Global diversity of policy, coverage, and demand of COVID-19 vaccines: a descriptive study

BackgroundHundreds of millions of doses of COVID-19 vaccines have been administered globally, but progress in vaccination varies considerably between countries. We aim to provide an overall picture of COVID-19 vaccination campaigns, including policy, coverage, and demand of COVID-19 vaccines. MethodsWe conducted a descriptive study of vaccination policy and doses administered data obtained from multiple public sources as of 23 October 2021. We used these data to develop coverage indicators and explore associations of vaccine coverage with socioeconomic and healthcare-related factors. We estimated vaccine demand as numbers of doses required to complete vaccination of countries target populations according to their national immunization program policies. FindingsUse of both mRNA and adenovirus vectored vaccines was the most commonly used COVID-19 vaccines formulary in high-income countries, while adenovirus vectored vaccines were the most widely used vaccines worldwide (176 countries). Almost all countries (98.3%, 173/176) have authorized vaccines for the general public, with 53.4% (94/176) targeting individuals over 12 years and 33.0% (58/176) targeting those [≥]18 years. Forty-one and sixty-seven countries have started additional-dose and booster-dose vaccination programs, respectively. Globally, there have been 116.5 doses administered per 100 target population, although with marked inter-region and inter-country heterogeneity. Completed vaccination series coverage ranged from 0% to more than 95.0% of country target populations, and numbers of doses administered ranged from 0 to 239.6 per 100 target population. Doses administered per 100 total population correlated with healthcare access and quality index (R2 = 0.58), socio-demographic index (R2 = 0.56), and GDP per capita (R2 = 0.65). At least 5.54 billion doses will be required to complete interim vaccination programs - 4.65 billion for primary immunization and 0.89 billion for additional/booster programs. Globally, 0.84 and 0.96 dose per individual in the target population are needed for primary immunization and additional/booster programs, respectively. InterpretationThere is wide country-level disparity and inequity in COVID-19 vaccines rollout, suggesting large gaps in immunity, especially in low-income countries. FundingKey Program of the National Natural Science Foundation of China, the US National Institutes of Health. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSWe searched PubMed for articles in any language published up to October 21, 2021, using the following search terms: ("COVID-19" OR "SARS-CoV-2") AND ("vaccination" OR "vaccine") AND ("inequalit*" OR "inequity" OR "disparit*" OR "heterogeneity"). We also searched for dashboards associated with vaccine rollout from public websites. We identified several studies on tracking global inequalities of vaccine access, one of which constructed a COVID-19 vaccine dashboard (Our World in Data), and another that explored disparities in COVID-19 vaccination among different-income countries. However, we found no studies that depict global COVID-19 vaccination policies country-by-country and estimate demand for vaccine necessary to completely vaccinate countries designated target populations. Added value of this studyTo our knowledge, our study provides the most recent picture of COVID-19 vaccination campaigns, focusing on global vaccination policy and target-population demand. We found a diverse portfolio of vaccines in five technical platforms being administered globally, with 173 countries having authorized administration of vaccines to the general public in various age groups. We observed inter-region and inter-country heterogeneity in one-or-more-dose and full-dose coverage; countries with higher socio-demographic or health resource-related levels had higher coverage. We estimated dose-level demand for completing primary immunization programs and additional/booster dose programs separately. Implications of all the available evidenceWorldwide disparity and inequity of vaccine rollout implies that susceptibility among unvaccinated populations in some countries may impede or reverse pandemic control, especially in face of the emergence of variants and the dilemma of waning antibodies. Our findings suggest that global-level responses to the pandemic - financially, politically, and technically - are needed to overcome complex challenges that lie ahead.

Effects and mechanism of combined exposure of di(2-ethylhexyl) phthalate and bisphenol A on glucose metabolism in female rats during gestational and lactational period / 中国职业医学

OBJECTIVE: To investigate the effects of combined exposure to di(2-ethylhexyl) phthalate(DEHP) and bisphenol A(BPA) on glucose metabolism in female rats during gestational and lactation periods, and its possible mechanism. METHODS: Twenty-four specific pathogen free pregnant SD rats were randomly divided into control group, DEHP group, BPA group, and combined exposure group, with 6 rats in each group. From the 5 th day of gestation to the 21 st day after birth of the offspring, the rats in the DEHP group were treated with DEHP 600 mg/kg body weight(bw); rats in BPA group were treated with 80 mg/kg bw BPA, and rats in combined exposure group were treated with 600 mg/kg bw DEHP and 80 mg/kg bw BPA by intragastric perfusion, while the rats in the control group were given the same amount of corn oil, once per day. After exposure, maternal rats were sacrificed immediately. The levels of glucose metabolism related indicators in liver tissues and serum were examined, and the mRNA and protein expression of phosphatidylinositol 3-kinase(PI3 K)/protein kinase B(AKT) signaling pathway related factors in liver tissues were detected by real-time fluorescence quantitative polymerase chain reaction and Western blot. RESULTS: Except for the activity of phosphoenolpyruvate carboxykinase(PEPCK) in BPA group, the levels of liver glycogen and serum high density lipoprotein cholesterol(HDL-C) in rats of the 3 exposure groups decreased(P<0.05), while the activity of serum PEPCK and the level of low density lipoprotein cholesterol(LDL-C) increased(P<0.05) compared with rats in the control group. The levels of liver glycogen and serum HDL-C in the combined exposure group were lower than that in the BPA group(P<0.05), while the level of serum LDL-C were lower than that in DEHP group and BPA group(P<0.05). The levels of serum glycosylated serum protein, total cholesterol and triglyceride in the 4 groups were not statistically different when compared with each other(P>0.05). Except for the PI3 K protein in DEHP group, the mRNA and protein expression of PI3 K, AKT, and glucose transporter 4 in liver tissues of rats in the 3 exposure groups decreased(P<0.05), and the mRNA expression of forkhead box protein 1(Foxo1) decreased(P<0.05), but the protein expression of FOXO1 increased(P<0.05) compared with the control group. CONCLUSION: Exposure to DEHP or BPA during pregnancy and lactation can cause glucose metabolism disorders in rats. The combined exposure of DEHP and BPA has certain synergistic effect. This process may be achieved through the PI3 K/AKT signaling pathway.

Constructing the dual luciferase reporter vector containing human DRD1 promoter region / 中国组织工程研究

BACKGROUND:The polymorphisms of dopamine receptor in promoter region wil affect the expression of the receptor, thereby affecting the dopaminergic neurotransmitter, final y lead to related diseases. OBJECTIVE:To construct the dual luciferase reporter vector containing human DRD1 promoter region and determine its activity, which could provide the basic tool for studying the transcriptional regulation of DRD1 gene. METHODS:DRD1 promoter sequence was amplified by PCR using the human blood genomic DNA and cloned into pGM-T vector. After sequencing, the correctly constructed vectors were ligated to the firefly luciferase reporter plasmid pGL3-Basic. The cloned pGL3-Basic vectors were transfected into HEK293 using cationic liposome method. In the meanwhile, PGL3-Basic vector with no promoter was co-transfected with pGL3-TK plasmid as negative control group. The relative fluorescence intensity was measured by chemiluminescence. RESULTS AND CONCLUSION:(1) Recombinant luciferase reporter gene vectors were confirmed by restriction analysis and sequencing. (2) Compared with the negative control group, the HEK293 cel s transfected by recombinant vectors presented transcriptional activity. (3) In conclusion, luciferase reporter gene vectors containing DRD1 promoter region are successful y constructed and can provide the basic tool for further study on the transcriptional regulation of DRD1.