scholarly journals Effectiveness of COVID-19 vaccines against delta variant (B.1.617.2): A meta-analysis

Author(s):  
Rashidul Alam Mahumud ◽  
Mohammad Afshar Ali ◽  
Satyajit Kundu ◽  
Md Ashfikur Rahman ◽  
Joseph Kihika Kamara ◽  
...  

Abstract ObjectivesThe highly transmissible COVID-19 delta variant (DV) has contributed to the surge in cases and has now been exacerbated the worldwide public health crisis. Several COVID-19 vaccines play a significant role in a high degree of protection against DV. The primary purpose of this meta-analysis is to estimate the pooled effectiveness of the COVID-19 vaccines against DV in terms of risk ratio (RR) among fully vaccinated, compared to unvaccinated populations.MethodsWe carried out a systematic review with meta-analysis of original studies focused on COVID-19 vaccines effectiveness of COVID-19 vaccines against B.1.617.2 clinical perspective among fully COVID-19 vaccinated populations, compared to placebo (unvaccinated populations), published before September 30, 2021. Eleven studies containing data of 17.2 million participants were identified and included in our study. Pooled estimates of COVID-19 vaccines effectiveness (i.e., risk ratio, RR) against delta variant with 95% confidence intervals were assessed using random-effect models. Publication bias was assessed using Egger's regression test and funnel plot to investigate potential sources of heterogeneity and identify any differences in study design.ResultsA total population of 17.2 million (17,200,341 peoples) were screened for the COVID-19 vaccines' effectiveness against delta variant. We found 61.13% of study population were fully vaccinated with 2-dose of COVID-19 vaccines. Weighted pooled incidence of COVID-19 infection was more than double (20.07%) among unvaccinated populations, compared to the fully vaccinated population (8.16%). Overall, the effectiveness of COVID-19 vaccine against DV was 85% (RR = 0.15, 95% CI: 0.07-0.31). The effectiveness of COVID-19 vaccines varied slidably by study designs, 87% (RR = 0.13, 95% CI: 0.06-0.30) and 84% (RR = 0.16, 95% CI:0.02, 1.64) for cohort and case-control studies, respectively. ConclusionEffectiveness COVID-19 vaccines were noted to offer higher protection against delta variant among populations who received two vaccine doses compared with unvaccinated populations. This finding would help efforts to maximise vaccine coverage (i.e., at least 60 to 70% of the population) with two doses among vulnerable populations to have herd immunity to breat the chain of transmission and gain greater overall population protection more rapidly.

2020 ◽  
Vol 9 (1) ◽  
pp. 41-50
Author(s):  
Lao Duc Thuan ◽  
Truong Kim Phuong

Purpose: Death-associated protein kinase (DAPK or DAPK1) is an important tumor suppressor protein that involved in the regulation of cell activities. The aberrant methylation of DAPK promoter has been reported in patients with cervical cancer. However, the association between of DAPK1 and cervical cancer was not always unification, in previous studies. Therefore, in current study, a meta-analysis was performed for association of between DAPK gene’s promoter hypermethylated and cervical cancer. Methods: A systematic literature analysis was conducted based on the previous studies published in PubMed, PubMed Central (NCBI), Google by using following keywords: cervical cancer, cervical carcinoma, Methylation, by the end of January, 2018. The association between DAPK promoter methylation and cervical cancer was evaluated by odds ratio (ORs) and 95% confidence intervals (CI). To evaluate the potential sources of heterogeneity, the meta-regression analysis and subgroup analysis were conducted. Results: A total of 21 case-control studies which relevant to the association between DAPK1 gene’s promoter methylation frequency and cervical cancer, that including 1600 cancer cases and 1011 control cases (non-cancerous cases). The analysis results indicated that the characteristic of candidate gene’s promoter methylation increased the cervical cancer risk through the calculation of OR value (OR = 21.25; 95% CI = 8.73 – 52.97; p < 0.001; Random effect model). The association between DAPK1 gene’s promoter hypermethylation was confirmed in all the subgroups analyses, including materials and assays methods, ethnicity. Furthermore, this association is higher in cervical squamous cell carcinoma than cervical adenocarcinoma and is a characteristic of late-stage disease. Conclusion: The hypermethylated DAPK1 gene’s promoter was also one of etiological factor, lead to the cervical tumorigenesis.


