Safety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants

We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection. A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated. No vaccine-associated serious adverse events were recorded. The full- and half-dose BNT162b2 boosted anti-SARS-CoV-2 binding antibody levels (3.9- and 4.5-fold, respectively) and neutralizing antibody levels (4.4- and 10-fold). Binding and neutralizing antibodies following half-dose Ad26.COV2.S were not significantly boosted. Full-dose Ad26.COV2.S did not boost binding antibodies but slightly enhanced neutralizing antibodies (2.1-fold). ADCC was marginally increased only after a full-dose BNT162b2. T-cell responses followed a similar pattern to neutralizing antibodies. Six months post-boost, antibody and T-cell responses had waned to baseline levels. While we detected strong anti-vector immunity, there was no correlation between anti-vector immunity in Ad26.COV2.S recipients and spike-specific neutralizing antibody or T-cell responses post-Ad26.COV2.S boosting. Overall, in the context of hybrid immunity, boosting with heterologous full- or half-dose BNT162b2 mRNA vaccine demonstrated superior immunogenicity 2 weeks post-vaccination compared to homologous Ad26.COV2.S, though rapid waning occurred by 12 weeks post-boost. Trial Registration: The study has been registered to the South African National Clinical Trial Registry (SANCTR): DOH-27-012022-7841. The approval letter from SANCTR has been provided in the up-loaded documents.

Safety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants

Background

We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection.

Methods

A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated.

Results

No vaccine-associated serious adverse events were recorded. The full- and half-dose BNT162b2 boosted anti-SARS-CoV-2 binding antibody levels (3.9- and 4.5-fold, respectively) and neutralizing antibody levels (4.4- and 10-fold). Binding and neutralizing antibodies following half-dose Ad26.COV2.S were not significantly boosted. Full-dose Ad26.COV2.S did not boost binding antibodies but slightly enhanced neutralizing antibodies (2.1-fold). ADCC was marginally increased only after a full-dose BNT162b2. T-cell responses followed a similar pattern to neutralizing antibodies. Six months post-boost, antibody and T-cell responses had waned to baseline levels. While we detected strong anti-vector immunity, there was no correlation between anti-vector immunity in Ad26.COV2.S recipients and spike-specific neutralizing antibody or T-cell responses post-Ad26.COV2.S boosting.

Conclusion

In the context of hybrid immunity, boosting with heterologous full- or half-dose BNT162b2 mRNA vaccine demonstrated superior immunogenicity 2 weeks post-vaccination compared to homologous Ad26.COV2.S, though rapid waning occurred by 12 weeks post-boost.

Trial Registration

South African National Clinical Trial Registry (SANCR): DOH-27-012022-7841.

Funding

South African Medical Research Council (SAMRC) and South African Department of Health (SA DoH).

Novavax NVX-COV2373 triggers neutralization of Omicron sub-lineages

The SARS-CoV-2 Omicron (B.1.1.529) Variant of Concern (VOC) and its sub-lineages (including BA.2, BA.4, BA.5, BA.2.12.1) contain spike mutations that confer high level resistance to neutralizing antibodies induced by vaccination with ancestral spike or infection with previously circulating variants. The NVX-CoV2373 vaccine, a protein nanoparticle vaccine containing the ancestral spike sequence, has value in countries with constrained cold-chain requirements. Here we report neutralizing titers following two or three doses of NVX-CoV2373. We show that after two doses, Omicron sub-lineages BA.1 and BA.4/BA.5 were resistant to neutralization by 72% (21/29) and 59% (17/29) of samples respectively. However, after a third dose of NVX-CoV2373, we observed high titers against Omicron BA.1 (GMT: 1,197) and BA.4/BA.5 (GMT: 582), with responses similar in magnitude to those triggered by three doses of an mRNA vaccine. These data are of particular relevance as BA.4/BA.5 is dominating in multiple locations, and highlight the potential utility of the NVX-CoV2373 vaccine as a booster in resource-limited environments.

My Baby's Movements: a stepped-wedge cluster-randomised controlled trial of a fetal movement awareness intervention to reduce stillbirths

OBJECTIVE

The My Baby's Movements (MBM) trial aimed to evaluate the impact on stillbirth rates of a multifaceted awareness package (the MBM intervention).

DESIGN

Stepped-wedge cluster-randomised controlled trial.

SETTING

Twenty-seven maternity hospitals in Australia and New Zealand.

POPULATION

Women with a singleton pregnancy without major fetal anomaly at ≥28 weeks of gestation from August 2016 to May 2019.

METHODS

The MBM intervention was implemented at randomly assigned time points, with the sequential introduction of eight groups of between three and five hospitals at 4-monthly intervals. Using generalised linear mixed models, the stillbirth rate was compared in the control and the intervention periods, adjusting for calendar time, study population characteristics and hospital effects.

MAIN OUTCOME MEASURES

Stillbirth at ≥28 weeks of gestation.

RESULTS

There were 304 850 births with 290 105 births meeting the inclusion criteria: 150 053 in the control and 140 052 in the intervention periods. The stillbirth rate was lower (although not statistically significantly so) during the intervention compared with the control period (2.2/1000 versus 2.4/1000 births; aOR 1.18, 95% CI 0.93-1.50; P = 0.18). The decrease in stillbirth rate was greater across calendar time: 2.7/1000 in the first versus 2.0/1000 in the last 18 months. No increase in secondary outcomes, including obstetric intervention or adverse neonatal outcome, was evident.

