Safety and Immunogenicity of a ChAd155-Vectored Respiratory Syncytial Virus Vaccine in Infants 6-7 Months of age: A Phase 1/2 Randomized Trial

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections in infants. This phase 1/2, observer-blind, randomized, controlled study assessed the safety and immunogenicity of an investigational chimpanzee-derived adenoviral vector RSV vaccine (ChAd155-RSV, expressing RSV F, N, and M2-1) in infants.

METHODS

Healthy 6- to 7-month-olds were 1:1:1-randomized to receive 1 low ChAd155-RSV dose (1.5 × 1010 viral particles) followed by placebo (RSV_1D); 2 high ChAd155-RSV doses (5 × 1010 viral particles) (RSV_2D); or active comparator vaccines/placebo (comparator) on days 1 and 31. Follow-up lasted approximately 2 years.

RESULTS

Two hundred one infants were vaccinated (RSV_1D: 65; RSV_2D: 71; comparator: 65); 159 were RSV-seronaive at baseline. Most solicited and unsolicited adverse events after ChAd155-RSV occurred at similar or lower rates than after active comparators. In infants who developed RSV infection, there was no evidence of vaccine-associated enhanced respiratory disease (VAERD). RSV-A neutralizing titers and RSV F-binding antibody concentrations were higher post-ChAd155-RSV than postcomparator at days 31, 61, and end of RSV season 1 (mean follow-up, 7 months). High-dose ChAd155-RSV induced stronger responses than low-dose, with further increases post-dose 2.

CONCLUSIONS

ChAd155-RSV administered to 6- to 7-month-olds had a reactogenicity/safety profile like other childhood vaccines, showed no evidence of VAERD, and induced a humoral immune response. Clinical Trials Registration. NCT03636906.

Safety and Immunogenicity of a ChAd155-Vectored Respiratory Syncytial Virus (RSV) Vaccine in Healthy RSV-Seropositive Children 12-23 Months of Age

BACKGROUND

Safe and effective respiratory syncytial virus (RSV) vaccines remain elusive. This was a phase I/II trial (NCT02927873) of ChAd155-RSV, an investigational chimpanzee adenovirus-RSV vaccine expressing 3 proteins (fusion, nucleoprotein, and M2-1), administered to 12-23-month-old RSV-seropositive children followed up for 2 years after vaccination.

METHODS

Children were randomized to receive 2 doses of ChAd155-RSV or placebo (at a 1:1 ratio) (days 1 and 31). Doses escalated from 0.5 × 1010 (low dose [LD]) to 1.5 × 1010 (medium dose [MD]) to 5 × 1010 (high dose [HD]) viral particles after safety assessment. Study end points included anti-RSV-A neutralizing antibody (Nab) titers through year 1 and safety through year 2.

RESULTS

Eighty-two participants were vaccinated, including 11, 14, and 18 in the RSV-LD, RSV-MD, and RSV-HD groups, respectively, and 39 in the placebo groups. Solicited adverse events were similar across groups, except for fever (more frequent with RSV-HD). Most fevers were mild (≤38.5°C). No vaccine-related serious adverse events or RSV-related hospitalizations were reported. There was a dose-dependent increase in RSV-A Nab titers in all groups after dose 1, without further increase after dose 2. RSV-A Nab titers remained higher than prevaccination levels at year 1.

CONCLUSIONS

Three ChAd155-RSV dosages were found to be well tolerated. A dose-dependent immune response was observed after dose 1, with no observed booster effect after dose 2. Further investigation of ChAd155-RSV in RSV-seronegative children is warranted.

CLINICAL TRIALS REGISTRATION

NCT02927873.

Cost of Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infection Management in Young Children at the Regional and Global Level: A Systematic Review and Meta-Analysis

Background

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection (ALRI) in young children aged <5 years.

Methods

We aimed to identify the global inpatient and outpatient cost of management of RSV-ALRI in young children to assist health policy makers in making decisions related to resource allocation for interventions to reduce severe morbidity and mortality from RSV in this age group. We searched 3 electronic databases including Global Health, Medline, and EMBASE for studies reporting cost data on RSV management in children under 60 months from 2000 to 2017. Unpublished data on the management cost of RSV episodes were collected through collaboration with an international working group (RSV GEN) and claim databases.