2021 ◽  
Author(s):  
Long-Shan Yang ◽  
Guang-Xiao Meng ◽  
Zi-Niu Ding ◽  
Lun-Jie Yan ◽  
Sheng-Yu Yao ◽  
...  

Abstract Background Glycemic index (GI), glycemic load (GL), and carbohydrates have been shown to be associated with a variety of cancers, but their correlation with hepatocellular carcinoma (HCC) remains controversial. The purpose of our study was to investigate the correlation of GI, GL and carbohydrate with risk of HCC.Methods Systematic searches were conducted in PubMed, Embase and Web of Science until November 2020. According to the size of heterogeneity, the random effect model or the fixed effect model was performed to calculate the pooled relative risks (RRs) and 95% confidence intervals (CIs) for the correlation of GI, GL, and carbohydrates with the risk of HCC.Results Seven cohort studies involving 1,193,523 participants and 1,004 cases, and 3 case-control studies involving 827 cases and 5,502 controls were eventually included. The pooled results showed no significant correlation of GI (RR=1.11, 95%CI 0.80-1.53, I2= 62.2%), GL (RR=1.09, 95%CI 0.76-1.55, I2 = 66%), and carbohydrate (RR=1.09, 95%CI 0.84-1.32, I2=0%) with the risk of HCC in general population. Subgroup analysis revealed that in hepatitis B virus (HBV) or/and hepatitis C virus (HCV)-positive group, GI was not correlated with the risk of HCC (RR=0.65, 95%CI 0.32-1.32, p=0.475, I2=0.0%), while GL was significantly correlated with the risk of HCC (RR=1.52, 95%CI 1.04-2.23, p=0.016, I2=70.9%). In contrast, in HBV and HCV-negative group, both GI (RR=1.23, 95%CI 0.88-1.70, p=0.222, I2=33.6%) and GL (RR=1.17, 95% CI 0.83-1.64, p=0.648, I2=0%) were not correlated with the risk of HCC. Conclusion A high GL diet is correlated with a higher risk of HCC in people with hepatitis virus. A low GL diet may be recommended for patients with viral hepatitis to reduce the risk of HCC.


2020 ◽  
Vol 57 (1) ◽  
pp. 91-99
Author(s):  
Mansour MOGHIMI ◽  
Seyed Alireza DASTGHEIB ◽  
Naeimeh HEIRANIZADEH ◽  
Mohammad ZARE ◽  
Elnaz SHEIKHPOUR ◽  
...  

ABSTRACT BACKGROUND: The role of -251A>T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene in gastric cancer was intensively evaluated, but the results of these studies were inconsistent. OBJECTIVE: Therefore, we performed a meta-analysis to provide a comprehensive data on the association of IL-8 -251T>A polymorphism with gastric cancer. METHODS: All eligible studies were identified in PubMed, Web of Science, EMBASE, Wanfang and CNKI databases before September 01, 2019. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. RESULTS: A total of 33 case-control studies with 6,192 cases and 9,567 controls were selected. Overall, pooled data showed that IL-8 -251T>A polymorphism was significantly associated with an increased risk of gastric cancer under all five genetic models, i.e., allele (A vs T: OR=1.189, 95% CI 1.027-1.378, P=0.021), homozygote (AA vs TT: OR=1.307, 95% CI 1.111-1.536, P=0.001), heterozygote (AT vs TT: OR=1.188, 95% CI 1.061-1.330, P=0.003), dominant (AA+AT vs TT: OR=1.337, 95% CI 1.115-1.602, P=0.002) and recessive (AA vs AT+TT: OR=1.241, 95% CI 1.045-1.474, P=0.014). The stratified analysis by ethnicity revealed an increased risk of gastric cancer in Asians and mixed populations, but not in Caucasians. Moreover, stratified by country found a significant association in Chinese, Korean and Brazilian, but not among Japanese. CONCLUSION: This meta-analysis suggests that the IL-8 -251T>A polymorphism is associated with an increased risk of gastric cancer, especially by ethnicity (Asian and mixed populations) and country (Chinese, Korean and Brazilian).