CONCLUSIONS

The MBM intervention did not reduce stillbirths beyond the downward trend over time. As a result of low uptake, the role of the intervention remains unclear, although the downward trend across time suggests some benefit in lowering the stillbirth rate. In this study setting, an awareness of the importance of fetal movements may have reached pregnant women and clinicians prior to the implementation of the intervention.

TWEETABLE ABSTRACT

The My Baby's Movements intervention to raise awareness of decreased fetal movement did not significantly reduce stillbirth rates.

A core outcome set for the treatment of pregnant women with pregestational diabetes: an international consensus study

Objective

To develop a core outcome set (COS) for randomised controlled trials (RCTs) evaluating the effectiveness of interventions for the treatment of pregnant women with pregestational diabetes mellitus (PGDM).

Design

A consensus developmental study.

Setting

International.

Population

Two hundred and five stakeholders completed the first round.

Methods

The study consisted of three components. (1) A systematic review of the literature to produce a list of outcomes reported in RCTs assessing the effectiveness of interventions for the treatment of pregnant women with PGDM. (2) A three-round, online eDelphi survey to prioritise these outcomes by international stakeholders (including healthcare professionals, researchers and women with PGDM). (3) A consensus meeting where stakeholders from each group decided on the final COS.

Main outcome measures

All outcomes were extracted from the literature.

Results

We extracted 131 unique outcomes from 67 records meeting the full inclusion criteria. Of the 205 stakeholders who completed the first round, 174/205 (85%) and 165/174 (95%) completed rounds 2 and 3, respectively. Participants at the subsequent consensus meeting chose 19 outcomes for inclusion into the COS: trimester-specific haemoglobin A1c, maternal weight gain during pregnancy, severe maternal hypoglycaemia, diabetic ketoacidosis, miscarriage, pregnancy-induced hypertension, pre-eclampsia, maternal death, birthweight, large for gestational age, small for gestational age, gestational age at birth, preterm birth, mode of birth, shoulder dystocia, neonatal hypoglycaemia, congenital malformations, stillbirth and neonatal death.

Conclusions

This COS will enable better comparison between RCTs to produce robust evidence synthesis, improve trial reporting and optimise research efficiency in studies assessing treatment of pregnant women with PGDM.

165 key stakeholders have developed #Treatment #CoreOutcomes in pregnant women with #diabetes existing before pregnancy.

My Baby's Movements: a stepped wedge cluster randomised controlled trial to raise maternal awareness of fetal movements during pregnancy study protocol

Background

Stillbirth is a devastating pregnancy outcome that has a profound and lasting impact on women and families. Globally, there are over 2.6 million stillbirths annually and progress in reducing these deaths has been slow. Maternal perception of decreased fetal movements (DFM) is strongly associated with stillbirth. However, maternal awareness of DFM and clinical management of women reporting DFM is often suboptimal. The My Baby’s Movements trial aims to evaluate an intervention package for maternity services including a mobile phone application for women and clinician education (MBM intervention) in reducing late gestation stillbirth rates.

Methods/design

This is a stepped wedge cluster randomised controlled trial with sequential introduction of the MBM intervention to 8 groups of 3–5 hospitals at four-monthly intervals over 3 years.

The target population is women with a singleton pregnancy, without lethal fetal abnormality, attending for antenatal care and clinicians providing maternity care at 26 maternity services in Australia and New Zealand. The primary outcome is stillbirth from 28 weeks’ gestation. Secondary outcomes address: a) neonatal morbidity and mortality; b) maternal psychosocial outcomes and health-seeking behaviour; c) health services utilisation; d) women’s and clinicians’ knowledge of fetal movements; and e) cost. 256,700 births (average of 3170 per hospital) will detect a 30% reduction in stillbirth rates from 3/1000 births to 2/1000 births, assuming a significance level of 5%. Analysis will utilise generalised linear mixed models.

Discussion

Maternal perception of DFM is a marker of an at-risk pregnancy and commonly precedes a stillbirth. MBM offers a simple, inexpensive resource to reduce the number of stillborn babies, and families suffering the distressing consequences of such a loss. This large pragmatic trial will provide evidence on benefits and potential harms of raising awareness of DFM using a mobile phone app.

Trial registration

ACTRN12614000291684. Registered 19 March 2014.

Version

Protocol Version 6.1, February 2018.

AAV-Mediated Expression of Broadly Neutralizing and Vaccine-like Antibodies Targeting the HIV-1 Envelope V2 Region

HIV-1 infection continues to be a global health challenge and a vaccine is urgently needed. Broadly neutralizing antibodies (bNAbs) are considered essential as they inhibit multiple HIV-1 strains, but they are difficult to elicit by conventional immunization. In contrast, non-neutralizing antibodies that correlated with reduced risk of infection in the RV144 HIV vaccine trial are relatively easy to induce, but responses are not durable. To overcome these obstacles, adeno-associated virus (AAV) vectors were used to provide long-term expression of antibodies targeting the V2 region of the HIV-1 envelope protein, including the potent CAP256-VRC26.25 bNAb, as well as non-neutralizing CAP228 antibodies that resemble those elicited by vaccination. AAVs mediated effective antibody expression in cell culture and immunocompetent mice. Mean concentrations of human immunoglobulin G (IgG) in mouse sera increased rapidly following a single AAV injection, reaching 8–60 μg/mL for CAP256 antibodies and 44–220 μg/mL for CAP228 antibodies over 24 weeks, but antibody concentrations varied for individual mice. Secreted antibodies collected from serum retained the expected binding and neutralizing activity. The vectors generated here are, therefore, suitable for the delivery of V2-targeting HIV antibodies, and they could be used in a vectored immunoprophylaxis (VIP) approach to sustain the level of antibody expression required to prevent HIV infection.