Results

We identified 41 studies reporting data from year 1987 to 2017, mainly from Europe, North America, and Australia, covering the management of a total of 365 828 RSV disease episodes. The average cost per episode was €3452 (95% confidence interval [CI], 3265–3639) and €299 (95% CI, 295–303) for inpatient and outpatient management without follow-up, and it increased to €8591(95% CI, 8489–8692) and €2191 (95% CI, 2190–2192), respectively, with follow-up to 2 years after the initial event.

Conclusions

Known risk factors (early and late preterm birth, congenital heart disease, chronic lung disease, intensive care unit admission, and ventilator use) were associated with €4160 (95% CI, 3237–5082) increased cost of hospitalization. The global cost of inpatient and outpatient RSV ALRI management in young children in 2017 was estimated to be approximately €4.82 billion (95% CI, 3.47–7.93), 65% of these in developing countries and 55% of global costs accounted for by hospitalization. We have demonstrated that RSV imposed a substantial economic burden on health systems, governments, and the society.

Depressive disorders and anti-parkinson drug treatment: a case register study

OBJECTIVE

To estimate the rate of treatment with anti-parkinson drugs (APD) among patients with depression.

METHOD

In a nationwide case register linkage study, all persons with a main diagnosis of depression during 5 years were identified. A control group of persons with diagnoses of osteoarthritis was included. The subsequent risk of getting treatment with APD was estimated for the two groups. Statistical analyses involved Poisson's regression and competing risk models.

RESULTS

A total of 14 991 persons were included. The rate of getting APD was 2.57 (95% CI: 1.46-4.52) times higher for persons with depression than for persons with osteoarthritis. Overall, the rate was highest for men. However, women with depression had a 3.89 (95% CI: 1.98-7.62) times higher rate of APD treatment as women with osteoarthritis while no significant difference was found among men.

CONCLUSION

Provided that prescription of APD reflects the presence of Parkinson's disease, results support a positive statistical association between depressive disorders and Parkinson's disease.

Temporal changes in suicide rates for persons treated and not treated with antidepressants in Denmark during 1995-1999

OBJECTIVE

To compare the temporal changes in suicide rate among patients treated with antidepressants with the change in suicide rate among persons who have not been treated with antidepressants during 1995-1999.

METHOD

In a historic prospective national pharmacoepidemiological register linkage study by using four Danish registers we included 438,625 patients who had purchased antidepressants, and compared them with 1,199,057 population based control persons. The annual rate of suicide was estimated using Poisson regression analyses.

RESULTS

The suicide rate decreased for persons treated with antidepressants as well as for persons not treated with antidepressants. The proportion of persons, who committed suicide and who had not been treated with antidepressants decreased. The reduction in suicide rate was more pronounced among persons treated with SSRIs or older antidepressants than among persons not treated with antidepressants.

CONCLUSION

Several factors contribute to the decreasing suicide rate. The most pronounced decrease in suicide rate was found among persons treated with antidepressants.

Evaluation of PCR-restriction profile analysis and IS2404 restriction fragment length polymorphism and amplified fragment length polymorphism fingerprinting for identification and typing of Mycobacterium ulcerans and M. marinum

Mycobacterium ulcerans and M. marinum are emerging necrotizing mycobacterial pathogens that reside in common reservoirs of infection and exhibit striking pathophysiological similarities. Furthermore, the interspecific taxonomic relationship between the two species is not clear as a result of the very high phylogenetic relatedness (i.e., >99.8% 16S rRNA sequence similarity), in contrast to only 25 to 47% DNA relatedness. To help understand the genotypic affiliation between these two closely related species, we performed a comparative analysis including PCR restriction profile analysis (PRPA), IS2404 restriction fragment length polymorphism (RFLP), and amplified fragment length polymorphism (AFLP) on a set of M. ulcerans (n = 29) and M. marinum (n = 28) strains recovered from different geographic origins. PRPA was based on a triple restriction of the 3' end region of 16S rRNA, which differentiated M. ulcerans into three types; however, the technique could not distinguish M. marinum from M. ulcerans isolates originating from South America and Southeast Asia. RFLP based on IS2404 produced six M. ulcerans types related to six geographic regions and did not produce any band with M. marinum, confirming the previous findings of Chemlal et al. (K. Chemlal, K. DeRidder, P. A. Fonteyne, W. M. Meyers, J. Swings, and F. Portaels, Am. J. Trop. Med. Hyg. 64:270-273, 2001). AFLP analysis resulted in profiles which grouped M. ulcerans and M. marinum into two separate clusters. The numerical analysis also revealed subgroups among the M. marinum and M. ulcerans isolates. In conclusion, PRPA appears to provide a rapid method for differentiating the African M. ulcerans type from other geographical types but is unsuitable for interspecific differentiation of M. marinum and M. ulcerans. In comparison, whole- genome techniques such as IS 2404-RFLP and AFLP appear to be far more useful in discriminating between M. marinum and M. ulcerans, and may thus be promising molecular tools for the differential diagnosis of infections caused by these two species.