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Marta Berta ◽  
Helena Lindgren ◽  
Kyllike Christensson ◽  
Sollomon Mekonnen ◽  
Mulat Adefris

Abstract Background It is believed that giving birth in an upright position is beneficial for both mother and the infant for several physiologic reasons. An upright positioning helps the uterus to contract more strongly and efficiently, the baby gets in a better position and thus can pass through the pelvis faster. Upright and lateral positions enables flexibility in the pelvis and facilitates the extension of the outlet. Before implementing a change in birthing positions in our clinics we need to review evidences available and context valid related to duration of second stage of labor and birthing positions. Therefore this review aimed to examine the effect of maternal flexible sacrum birth position on duration of second stage of labor. Method The research searched articles using bibliographical Databases: Medline/PUBMED, SCOPUS, Google scholar and Google. All study designs were considered while investigating the impact of maternal flexible sacrum birthing positioning in relation duration of second stage of labor. Studies including laboring mothers with normal labor and delivery. A total of 1985 women were included in the reviewed studies. We included both qualitative and quantitative analysis. Results We identified 1680 potential citations, of which 8 articles assessed the effect of maternal upright birth positioning on the reduction during the duration of second stage of labor. Two studies were excluded because of incomplete reports for meta analysis. The result suggested a reduction in duration of second stage of labor among women in a flexible sacrum birthing position, with a mean duration from 3.2–34.8. The pooled weighted mean difference with random effect model was 21.118(CI: 11.839–30.396) minutes, with the same significant heterogeneity between the studies (I2 = 96.8%, p < 000). Conclusion The second stage duration was reduced in cases of a flexible sacrum birthing position. Even though the reduction in duration varies across studies with considerable heterogeneity, laboring women should be encouraged to choose her comfortable birth position. Researchers who aim to compare different birthing positions should consider study designs which enable women to choose birthing position. Prospero registration number [CRD42019120618]


2006 ◽  
Vol 96 (07) ◽  
pp. 14-18 ◽  
Author(s):  
Jean-Francois Schved ◽  
Jean-Pierre Daures ◽  
Christine Biron-Andreani

SummaryThe magnitude of the association of factor V Leiden mutation with pregnancy-related venous thrombosis remains unclear. Our objective was to undertake a systematic review and a meta-analysis of the literature to estimate precisely the association of factor V Leiden mutation with the risk of first,or recurrent,pregnancy-related venous thromboembolism. Studies published before October 2005 were identified by Medline®. Using both fixed and random effect models, odds ratios (OR) with accompanying 95% confidential intervals (CI) were calculated for the factor V Leiden mutation and the clinical end-point (Yusuf-Peto adaptation of the Mantel-Haenszel, DerSimonian and Laird method).We identified 13 studies including 7 cohorts and 6 case control studies relating to factor V Leiden and pregnancy-related venous thrombosis.The results from the cohorts showe a pooled OR of 4.46 (95% CI,1.82–10.94;7,879 pooled women), with no evidence of statistical heterogeneity (p=0.36), for the risk of a first venous thromboembolism during pregnancy or the postpartum period associated with the factor V Leiden mutation.Case-control studies revealed a higher risk ( OR 8.6,95% CI, 5.85–12.63; 1,524 pooled women) with significant heterogeneity (p<0.005). Because of insufficient data, an analysis for the risk of recurrence could not be performed. Our findings emphasize the fact that limited data are available on this topic.This meta-analysis provides clinicians with an estimate of the average risk of a first thrombosis occurring during pregnancy in women carrying the factor V Leiden to assist the management of such women.