Production and Immunogenicity of Soluble Plant-Produced HIV-1 Subtype C Envelope gp140 Immunogens

The development of effective vaccines is urgently needed to curb the spread of human immunodeficiency virus type 1 (HIV-1). A major focal point of current HIV vaccine research is the production of soluble envelope (Env) glycoproteins which reproduce the structure of the native gp160 trimer. These antigens are produced in mammalian cells, which requires a sophisticated infrastructure for manufacture that is mostly absent in developing countries. The production of recombinant proteins in plants is an attractive alternative for the potentially cheap and scalable production of vaccine antigens, especially for developing countries. In this study, we developed a transient expression system in Nicotiana benthamiana for the production of soluble HIV Env gp140 antigens based on two rationally selected virus isolates (CAP256 SU and Du151). The scalability of the platform was demonstrated and both affinity and size exclusion chromatography (SEC) were explored for recovery of the recombinant antigens. Rabbits immunized with lectin affinity-purified antigens developed high titres of binding antibodies, including against the V1V2 loop region, and neutralizing antibodies against Tier 1 viruses. The removal of aggregated Env species by gel filtration resulted in the elicitation of superior binding and neutralizing antibodies. Furthermore, a heterologous prime-boost regimen employing a recombinant modified vaccinia Ankara (rMVA) vaccine, followed by boosts with the SEC-purified protein, significantly improved the immunogenicity. To our knowledge, this is the first study to assess the immunogenicity of a near-full length plant-derived Env vaccine immunogen.

Nonprogressing HIV-infected children share fundamental immunological features of nonpathogenic SIV infection

Disease-free infection in HIV-infected adults is associated with human leukocyte antigen-mediated suppression of viremia, whereas in the sooty mangabey and other healthy natural hosts of simian immunodeficiency virus (SIV), viral replication continues unabated. To better understand factors preventing HIV disease, we investigated pediatric infection, where AIDS typically develops more rapidly than in adults. Among 170 nonprogressing antiretroviral therapy-naïve children aged >5 years maintaining normal-for-age CD4 T cell counts, immune activation levels were low despite high viremia (median, 26,000 copies/ml). Potent, broadly neutralizing antibody responses in most of the subjects and strong virus-specific T cell activity were present but did not drive pediatric nonprogression. However, reduced CCR5 expression and low HIV infection in long-lived central memory CD4 T cells were observed in pediatric nonprogressors. These children therefore express two cardinal immunological features of nonpathogenic SIV infection in sooty mangabeys-low immune activation despite high viremia and low CCR5 expression on long-lived central memory CD4 T cells-suggesting closer similarities with nonpathogenetic mechanisms evolved over thousands of years in natural SIV hosts than those operating in HIV-infected adults.

Efficient silencing of hepatitis B virus by helper-dependent adenovirus vector-mediated delivery of artificial antiviral primary micro RNAs

Hepatitis B virus (HBV) infection is endemic to southern Africa and parts of Asia where approximately 350 million individuals are chronically infected. Persistent infection increases risk for the serious complications of cirrhosis and hepatocellular carcinoma. Licensed HBV treatments rarely eradicate the virus, which makes developing new strategies for the treatment of chronic HBV a priority. Pol II-transcribed mono- and trimeric primary micro RNAs (primiRNAs) have previously been used to activate RNA interference (RNAi) and inhibit HBV gene expression, indicating that this approach holds promise for HBV therapy. Nevertheless, achieving safe and efficient delivery of anti-HBV RNAi expression cassettes remains an important objective before therapeutic application of this gene silencing technology is realized. Recombinant adenoviruses (Ads) are amongst the most efficient hepatotropic gene delivery vehicles, but a drawback of their use is transient transgene expression and toxicity that results from induction of host immune responses. To diminish immunostimulation of anti-HBV RNAi-activating vectors, helper-dependent (HD) Ads with all viral proteinencoding sequences removed from their genomes, were generated. A CMV Pol II promoter element was used to transcribe antiviral pri-miRNAs that target HBV. Processing of the anti-HBV pri-miRNA RNAi activators occurred according to intended design. Assessment in cultured cells and in a HBV transgenic model of the infection demonstrated that HD Ads delivered the silencing sequences efficiently and replication of the virus was inhibited without causing overt toxic effects. Collectively these data augur well for clinical use of HD Ads to deliver Pol II HBV-silencing cassettes to counter the persistent infection.

Inhibition of hepatitis B virus replication in vivo using lipoplexes containing altritol-modified antiviral siRNAs

Chronic infection with the hepatitis B virus (HBV) occurs in approximately 6% of the world's population and carriers of the virus are at risk for complicating hepatocellular carcinoma. Current treatment options have limited efficacy and chronic HBV infection is likely to remain a significant global medical problem for many years to come. Silencing HBV gene expression by harnessing RNA interference (RNAi) presents an attractive option for development of novel and effective anti HBV agents. However, despite significant and rapid progress, further refinement of existing technologies is necessary before clinical application of RNAi-based HBV therapies is realized. Limiting off target effects, improvement of delivery efficiency, dose regulation and preventing reactivation of viral replication are some of the hurdles that need to be overcome. To address this, we assessed the usefulness of the recently described class of altritol-containing synthetic siRNAs (ANA siRNAs), which were administered as lipoplexes and tested in vivo in a stringent HBV transgenic mouse model. Our observations show that ANA siRNAs are capable of silencing of HBV replication in vivo. Importantly, non specific immunostimulation was observed with unmodified siRNAs and this undesirable effect was significantly attenuated by ANA modification. Inhibition of HBV replication of approximately 50% was achieved without evidence for induction of toxicity. These results augur well for future application of ANA siRNA therapeutic lipoplexes.