Subwavelength surface-relief gratings fabricated by microcontact printing of self-assembled monolayers

We have designed and tested subwavelength diffractive optical elements consisting of surface-relief gratings made by microcontact printing of self-assembled monolayers. The first device is a beam deflector for 1.55-mum operation consisting of a surface-relief grating made up of eight pillars over one period (9.3 mum) of the grating. The widths of the pillars vary to approximate a linear phase profile within each grating period. The second device is a quarter-wave plate for 632.8-nm operation consisting of a subwavelength surface-relief grating with a 300-nm period and 58% duty cycle.

The production of nitric oxide and tumor necrosis factor by murine macrophages infected with mycobacterial strains differing by hemolytic activity

In this study, we compared the secretion of nitric oxide (NO) and tumor necrosis factor (TNF-alpha) by murine macrophages infected in vitro with hemolytic or unhemolytic mycobacteria isolates. We observed that unhemolytic mycobacteria induced more intensive NO production by macrophages and were more susceptible to bactericidal effect of mononuclear phagocytes than hemolytic mycobacterial strains. In contrast, the high-virulence hemolytic isolates induced significantly stronger TNF-alpha production by infected macrophages than the low-virulence unhemolytic bacilli.

Wave-plate polarizing beam splitter based on a form-birefringent multilayer grating

We have fabricated a novel device that acts as a quarter-wave plate at normal incidence and as a polarizing beam splitter at an angle of incidence of ~40 deg . The device is made from a multilayer (SiO(2) /Si(3)N(4)) surface-relief zeroth-order one-dimensional grating with a period of 0.3 mum . The device is designed for an operating wavelength of 632.8 nm. We designed the device by using rigorous coupled-wave analysis and fabricated it by direct-write electron-beam lithography and reactive ion etching. Measurements confirmed the performance of the device as a wave plate and as a polarizing beam splitter.

Acute effect of cigarette smoking on the coronary circulation: constriction of epicardial and resistance vessels

OBJECTIVES

This study was performed to determine the acute effect of cigarette smoking on proximal and distal epicardial conduit and coronary resistance vessels.

BACKGROUND

Cigarette smoking causes constriction of epicardial arteries and a decrease in coronary blood flow in patients with coronary artery disease, despite an increase in myocardial oxygen demand. The role of changes in resistance vessel tone in the acute coronary hemodynamic effect of smoking has not been examined.

METHODS

Twenty-four long-term smokers were studied during cardiac catheterization after vasoactive medications had been discontinued. The effect of smoking one cigarette 10 to 15 mm long on proximal and distal conduit vessel segments was assessed before and immediately after smoking and at 5, 15 and 30 min after smoking (n = 8). To determine the effect of smoking on resistance vessels, coronary flow velocity was measured in a nonobstructed artery with a 3F intracoronary Doppler catheter before and for 5 min after smoking (n = 8). Eight patients were studied without smoking to control for spontaneous changes in conduit arterial diameter (n = 5) and resistance vessel tone (n = 3).

