific Region between 1983 and 2016. This systematic review examined the seroprevalence of hepatitis B surface antigen (HBsAg) in children and the rate of mother-to-child transmission (MTCT) in these regions between 1990 and 2020. METHODS: MEDLINE and EMBASE were searched for articles published between January 1990 and September 2020, which reported seroprevalence of HBsAg in children aged 0-15 years and/or the rate of MTCT in the South East Asia Region and Western Pacific Region. A pragmatic review identified supporting information. This review was registered in the International Prospective Register of Systematic Reviews (#CRD42020211707). RESULTS: Of 115 included studies, 77 (24 countries) reported HBsAg prevalence, and 38 (nine countries) reported MTCT. The seroprevalence of HBsAg ranged between 0.0% and 27.4%, with a decreasing trend over time in each country. MTCT rates were 0.0-5.2% in infants of mothers who are hepatitis B e antigen-negative and 2.7-53.0% in infants of mothers who are hepatitis B e antigen-positive. CONCLUSION: After the introduction of infant hepatitis B virus vaccination programs, the countries in South East Asia Region and Western Pacific Region observed a reduction in HBsAg seroprevalence in children. Nevertheless, the risk of MTCT persists, emphasizing the importance of antenatal screening to identify high-risk pregnancies.

Association of COPD exacerbations and acute cardiovascular events: a systematic review and meta-analysis.

BACKGROUND: The majority of patients with chronic obstructive pulmonary disease (COPD) suffer from comorbid cardiovascular (CV) disease. Accumulating evidence suggests a temporal association between COPD exacerbations and acute CV events, possibly due to lung hyperinflation, increased hypoxemia and systemic inflammation. The aims of the study were to estimate the risk of (1) acute CV events [acute myocardial infarction (AMI), CV-related death] or stroke in the months following a COPD exacerbation and (2) COPD exacerbation in the months following an acute CV event. METHODS: A systematic literature review of observational studies published since 2000 was conducted by searching literature databases (Medline and Embase). Studies were eligible if conducted in adults with COPD, exposed to either COPD exacerbation or acute CV events, with outcomes of acute CV events or COPD exacerbation reported. Studies were appraised for relevance, bias and quality. Meta-analyses, using random-effect models, were performed for each outcome of interest, thus providing a pooled relative risk (RR) and its 95% confidence interval. RESULTS: Eight studies were identified, of which seven were used for the meta-analyses examining the risk of CV events 1-3 months after an exacerbation compared with none. For stroke (six studies), RR was 1.68 (95% CI = 1.19-2.38). For AMI (six studies), RR was 2.43 (95% CI = 1.40-4.20). No studies exploring risk of exacerbation following an acute CV event were identified. CONCLUSION: This meta-analysis identified a markedly increased risk of stroke or AMI within a relatively short period of time following a COPD exacerbation. Although the underlying mechanisms are not fully elucidated, patients with COPD should be monitored for risk of CV outcomes after exacerbations. In addition, preventing exacerbations may decrease the risk of subsequent acute CV events. REGISTRATION: The study protocol was published via PROSPERO: International Prospective Register of Systematic Reviews (#CRD42020211055).

The Underestimated and Overlooked Burden of Diarrhea and Constipation in Cancer Patients.

PURPOSE OF REVIEW: This review aims to summarize and discuss the diverse causes of two major gastrointestinal dysfunction symptoms, diarrhea and constipation, in cancer patients. We also discuss short- and long-term clinical, economic, and humanistic consequences, including the impact on cancer treatment regimens and patient quality of life, highlighting the limitations of the literature. RECENT FINDINGS: Diarrhea and constipation as a result of cancer and its treatment can risk the success of anti-cancer therapies by requiring treatment delay or withdrawal, and imposes a substantial humanistic burden in patients with cancer. Despite its importance and frequency, gastrointestinal side effects may be overlooked due to the focus on cancer treatment, and the impact on patients may be underestimated. Additionally, the burden reported may not fully reflect current cancer management, particularly the true impact of economic consequences. A full understanding of the burden of diarrhea and constipation in patients with cancer is required, including broad evaluation of clinical considerations, the patient experience, and an updated assessment of economic burden. This would improve caregivers' appreciation of the impact of gastrointestinal dysfunction and aid the prioritization of future research efforts.

Risk of malignancy in patients with systemic lupus erythematosus: Systematic review and meta-analysis.

BACKGROUND: Malignancy is a potential comorbidity in patients with systemic lupus erythematosus (SLE). However, risk by malignancy type remains to be fully elucidated. We evaluated the risk of malignancy type in SLE patients in a systematic review and meta-analysis. METHODS: MEDLINE and EMBASE were searched from inception to July 2018 to identify observational studies that evaluated malignancy risk in adult SLE patients compared with the general population. Random-effects models were used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Heterogeneity was quantified using the I2 test. FINDINGS: Forty-one studies reporting on 40 malignancies (one overall, 39 site-specific) were included in the meta-analysis. The pooled RR for all malignancies from 3694 events across 80 833 patients was 1.18 (95% CI: 1.00-1.38). The risk of 24 site-specific malignancies (62%) was increased in SLE patients. For malignancies with ≥6 studies, non-Hodgkin lymphoma and Hodgkin lymphoma risk was increased >3-fold; myeloma and liver >2-fold; cervical, lung, bladder, and thyroid ≥1.5-fold; stomach and brain >1.3-fold. The risk of four malignancies (breast, uterine, melanoma, prostate) was decreased, whereas risk of 11 other malignancies did not differ between SLE patients and the general population. Heterogeneity ranged between 0% and 96%, and 63% were non-significant. INTERPRETATION: The risk of overall and some site-specific malignancies is increased in SLE compared with the general population. However, the risk for some site-specific malignancies is decreased or did not differ. Further examination of risk profiles and SLE patient phenotypes may support guidelines aimed at reducing malignancy risk. FUNDING: AstraZeneca. SYSTEMATIC REVIEW REGISTRATION: PROSPERO number: CRD42018110433.