Mode and timing of twin delivery and perinatal outcomes in low- and middle-income countries: a secondary analysis of the WHO Multicountry Survey on Maternal and Newborn Health

OBJECTIVE

To describe the mode and timing of delivery of twin pregnancies at ≥34 weeks of gestation and their association with perinatal outcomes.

DESIGN

Secondary analysis of a cross-sectional study.

POPULATION

Twin deliveries at ≥34 weeks of gestation from 21 low- and middle-income countries participating in the WHO Multicountry Survey on Maternal and Newborn Health.

METHODS

Descriptive analysis and effect estimates using multilevel logistic regression.

MAIN OUTCOME MEASURES

Stillbirth, perinatal mortality, and neonatal near miss (use of selected life saving interventions at birth).

RESULTS

The average length of gestation at delivery was 37.6 weeks. Of all twin deliveries, 16.8 and 17.6% were delivered by caesarean section before and after the onset of labour, respectively. Prelabour caesarean delivery was associated with older maternal age, higher institutional capacity and wealth of the country. Compared with spontaneous vaginal delivery, lower risks of neonatal near miss (adjusted odds ratio, aOR, 0.63; 95% confidence interval, 95% CI, 0.44-0.94) were found among prelabour caesarean deliveries. A lower risk of early neonatal mortality (aOR 0.12; 95% CI 0.02-0.56) was also observed among prelabour caesarean deliveries with nonvertex presentation of the first twin. The week of gestation with the lowest rate of prospective fetal death varied by fetal presentation: 37 weeks for vertex-vertex; 39 weeks for vertex-nonvertex; and 38 weeks for a nonvertex first twin.

CONCLUSIONS

The prelabour caesarean delivery rate among twins varied largely between countries, probably as a result of overuse of caesarean delivery in wealthier countries and limited access to caesarean delivery in low-income countries. Prelabour delivery may be beneficial when the first twin is nonvertex. International guidelines for optimal twin delivery methods are needed.

Inhibition of HBV replication in vivo using helper-dependent adenovirus vectors to deliver antiviral RNA interference expression cassettes

BACKGROUND

HBV is hyperendemic to southern Africa and parts of Asia, but licensed antivirals have little effect on limiting life-threatening complications of the infection. Although RNA interference (RNAi)-based gene silencing has shown therapeutic potential, difficulties with delivery of anti-HBV RNAi effectors remain an obstacle to their clinical use. To address concerns about the transient nature of transgene expression and toxicity resulting from immunostimulation by recombinant adenovirus vectors (Ads), utility of RNAi-activating anti-HBV helper-dependent (HD) Ads were assessed in this study.

METHODS

Following intravenous administration of 5×10(9) unmodified or pegylated HD Ad infectious particles to HBV transgenic mice, HBV viral loads and serum HBV surface antigen levels were monitored for 12 weeks. Immunostimulation of HD Ads was assessed by measuring inflammatory cytokines, hepatic function and immune response to the co-delivered LacZ reporter gene.

RESULTS

Unmodified and pegylated HD Ads transduced 80-90% of hepatocytes and expressed short hairpin RNAs (shRNAs) were processed to generate intended HBV-targeting guides. Markers of HBV replication were decreased by approximately 95% and silencing was sustained for 8 weeks. Unmodified HD Ads induced release of proinflammatory cytokines and there was evidence of an adaptive immune response to β-galactosidase. However the HD Ad-induced innate immune response was minimal in preparations that were enriched with infectious particles.

CONCLUSIONS

HD Ads have potential utility for delivery of therapeutic HBV-silencing sequences and alterations of these vectors to attenuate their immune responses may further improve their efficacy.

Therapeutic potential of adenoviral vectors for delivery of expressed RNAi activators

IMPORTANCE OF THE FIELD

Harnessing RNA interference (RNAi) to silence pathology-causing genes has shown promise as a mode of therapy. The sustained gene inhibition that may be achieved with expressed sequences is potentially useful for treatment of chronic viral infections, but efficient and safe delivery of these sequences remains a challenge. It is generally recognized that there is no ideal vector for all therapeutic RNAi applications, but recombinant adenovirus vectors are well suited to hepatic delivery of expressed RNAi activators.

AREAS COVERED IN THIS REVIEW

Adenoviruses are hepatotropic after systemic administration, and this is useful for delivering expressed RNAi activators that silence pathology-causing genes in the liver. However, drawbacks of adenoviruses are toxicity and diminished efficacy, which result from induction of innate and adaptive immune responses. In this review, the advantages and hurdles facing therapeutic application of adenoviral vectors for liver delivery of RNAi effectors are covered.

WHAT THE READER WILL GAIN

Insights into adenovirus vectorology and the methods that have been used to make these vectors safer for advancing clinical application of RNAi-based therapy.

TAKE HOME MESSAGE

Adenoviruses are very powerful hepatotropic vectors. To make adenoviruses more effective for clinical use, polymer conjugation and deletion of viral vector sequences have been used successfully. However, further modifications to attenuate immunostimulation as well as improvements in large-scale production are necessary before the therapeutic potential of adenovirus-mediated delivery of RNAi activators is realized.

