腺病毒对人体健康的影响

BACKGROUND Respiratory syncytial virus (RSV) infection causes considerable illness in older adults. The efficacy and safety of an investigational bivalent RSV prefusion F protein-based (RSVpreF) vaccine in this population are unknown. METHODS In this ongoing, phase 3 trial, we randomly assigned, in a 1:1 ratio, adults (≥60 years of age) to receive a single intramuscular injection of RSVpreF vaccine at a dose of 120 μg (RSV subgroups A and B, 60 μg each) or placebo. The two primary end points were vaccine efficacy against seasonal RSV-associated lower respiratory tract illness with at least two or at least three signs or symptoms. The secondary end point was vaccine efficacy against RSV-associated acute respiratory illness. RESULTS At the interim analysis (data-cutoff date, July 14, 2022), 34,284 participants had received RSVpreF vaccine (17,215 participants) or placebo (17,069 participants). RSV-associated lower respiratory tract illness with at least two signs or symptoms occurred in 11 participants in the vaccine group (1.19 cases per 1000 person-years of observation) and 33 participants in the placebo group (3.58 cases per 1000 person-years of observation) (vaccine efficacy, 66.7%; 96.66% confidence interval [CI], 28.8 to 85.8); 2 cases (0.22 cases per 1000 person-years of observation) and 14 cases (1.52 cases per 1000 person-years of observation), respectively, occurred with at least three signs or symptoms (vaccine efficacy, 85.7%; 96.66% CI, 32.0 to 98.7). RSV-associated acute respiratory illness occurred in 22 participants in the vaccine group (2.38 cases per 1000 person-years of observation) and 58 participants in the placebo group (6.30 cases per 1000 person-years of observation) (vaccine efficacy, 62.1%; 95% CI, 37.1 to 77.9). The incidence of local reactions was higher with vaccine (12%) than with placebo (7%); the incidences of systemic events were similar (27% and 26%, respectively). Similar rates of adverse events through 1 month after injection were reported (vaccine, 9.0%; placebo, 8.5%), with 1.4% and 1.0%, respectively, considered by the investigators to be injection-related. Severe or life-threatening adverse events were reported in 0.5% of vaccine recipients and 0.4% of placebo recipients. Serious adverse events were reported in 2.3% of participants in each group through the data-cutoff date. CONCLUSIONS RSVpreF vaccine prevented RSV-associated lower respiratory tract illness and RSV-associated acute respiratory illness in adults (≥60 years of age), without evident safety concerns. (Funded by Pfizer; RENOIR ClinicalTrials.gov number, NCT05035212; EudraCT number, 2021-003693-31.).

为测定我国朱临床症状、乳鼠神经毒力不同的登革２型病毒流体株５′和３′端非编码区序列（untranslated region,UTR)，分析二级结构差异与毒力变化的关系，分别从Ｄ２－０４、Ｄ２－４４株感染的Ｃ６／３６细胞及鼠脑中提取总ＲＮＡ，以该ＲＮＡ ，利用ＲＡＣＥ法，分别扩增了Ｄ２－０４、Ｄ２－４４株的５′和３′末端cDNA片段，将其分别为pGEM-T载体连接得到重组质粒，测定上述cDNA插入片段的序列。用ＲＮＡdraw软件预测Ｄ２－０４Ｄ２－４４株５′和３′端编码区的二级结构。Ｄ２－０４、Ｄ２－４４株５′端和３′非编码区分别有９６和４５４个核苷酸，其中５′非编码区５９位Ｃ（Ｄ２－０４）→Ｔ（Ｄ２－４４，使Ｄ２－４４二级结构稳定性下降；３′端非编码区有１５个核苷酸不同，其中Ｔ（３５５）→Ａ，Ｔ（３２６）→Ｇ引起了所在位置二级结构自由能变化，且分别位于两上保守序列区（conserved sequence,CS)ＣＳ１、ＣＳ２Ａ这些位点变化可能与毒力有关。

登革病毒(Dengue virus,DENV)是一种通过伊蚊传播的单股正链RNA病毒,属于黄病毒科(Flaviviridae)黄病毒属(Flavivirus).DENV有4种血清型:DENV1、DENV2、DENV3和DENV4,无论感染了哪一型,出现的症状多为发热、头痛、关节疼痛等,大多数人初次感染会自然痊愈,但若再次受到不同型DENV的感染,很容易引发严重的登革出血热(dengue hemorrhagic fever,DHF)或是登革休克综合征(dengue shock syndrome,DSS)[1]。