2015 ◽  
Vol 19 (8) ◽  
pp. 1457-1463 ◽  
Author(s):  
Yunping Zhou ◽  
Tao Wang ◽  
Shenyong Zhai ◽  
Wei Li ◽  
Qiang Meng

AbstractObjectivePrior studies on linoleic acid, the predominant n-6 fatty acid, and breast cancer risk have generated inconsistent results. We performed a meta-analysis to summarize the evidence regarding the relationship of dietary and serum linoleic acid with breast cancer risk.DesignPertinent studies were identified by a search of PubMed and EMBASE. The fixed- or random-effect pooled measure was selected based on between-study heterogeneity.ResultsEight prospective cohort studies and four prospective nested case–control studies, involving 10 410 breast cancer events from 358 955 adult females across different countries, were included in present study. Compared with the lowest level of linoleic acid, the pooled relative risk (RR; 95 % CI) of breast cancer was 0·98 (0·93, 1·04) for the highest level of linoleic acid. The pooled RR (95 % CI) for dietary and serum linoleic acid were 0·99 (0·92, 1·06) and 0·98 (0·88, 1·08), respectively. The RR (95 % CI) of breast cancer was 0·97 (0·91, 1·04), 0·95 (0·85, 1·07), 0·96 (0·86, 1·07), 0·98 (0·87, 1·10) and 0·99 (0·85, 1·14) for linoleic acid intake of 5, 10, 15, 20 and 25 g/d, respectively. The risk of breast cancer decreased by 1 % (RR=0·99; 95 % CI 0·93, 1·05) for every 10 g/d increment in linoleic acid intake.ConclusionsThis meta-analysis indicated that both dietary linoleic acid intake and serum linoleic acid level were associated with decreased risk of breast cancer, although none of the associations were statistically significant. Further investigations are warranted.


Pteridines ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 9-17
Author(s):  
Dexia Li ◽  
Enxia Wang ◽  
Xia Gao ◽  
Ping Li

AbstractObjective To investigate the correlation between the methylenetetrahydrofolate reductase (MTHFR) gene 677C> T polymorphism and fetal congenital defects.Method Original studies relevant to the MTHFR gene 677C>T single nucleotide polymorphism and fetal congenital defects were systematically searched in the electronic databases of Medline, EMBSE and China National Knowledge Infrastructure (CNKI). All relevant publications were screened for inclusion in the present work. The correlation between the MTHFR gene 677C > T single nucleotide polymorphism and the occurrence of fetal congenital defects was expressed as an odds ratio (OR) and its 95% confidence interval (95% CI). Publication bias was assessed by Begg’s funnel plot and Egger’s line regression test.Results Nineteen case-control studies were ultimately included in the present meta-analysis. The pooled results indicated that the general risk of fetal congenital defects was significantly elevated in subjects with the 677T allele of the MTHFR gene in dominant (OR=1.07,95%CI:1.03-1.12, P<0.05), homozygous (OR=1.17,95%CI:1.06-1.30, P<0.05) and recessive genetic models (OR=1.16,95%CI:1.03-1.31, P<0.05) through the random effect method. However, significant publication bias was identified upon pooling the individual data and evaluating the correlation.Conclusion According to the present evidence, the MTHFR gene 677C>T single nucleotide polymorphism is correlated with poor pregnancy outcomes, and subjects with the T allele have an increased risk of developing general fetal congenital defects.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Liyuan Han ◽  
Lina Zhang ◽  
Wenhua Xing ◽  
Renjie Zhuo ◽  
XiaLu Lin ◽  
...  

Aims. Published data on the associations of VEGF polymorphisms with diabetic retinopathy (DR) susceptibility are inconclusive. A systematic meta-analysis was undertaken to clarify this topic.Methods. Data were collected from the following electronic databases: PubMed, Embase, OVID, Web of Science, Elsevier Science Direct, Excerpta Medica Database (EMBASE), and Cochrane Library with the last report up to January 10, 2014. ORs and 95% CIs were calculated for VEGF–2578C/A (rs699947), –1154G/A (rs1570360), –460T/C (rs833061), −634G>C (rs2010963), and +936C/T (rs3025039) in at least two published studies. Meta-analysis was performed in a fixed/random effect model by using the software STATA 12.0.Results. A total of 11 studies fulfilling the inclusion criteria were included in this meta-analysis. A significant relationship between VEGF+936C/T (rs3025039) polymorphism and DR was found in a recessive model (OR = 3.19, 95% CI = 1.20–8.41, andP(z)=0.01) in Asian and overall populations, while a significant association was also found between –460T/C (rs833061) polymorphism and DR risk under a recessive model (OR = 2.12, 95% CI = 1.12–4.01, andP(z)=0.02).Conclusions. Our meta-analysis demonstrates that +936C/T (rs3025039) is likely to be associated with susceptibility to DR in Asian populations, and the recessive model of –460T/C (rs833061) is associated with elevated DR susceptibility.