Efficient inhibition of hepatitis B virus replication in vivo, using polyethylene glycol-modified adenovirus vectors

Achieving safe delivery of anti-hepatitis B virus (HBV) RNA interference (RNAi) effectors is an important objective of this gene-silencing technology. Adenoviruses (Ads) have a natural tropism for the liver after systemic administration, and are useful for delivery of expressed anti-HBV RNAi sequences. However, a drawback of Ad vectors is diminished efficacy and toxicity that results from stimulation of innate and adaptive immunity. To attenuate these effects we used monomethoxy polyethylene glycol-succinimidyl propionate (mPEG-SPA) to modify first-generation vectors that express an anti-HBV RNAi effector. Efficient hepatocyte transduction and knockdown of HBV replication were achieved after intravenous administration of 5 x 10(9) PEGylated or native recombinant Ads to HBV transgenic mice. After the first injection, circulating HBV viral particle equivalents (VPEs) remained low for 3 weeks and began to increase after 5 weeks. A second dose of PEGylated anti-HBV Ad caused a less sustained decrease in circulating VPEs, but no silencing after a second dose was observed in animals treated with unmodified vector. Release of inflammatory cytokines, including monocyte chemoattractant protein-1 (MCP-1), interferon-gamma, interleukin-6, and tumor necrosis factor-alpha, was elevated in animals receiving unmodified vectors. However, only a modest increase in MCP-1 was observed in mice that received a second dose of PEG Ads. Also, polymer-conjugated vectors induced a weaker adaptive immune response and were less hepatotoxic than their unmodified counterparts. Collectively, these observations show that PEG modification of Ads expressing RNAi effectors improves their potential for therapeutic application against HBV infection.

A valine to phenylalanine mutation in the precore region of hepatitis B virus causes intracellular retention and impaired secretion of HBe-antigen

AIM

Hepatitis B virus (HBV) e antigen (HBeAg) is translated from precore mRNA as a precore/core protein, which is post-translationally modified to give rise to the protein that is secreted into the serum. The G1862T mutation in HBV occurs in the bulge of the encapsidation signal within the pregenomic RNA. When the precore mRNA is translated, this mutation results in a valine to phenylalanine substitution at the -3 position to the signal peptide cleavage site at the amino end of the precursor protein. The aim of this study was to determine whether this mutation could affect HBV replication and/or HBeAg expression.

METHODS

Following transfection of Huh 7 cells, HBV replication was followed using real time polymerase reaction (PCR) and expression of HBeAg expression was monitored using confocal microscopy.

RESULTS

HBV replication was reduced when this mutation was introduced into genotype D but not into genotype A replication-competent constructs. Using mutant HBeAg-expressing plasmids, we demonstrated a 54% reduction in HBeAg secretion relative to the wild type. Confocal microscopy demonstrated that the mutant HBeAg accumulated in the endoplasmic reticulum, endoplasmic reticulum intermediate compartment and Golgi. These aggregates of mutant protein increased in size following treatment of the cells with a proteasome inhibitor, MG132, and had the hallmark features of aggresomes. They attracted ubiquitin, heat shock proteins and proteasomes and were isolated from the cytosol by the intermediate filaments, vimentin and cytokeratin.

CONCLUSION

The formation of aggresomes, as a result of the G1862T mutation, may play a contributory role in HBV-induced liver disease.

Expressed anti-HBV primary microRNA shuttles inhibit viral replication efficiently in vitro and in vivo

The use of RNA interference (RNAi) to inhibit gene expression is potentially applicable in the treatment of viral infections such as hepatitis B virus (HBV) persistence. Although efficient HBV gene silencing by short hairpin RNA (shRNA) expressed from RNA polymerase (Pol) III promoters has been reported, constitutive high-level transcription may cause harmful side effects. Here, we report an approach that allows the use of a Pol II promoter to improve transcription regulation of expressed RNAi effecters. Pol II [cytomegalovirus (CMV)] or Pol III (U6) promoter cassettes that transcribe anti-HBV primary microRNA (pri-miR)-122 and pri-miR-31 shuttles were generated. In cultured cells both types of pri-miR-like sequences effected knockdown of markers of viral replication (>80%) and were processed to form intended 21-nucleotide guides. The concentration of CMV-expressed miRs was approximately 85-fold lower than the U6 shRNA-derived guide RNA. When cells were co-transfected with pri-miR expression cassettes, attenuation of independent RNAi-mediated gene silencing was not observed, which is in contrast to the action of U6 shRNA expression cassettes. The efficacy of the anti-HBV pri-miR shuttles in vivo was verified using the murine hydrodynamic injection model. Employing Pol II-expressed pri-miR mimics may be useful in the treatment of HBV infection, and potentially also for generic application in RNAi-based therapy.

Specific inhibition of HBV replication in vitro and in vivo with expressed long hairpin RNA

Activating RNA interference to achieve specific gene silencing has shown promise for the development of RNA-based treatment of chronic hepatitis B virus (HBV) infection. To further this approach, we assessed the efficacy of expressed long hairpin RNAs (lhRNAs) that target the conserved HBx open reading frame of HBV. As substrates for Dicer, lhRNAs have the potential to generate multiple short interfering RNAs (siRNAs) to enable simultaneous targeting of different sites. Two U6 Pol III vectors were constructed that encode anti-HBV lhRNAs with a 62 base pair stem sequence containing multiple G:U pairings. Assessment in transfected cultured cells and also in vivo using the murine hydrodynamic injection model showed that one of the lhRNA vectors (lhRNA 1) diminished markers of virus replication by 70-90% without evidence of interferon response induction. Greatest silencing efficacy was observed for targets that are complementary to sequences located at the base of the hairpin stem and this correlated with a higher concentration of siRNAs derived from this region of the lhRNA. Although lhRNA 1 has the advantage of targeting a greater viral sequence, incomplete cellular processing may result in unequal silencing across the span of the viral target RNA.