The risk of infections in adult patients with systemic lupus erythematosus: systematic review and meta-analysis.

OBJECTIVES: We conducted a systematic review and meta-analysis to determine the magnitude of infection risk in patients with SLE and evaluate the effect of general and SLE-related factors on infection risk. METHODS: We searched MEDLINE and Embase from inception to July 2018, screening for observational studies that evaluated infection risk in patients with SLE compared with the general population/healthy controls. Outcomes of interest included overall severe infection, herpes zoster infection/reactivation, opportunistic infections, pneumonia and tuberculosis. Random-effects models were used to calculate pooled risk ratios (RRs) for each type of infection. Sensitivity analysis assessed the impact of removing studies with high risk of bias. RESULTS: Eleven retrospective or prospective cohort studies were included in the meta-analysis: overall severe infection (n = 4), pneumonia (n = 6), tuberculosis (n = 3) and herpes zoster (n = 2). Pooled RRs for overall severe infection significantly increased for patients with SLE compared with the general population/healthy controls [RR 2.96 (95% CI 1.28, 6.83)]. Pooled RRs for pneumonia, herpes zoster and tuberculosis showed significantly increased risk compared with the general population/healthy controls [RR 2.58 (1.80, 3.70), 2.50 (2.36, 2.65) and 6.11 (3.61, 10.33), respectively]. Heterogeneity and evidence of publication bias were present for all analyses, except herpes zoster. Sensitivity analyses confirmed robustness of the results. CONCLUSION: Patients with SLE have significantly higher risk of infection compared with the general population/healthy controls. Efforts to strengthen strategies aimed at preventing infections in SLE are needed. PROTOCOL REGISTRATION: PROSPERO number: CRD42018109425.

Systemic lupus erythematosus; stroke and myocardial infarction risk: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the risk of stroke and myocardial infarction (MI) in adult patients with systemic lupus erythematosus (SLE) through a systematic review and meta-analysis. METHODS: We searched MEDLINE and EMBASE from inception to May 2020 to identify observational studies (cohort and cross-sectional) that evaluated risk of stroke and MI in adult patients with SLE compared with the general population or healthy controls. Studies were included if they reported effect-size estimates that could be used for calculating pooled-effect estimates. Random-effects models were used to calculate pooled risk ratios (RRs) and 95% CIs for stroke and MI. Heterogeneity quantified by the I2 test and sensitivity analyses assessed bias. RESULTS: In total, 26 studies were included in this meta-analysis: 14, 5 and 7 studies on stroke, MI and both stroke and MI, respectively. The pooled RR for ischaemic stroke was 2.18 (95% CI 1.78 to 2.67; I2 75%), intracerebral haemorrhage 1.84 (95% CI 1.16 to 2.90; I2 67%), subarachnoid haemorrhage 1.95 (95% CI 0.69 to 5.52; I2 94%), composite stroke 2.13 (95% CI 1.73 to 2.61; I2 88%) and MI 2.99 (95% CI 2.34 to 3.82; I2 85%). There was no evidence for publication bias, and sensitivity analyses confirmed the robustness of the results. CONCLUSIONS: Overall, patients with SLE were identified to have a twofold to threefold higher risk of stroke and MI. Future research on the interaction between known SLE-specific modifiable risk factors and risk of stroke and MI to support development of prevention and treatment strategies are needed. PROSPERO REGISTRATION NUMBER: CRD42018098690.

Single-inhaler triple therapy in patients with chronic obstructive pulmonary disease: a systematic review.

BACKGROUND: Guidelines recommend that treatment with a long-acting ß2 agonist (LABA), a long-acting muscarinic antagonist (LAMA), and inhaled corticosteroids (ICS), i.e. triple therapy, is reserved for a select group of symptomatic patients with chronic obstructive pulmonary disease (COPD) who continue to exacerbate despite treatment with dual therapy (LABA/LAMA). A number of single-inhaler triple therapies are now available and important clinical questions remain over their role in the patient pathway. We compared the efficacy and safety of single-inhaler triple therapy to assess the magnitude of benefit and to identify patients with the best risk-benefit profile for treatment. We also evaluated and compared study designs and population characteristics to assess the strength of the evidence base. METHODS: We conducted a systematic search, from inception to December 2018, of randomised controlled trials (RCTs) of single-inhaler triple therapy in patients with COPD. The primary outcome was the annual rate of moderate and severe exacerbations. RESULTS: We identified 523 records, of which 15 reports/abstracts from six RCTs were included. Triple therapy resulted in the reduction of the annual rate of moderate or severe exacerbations in the range of 15-52% compared with LAMA/LABA, 15-35% compared to LABA/ICS and 20% compared to LAMA. The patient-based number needed to treat for the moderate or severe exacerbation outcome ranged between approximately 25-50 (preventing one patient from having an event) and the event-based number needed to treat of around 3-11 (preventing one event). The absolute benefit appeared to be greater in patients with higher eosinophil counts or historical frequency of exacerbations and ex-smokers. In the largest study, there was a significantly higher incidence of pneumonia in the triple therapy arm. There were important differences in study designs and populations impacting the interpretation of the results and indicating there would be significant heterogeneity in cross-trial comparisons. CONCLUSION: The decision to prescribe triple therapy should consider patient phenotype, magnitude of benefit and increased risk of adverse events. Future research on specific patient phenotype thresholds that can support treatment and funding decisions is now required from well-designed, robust, clinical trials. TRIAL REGISTRATION: PROSPERO #CRD42018102125 .