2019 ◽  
Author(s):  
Marta Berta Badi ◽  
Helena Lindgren ◽  
Kyllike Christensson ◽  
Sollomon Mekonnen ◽  
Mulat Adefris

Abstract Background: it is believed that giving birth in an upright position is beneficial for both mother and the infant for several physiologic reasons. An upright positioning helps the uterus to contract more strongly and efficiently, the baby gets in a better position and thus can pass through the pelvis faster. Upright and lateral positions enables flexibility in the pelvis and facilitates the extension of the outlet. Before implementing a change in birthing positions in our clinics we need to review evidences available and context valid related to duration of second stage of labor and birthing positions. Objective: The aim of this review was to examine the effect of maternal flexible sacrum birth position on duration of second stage of labor. Method: The research searched articles using bibliographical Databases: Medline/PUBMED, SCOPUS, Google scholar and Google. All study designs were considered while investigating the impact of maternal flexible sacrum birthing positioning in relation duration of second stage of labor. Studies including laboring mothers with normal labor and delivery. A total of 1,985 women were included in the reviewed studies. We included both qualitative and quantitative analysis. Results: We identified 1,680 potential citations, of which 8 articles assessed the effect of maternal upright birth positioning on the reduction during the duration of second stage of labor. Two studies were excluded because of incomplete reports for meta analysis. The result suggested a reduction in duration of second stage of labor among women in a flexible sacrum birthing position, with a mean duration from 3.2-34.8. The pooled weighted mean difference with random effect model was 21.118(CI: 11.839-30.396) minutes, with the same significant heterogeneity between the studies (I2=96.8%, p<000). Conclusion: The second stage duration was reduced in cases of a flexible sacrum birthing position. Even though the reduction in duration varies across studies with considerable heterogeneity, laboring women should be encouraged to choose her comfortable birth position. Researchers who aim to compare different birthing positions should consider study designs which enable women to choose birthing position. Prospero registration number [CRD42019120618]


2020 ◽  
Author(s):  
Tesfaye Getachew Charkos ◽  
Yawen Liu ◽  
Kemal Sherefa Oumer ◽  
Ann M Vuong ◽  
Shuman Yang

Abstract Introduction The association between β-carotene intake and risk of fracture has been reported inconsistently. We conducted a meta-analysis to investigate the association between β-carotene intake and risk of fracture using a Bayesian approach. Methods We systematically searched PubMed, EMBASE and Cochrane library database for relevant articles until December 2019. We also performed a hand search based on reference lists from published articles. The Bayesian random effect model was used to synthesize data from individual studies. Results Nine studies with a total of 190,545 men and women were included in this meta-analysis. The participants' average age was 59.8 years old. For β-carotene intake, the pooled RR of any fracture was 0.67 (95% Credible Interval (CrI): 0.51-0.82; heterogeneity: P = 0.66, I 2 =0.00%) and 0.63 (95%CrI: 0.44-0. 82) for hip fracture. By study design, the pooled RRs were 0.55 (95% CrI: 0.14-0.96) for case-control studies and 0.82 (95% CrI: 0.58-0.99) for cohort studies. By geographic region, the pooled RRs were 0.58 (95% CrI: 0.28-0.89) for studies conducted in China, 0.86 (95% CrI: 0.35-0.1.37) in America and 0.91(95% CrI: 0.75-1.00) Europe. By gender: the pooled RRs were 0.88 (95% CrI: 0.73-0.99) for males and 0.76 (95% CrI: 0.44-1.07) for females. The probability that β-carotene intakes reduce the risk of any fracture and hip fracture by more than 20% was 95%. Conclusion The present meta-analysis suggests that β-carotene intake was inversely associated with fracture risk, consistently observed for case-control and cohort studies. Further randomized control trial is warranted to confirm this finding.


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