Effective inhibition of HBV replication in vivo by anti-HBx short hairpin RNAs

Exploiting the RNA interference pathway has shown promise for developing novel and effective treatment of hepatitis B virus (HBV) infection. To advance this approach, we analyzed the antiviral efficacy of a panel of 10 Pol III U6 promoter-encoded short hairpin RNAs (shRNAs) that target conserved sequences of the oncogenic HBx open reading frame. To facilitate intracellular processing, the shRNAs included mismatches in the 25-bp stem region and a terminal loop of miRNA-23. Two shRNAs (shRNA 5 and shRNA 6) showed knockdown of HBV markers by 80-100% in transfected hepatocytes and also in a murine hydrodynamic injection model of HBV replication. Intracellular processing of hairpin RNA with the intended strand bias correlated with antiviral efficacy. Moreover, markers of HBV replication were inhibited without inducing genes associated with the nonspecific interferon response. To assess the antiviral efficacy of the shRNAs in a context that is similar to natural HBV infection, shRNA-encoding cassettes were tested against the virus in a HBV transgenic murine model. When delivered using recombinant adenovirus vectors, U6 shRNA 5 and U6 shRNA 6 mediated significant HBV knockdown. Collectively, these observations indicate that U6 shRNA 5 and U6 shRNA 6 are promising candidates for therapy of chronic HBV infection.

Antioxidants for preventing pre-eclampsia

BACKGROUND

Oxidative stress has been proposed as a key factor involved in the development of pre-eclampsia. Supplementing women with antioxidants during pregnancy may help to counteract oxidative stress and thereby prevent or delay the onset of pre-eclampsia.

OBJECTIVES

To determine the effectiveness and safety of any antioxidant supplementation during pregnancy and the risk of developing pre-eclampsia and its related complications.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (June 2004) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2004).

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing one or more antioxidants with either placebo or no antioxidants during pregnancy for the prevention of pre-eclampsia, and trials comparing one or more antioxidants with another, or with other interventions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, data extraction and trial quality. Data were double-entered into the Review Manager software.

MAIN RESULTS

Seven trials involving 6082 women are included in this review. The largest trial (5021 women) was quasi-random and only three of the seven included trials were rated high quality. Supplementing women with any antioxidants during pregnancy compared with control or placebo was associated with a 39% reduction in the risk of pre-eclampsia (relative risk (RR) 0.61, 95% confidence intervals (CI) 0.50 to 0.75, seven trials, 6082 women). Women receiving antioxidants compared with control or placebo also had a reduced risk of having a small-for-gestational-age infant (RR 0.64, 95% CI 0.47 to 0.87, three trials, 634 women), their infants had a greater mean birthweight (weighted mean difference 91.83 g, 95% CI 11.55 to 172.11, three trials, 451 women), but they were more likely to give birth preterm (RR 1.38, 95% CI 1.04 to 1.82, three trials, 583 women). There were insufficient data for reliable conclusions about possible effects on any other outcomes.

AUTHORS' CONCLUSIONS

These results should be interpreted with caution, as most of the data come from poor quality studies. Nevertheless, antioxidant supplementation seems to reduce the risk of pre-eclampsia. There also appears to be a reduction in the risk of having a small-for-gestational-age baby associated with antioxidants, although there is an increase in the risk of preterm birth. Several large trials are ongoing, and the results of these are needed before antioxidants can be recommended for clinical practice.

The placebo response and effect of time in a trial of acupuncture to treat nausea and vomiting in early pregnancy

OBJECTIVES

The sham control is widely used in acupuncture research, and its adequacy may be assessed by exploring the 'credibility' of the intervention. We aimed to examine the credibility of the study intervention, to quantify the size of the placebo response and effect of time in reducing nausea in early pregnancy.

DESIGN

Five hundred and ninety-three women with nausea or vomiting in early pregnancy volunteered to participate in a randomised controlled trial, conducted at the Women's and Children's Hospital, South Australia.

OUTCOME MEASURES

Women completed the Rhodes Index of Nausea and Vomiting and the Credibility Rating Scale.

RESULTS

The credibility of the acupuncture and sham acupuncture interventions were not different. The relative change in nausea at the end of the first week of the study was estimated to be 28% attributed to a time effect and 7% to the placebo response. At the end of the third week, there was a further small increase in time effect (32%) and the placebo response (17%).

CONCLUSION

Sham acupuncture is a credible control and allows assessment of the size of the placebo response.

Pregnancy outcome following women's participation in a randomised controlled trial of acupuncture to treat nausea and vomiting in early pregnancy

OBJECTIVES

Recent studies have concluded that acupuncture is safe in the hands of a qualified practitioner. This study assessed the risk of adverse effects of acupuncture administered during pregnancy.

METHODS

593 women with nausea and vomiting in early pregnancy volunteered to participate in a randomised controlled trial, conducted at the Women's and Children's Hospital, in South Australia. Patients were given either traditional acupuncture, formula acupuncture, sham acupuncture or no acupuncture.

OUTCOME MEASURES

Data were collected on perinatal outcome, congenital abnormalities, pregnancy complications and the newborn.