RESULTS

The average diameter of proximal coronary artery segments decreased from 2.56 +/- 0.12 mm (mean +/- SEM) before smoking to 2.41 +/- 0.09 mm 5 min after smoking (-5 +/- 2%, p < 0.05). Distal coronary diameter decreased from 1.51 +/- 0.07 to 1.39 +/- 0.06 mm (-8 +/- 2%, p < 0.01). Marked focal vasoconstriction after smoking was observed in two patients. Coronary diameter returned to baseline by 30 min after smoking. There was no change in vessel diameter in control patients. Despite a significant increase in the heart rate-mean arterial pressure product, coronary flow velocity decreased by 7 +/- 4% (p < 0.05) and coronary vascular resistance increased by 21 +/- 4% (p < 0.01) 5 min after smoking. There was no change in these variables in the control subjects.

CONCLUSIONS

Smoking causes immediate constriction of proximal and distal epicardial coronary arteries and an increase in coronary resistance vessel tone, despite an increase in myocardial oxygen demand. These acute coronary hemodynamic effects may contribute to the adverse cardiovascular consequences of cigarette smoking.

Comparison of coronary vasodilation with intravenous dipyridamole and adenosine

Although both intravenous dipyridamole and adenosine have been used to produce coronary vasodilation during cardiac imaging, the relative potency of the commonly administered doses of these agents has not been evaluated. Accordingly, the coronary and systemic hemodynamic effects of intravenous adenosine (140 micrograms/kg per min) and intravenous dipyridamole (0.56 mg/kg over 4 min) were compared with a maximally dilating dose of intracoronary papaverine in 15 patients. Coronary blood flow responses were assessed using a Doppler catheter in a nonstenotic coronary artery. The protocol was discontinued in two patients because of transient asymptomatic atrioventricular (AV) block during adenosine infusion. The mean heart rate increased more with adenosine (11 +/- 9 beats/min) and dipyridamole (11 +/- 7 beats/min) than with papaverine (4 +/- 3 beats/min, p less than 0.05 vs. adenosine and papaverine). The mean arterial pressure decreased less with dipyridamole (-10 +/- 3 mm Hg) and papaverine (-9 +/- 4 mm Hg) than with adenosine (-16 +/- 5 mm Hg, p less than 0.01 vs. dipyridamole and papaverine). The peak/rest coronary blood flow velocity ratio was greater with papaverine (3.9 +/- 1.1) than with adenosine (3.4 +/- 1.2, p less than or equal to 0.05 vs. papaverine) or dipyridamole (3.1 +/- 1.2, p less than 0.01 vs. papaverine). A larger decrease in coronary resistance as measured by the coronary vascular resistance index occurred with papaverine (0.25 +/- 0.06) and adenosine (0.26 +/- 0.09) than with dipyridamole (0.31 +/- 0.10, p less than 0.01 vs. papaverine, p less than 0.05 vs. adenosine).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of atherosclerosis on cerebral vascular responses to activation of leukocytes and platelets in monkeys

The goal of this study was to test the hypothesis that atherosclerosis alters responses of cerebral arteries and the ocular circulation to the activation in vivo of leukocytes and platelets. We measured blood flow to the brain and eye using microspheres and pressure in the cerebral microvessels of normal and atherosclerotic monkeys. The intracarotid injection of 10(-7) M N-formyl-L-methionyl-L-leucyl-L-phenylalanine to activate leukocytes did not alter cerebral blood flow in 11 normal or 10 atherosclerotic monkeys but increased the resistance of large cerebral arteries by 46 +/- 11% (mean +/- SEM) in the atherosclerotic animals. The injection of N-formyl-L-methionyl-L-leucyl-L-phenylalanine did not alter blood flow to the eye in 10 normal monkeys but decreased blood flow to the choroid by 38 +/- 9% in 11 atherosclerotic monkeys. The intracarotid injection of 3 x 10(-9) M prostaglandin E2, a leukocyte product, produced an increase in the resistance of large cerebral arteries in five atherosclerotic but not in six normal monkeys. Prostaglandin E2 reduced blood flow to the retina and choroid in the atherosclerotic monkeys by 62 +/- 22% and 65 +/- 17%, respectively. The intracarotid infusion of 25 micrograms/min collagen to activate platelets increased cerebral blood flow by 21 +/- 5% in 10 normal monkeys but did not alter it in 11 atherosclerotic monkeys. Collagen did not alter blood flow to the choroid in 10 normal monkeys but decreased it by 29 +/- 8% in 11 atherosclerotic monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)