RESULTS

No differences were found between study groups in the incidence of perinatal outcome, congenital abnormalities, pregnancy complications and other infant outcomes.

CONCLUSION

Our findings suggest that no serious adverse effects arise from acupuncture administered in early pregnancy.

Perineal massage in labour and prevention of perineal trauma: randomised controlled trial

OBJECTIVE

To determine the effects of perineal massage in the second stage of labour on perineal outcomes.

DESIGN

Randomised controlled trial.

PARTICIPANTS

At 36 weeks' gestation, women expecting normal birth of a singleton were asked to join the study. Women became eligible to be randomised in labour if they progressed to full dilatation of the cervix or 8 cm or more if nulliparous or 5 cm or more if multiparous. 1340 were randomised into the trial.

INTERVENTION

Massage and stretching of the perineum during the second stage of labour with a water soluble lubricant.

MAIN OUTCOME MEASURES

PRIMARY OUTCOMES

rates of intact perineum, episiotomies, and first, second, third, and fourth degree tears.

SECONDARY OUTCOMES

pain at three and 10 days postpartum and pain, dyspareunia, resumption of sexual intercourse, and urinary and faecal incontinence and urgency three months postpartum.

RESULTS

Rates of intact perineums, first and second degree tears, and episiotomies were similar in the massage and the control groups. There were fewer third degree tears in the massage group (12 (1.7%) v 23 (3.6%); absolute risk 2.11, relative risk 0.45; 95% confidence interval 0.23 to 0.93, P<0.04), though the trial was underpowered to measure this rarer outcome. Groups did not differ in any of the secondary outcomes at the three assessment points.

CONCLUSIONS

The practice of perineal massage in labour does not increase the likelihood of an intact perineum or reduce the risk of pain, dyspareunia, or urinary and faecal problems.

The impact of nausea and vomiting on women: a burden of early pregnancy

Nausea and vomiting are troublesome symptoms occurring in the first trimester of pregnancy. The aim of this study was to describe the impact these symptoms have on women in early pregnancy by interviewing, using a structured questionnaire, 593 pregnant women presenting with nausea and vomiting in the first trimester of pregnancy. The women were asked to complete the Rhodes index of nausea and vomiting and the MOS 36 Short Form Health Survey (SF-36). Symptoms of nausea and vomiting started early in pregnancy. Nausea was the most troublesome symptom experienced by women, both in its duration and intensity. Low scores for the SF-36 were found for all items, particularly physical functioning, energy and social functioning. The women described substantial effects on working, household duties and parenting activities. Findings from this study suggest nausea and vomiting in early pregnancy has a profound impact on women's general sense of well-being and day to day life activities.

Universal antenatal group B streptococcus screening? The opinions of obstetricians and neonatologists within Australia

Group B streptococcus (GBS) is the leading infectious cause of morbidity and mortality in Australian newborns. Although intrapartum chemoprophylaxis is recommended to reduce the risk of neonatal GBS transmission and disease, controversy exists as to the best method to select women 'at risk' for this treatment. Our study aimed to survey the opinions of obstetricians and neonatologists currently in practice in Australia on GBS screening and treatment. Of the 488 obstetricians and 68 neonatologists currently in practice who responded to the survey, 271 obstetricians (56%) and 40 neonatologists (61%) supported universal antenatal screening. Of those respondents who did not support a universal antenatal screening policy, 196 (93%) and 24 (92%) of the obstetricians and neonatologists respectively, supported antenatal screening based on risk factors. This diversity in practitioner opinion highlights the lack of certainty in the literature as to the best management strategy to prevent neonatal GBS sepsis.

Patterns of medication use during and prior to pregnancy: the MAP study

We interviewed 140 pregnant women of any gestational age attending antenatal clinics at the Women's and Children's Hospital in Adelaide during September-October 1999 to elicit information about their patterns of medication use during and in the 3 months prior to their current pregnancy. Demographic information, information on women's prescribed, non-prescribed, and non-medicinal drug use during and in the 3 months prior to pregnancy, and information about both their general sources of information on medication use and their specific reasons for medication uptake/cessation during pregnancy were obtained. The women used an average of 0.7 0.8 prescribed and 2.3-2.6 non-prescribed medications (total 3.1-3.3) in the 3 pregnancy trimesters, compared with 1.0 prescribed and 2.2 non-prescribed prior to pregnancy. Use of a prescribed or non-prescribed medication was 96-97% across trimesters. Simple analgesics, vitamin/mineral supplements, and antacids were the most commonly taken medications. Antibiotics were the most commonly prescribed medication. Use of class A medications increased during pregnancy while use of non-class A medications decreased. Peri-conceptional folate supplementation was 31%. Alcohol consumption and cigarette smoking decreased after diagnosis of pregnancy. Both prescribed and non-prescribed medication use is common during all trimesters of pregnancy. However, overall use changes little compared with pre-pregnancy values. Rates of peri-conceptional folate supplementation are low.

Anti-D administration after childbirth for preventing Rhesus alloimmunisation

BACKGROUND

The development of Rh immunisation and its prophylactic use since the 1970s has meant that severe Rhesus D (RhD) alloimmunisation is now rarely seen.

OBJECTIVES

The objective of this systematic review was to assess the effects of giving anti-D to Rhesus negative women, with no anti-D antibodies, who had given birth to a Rhesus positive infant.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register, MEDLINE (from 1966 to January 1999) and reference lists of relevant articles. Date of last search of Cochrane Controlled Trials Register: January 1999.

SELECTION CRITERIA

Randomised trials in Rhesus negative women without antibodies who were given anti-D immunoglobulin postpartum compared with no treatment or placebo.

DATA COLLECTION AND ANALYSIS

Assessments of inclusion criteria, trial quality and data extraction were done by each author independently. Initial analyses included all trials. Other analyses assessed the effect of trial quality, ABO compatibility and dose.

MAIN RESULTS

Six eligible trials compared postpartum anti-D prophylaxis with no treatment or placebo. The trials involved over 10,000 women, but trial quality varied. Anti-D lowered the incidence of RhD alloimmunisation six months after birth (relative risk 0.04, 95% confidence interval 0.02 to 0.06), and in a subsequent pregnancy (relative risk 0.12, 95% confidence interval 0. 07 to 0.23). These benefits were seen regardless of the ABO status of the mother and baby and when anti-D was given within 72 hours of birth. Higher doses (up to 200 micro grams) were more effective than lower doses (up to 50 micro grams) in preventing RhD alloimmunisation in a subsequent pregnancy.

REVIEWER'S CONCLUSIONS

Anti-D, given within 72 hours after childbirth, reduces the risk of RhD alloimmunisation in Rhesus negative women who have given birth to a Rhesus positive infant. However the evidence on the optimal dose is limited.

Knee-chest postural management for breech at term: a randomized controlled trial

BACKGROUND

In 3 to 4 percent of all term births, the fetus presents as a breech. The objectives of this trial were to assess if assuming the knee-chest position reduced the frequency of breech presentation at delivery, increased the success of the subsequent external cephalic version, or both, and to determine if this management plan reduced the need for cesarean delivery.

METHODS

A randomized clinical trial recruited 100 women from two hospitals in Adelaide, South Australia, with a singleton breech presentation and a gestational age equal to or more than 36 weeks. Women in the treatment group were advised to assume the knee-chest position for 15 minutes three times a day for one week. Women in the control group did not perform postural management. All participants were reviewed one week later, and women whose baby remained as a breech presentation were offered an external cephalic version.

RESULTS

Postural management did not increase the success of the external cephalic version, reduce the frequency of breech presentation at delivery, or reduce the need for cesarean delivery in women with a breech presentation at term.

CONCLUSIONS

Findings from this trial included in a meta-analysis of postural management for breech presentation at term suggested that this is not an effective form of care to be offered routinely to women with a breech presentation at term.

A dark talent: silence in analysis

This paper is presented jointly by two analysts who have worked with patients whose silence stretched over years. They taxed our professional selves and our therapeutic repertoire of responses and techniques to the limit. Partly in response to these experiences, each analyst found herself needing to talk with another who could verify disturbing countertransference reactions from the standpoint of similar experience. The patients' (largely silent) attacks on analysis and their inability to use it conventionally constellated the need in us to talk, in an effort to relieve projected anxiety. Our conversations provided some containment of the destructive fantasies which we found developing in response to lack of verbal interaction with our patients. Unlike patients who project into an analyst in the unconscious hope of finding containment, silent patients project the need for containment, which they then disavow, leaving the analyst carrying the need, and feeling helpless, baffled and undermined in their therapeutic identity (Colman, private communication). In keeping with the theme of this conference, we found that our collaboration about what chronic analytic silence may mean helped to counteract its destructive effect on the analyst-patient relationship.

Foetal intracardiac transfusion for the treatment of severe anaemia due to human parvovirus B-19 infection

Intra-uterine parvovirus infection may result in severe foetal anaemia and death. Ultrasound diagnosis of foetal parvovirus is presented, together with ultrasound-guided foetal transfusion to treat the anaemia.

Thyrotropin-releasing hormone: does two hundred micrograms provide effective stimulation to the preterm fetal pituitary gland compared with four hundred micrograms?

OBJECTIVE

Our purpose was to compare the response of the fetal pituitary-thyroid axis to 200 and 400 micrograms of thyrotropin-releasing hormone administered to the mother immediately before delivery with a control group.

STUDY DESIGN

A randomized controlled trial was conducted of 26 women at gestational ages between 24 weeks and 33 weeks 6 days who had received one or more doses of betamethasone who were expected to be delivered within 1 to 4 hours. Women received either 200 or 400 micrograms of thyrotropin-releasing hormone or were in the control group.

RESULTS

Thyroid-stimulating hormone determinations on cord blood had a higher mean level in both treatment groups compared with the control group. No differences were seen in cord blood results between the two treatment groups for thyroid-stimulating hormone, thyroxine, triiodothyronine, free thyroxine, free triiodothyronine, and prolactin levels. The only other differences found were in a higher level in total thyroxine and a lower level of free thyroxine in the 400 micrograms thyrotropin-releasing hormone group compared with the 200 micrograms group in the 48-hour blood determinations.

CONCLUSION

Both 200 and 400 micrograms of thyrotropin-releasing hormone provided fetal pituitary stimulation, as reflected in fetal thyroid-stimulating hormone levels in cord blood, and both gave significantly higher levels compared with a control group.

The second stage of labour: durational dilemmas

The optimal management of prolonged second stage of labour remains a confused area of thought and action. This confusion is particularly evident when epidural analgesia is also being used. A review of the literature indicates that prolonged duration of the second stage, i.e. from full dilation of the cervix until delivery, with or without epidural analgesia, has little adverse effect on perinatal outcome. More attention should be paid to the expulsive phase of the second stage and greater efforts made to reduce unnecessary interventions.