The re-emergence of Zika in Brazil in 2020: a case of Guillain Barré Syndrome during the low season for arboviral infections

Seroprevalence of Zika in Brazil stratified by age and geographic distribution

Congenital Zika is a devastating consequence of maternal Zika virus infections. Estimates of age-dependent seroprevalence profiles are central to our understanding of the force of Zika virus infections. We set out to calculate the age-dependent seroprevalence of Zika virus infections in Brazil. We analyzed serum samples stratified by age and geographic location, collected from 2016 to 2019, from about 16,000 volunteers enrolled in a Phase 3 dengue vaccine trial led by the Institute Butantan in Brazil. Our results show that Zika seroprevalence has a remarkable age-dependent and geographical distribution, with an average age of the first infection varying from region to region, ranging from 4.97 (3.03–5.41) to 7.24 (6.98–7.90) years. The calculated basic reproduction number, , varied from region to region, ranging from 1.18 (1.04–1.41) to 2.33 (1.54–3.85). Such data are paramount to determine the optimal age to vaccinate against Zika, if and when such a vaccine becomes available.

Secondary metabolites as potential drug candidates against Zika virus, an emerging looming human threat: Current landscape, molecular mechanism and challenges ahead

Nature has given us yet another wild card in the form of Zika virus (ZIKV). It was found in 1947, but has only recently become an important public health risk, predominantly to pregnant women and their unborn offspring. Currently, no specific therapeutic agent exists for ZIKV and treatment is mainly supportive. Natural products (NPs) can serve as a major source of potent antiviral drugs. To create this review, a comprehensive search was conducted from different databases (PubMed, ScienceDirect, Google scholar). A statistical analysis on the number of publications related to NPs and ZIKV was conducted to analyse the trend in research covering the period 1980-2020. From the data collated in this review, a number of NPs have been found to be inhibitive towards different stages of the ZIKV lifecycle in in vitro studies. For instance, baicalin, (-)-epigallocatechin gallate, curcumin, nanchangmycin, gossypol, cephaeline, emetine, resveratrol, berberine, amongst others, can prevent viral entry by attacking ZIKV E protein. Compounds luteolin, myricetin, astragalin, rutin, (-)-epigallocatechin gallate, carnosine, pedalitin, amongst others, inhibited NS2B-NS3 protease activity which consequently hamper replication. Interestingly, a few NPs had the ability to arrest both viral entry and replication, namely baicalin, (-)-epigallocatechin gallate, curcumin, cephaeline, emetine, and resveratrol. To the best of our knowledge, we obtained only one in vivo study conducted on emetine and results showed that it decreased the levels of circulating ZIKV by approximately 10-fold. Our understanding on NPs exhibiting anti-ZIKV effects in in vivo testing as well as clinical trials is limited. Our trend analysis showed that interest in searching for a cure or prevention against Zika in NPs is negligible and there are no publications yet covering the clinical evaluation. NPs with anti-ZIKV property can a winning strategy in controlling the bio-burden of an epidemic or pandemic. We therefore opine that in the future, more research should be devoted to ZIKV. This review attempts to provide baseline data and roadmap to pursuit detailed investigations for developing potent and novel therapeutic agents to prevent and cure ZIKV infection.

The safety and immunogenicity of two Zika virus mRNA vaccine candidates in healthy flavivirus baseline seropositive and seronegative adults: the results of two randomised, placebo-controlled, dose-ranging, phase 1 clinical trials

BACKGROUND

Developing a safe and immunogenic vaccine against Zika virus remains an unmet medical need. We did two phase 1 studies that evaluated the safety and immunogenicity of two mRNA-based Zika virus vaccines (mRNA-1325 and mRNA-1893) in adults.

METHODS

Two randomised, placebo-controlled, dose-ranging, multicentre, phase 1 trials, one of mRNA-1325 (mRNA-1325 trial) and one of mRNA-1893 (mRNA-1893 trial), were done. For both studies, eligible participants were healthy adults (aged 18-49 years) who were flavivirus seronegative or flavivirus seropositive at baseline. Participants in the mRNA-1325 trial, which was done at three centres in the USA, were randomly assigned centrally (1:4), using a randomisation table, to the placebo group or one of three mRNA-1325 dose groups (10, 25, or 100 μg). All participants received two doses. The mRNA-1325 vaccine encoded the premembrane and envelope E structural proteins (prME) from a Micronesia 2007 Zika virus isolate. Participants in the mRNA-1893 trial, which was done at three centres in the USA and one centre in Puerto Rico, were randomly assigned (1:4) to the placebo group or one of four mRNA-1893 dose groups (10, 30, 100, or 250 μg) using centralised interactive response technology. All participants in the mRNA-1893 trial received dose one on day 1 and then dose two on day 29. The mRNA-1893 vaccine encoded the prME from the RIO-U1 Zika virus isolate. Safety was the primary outcome of each study, which was evaluated in the respective safety populations (mRNA-1325 trial: participants who received at least one dose and provided safety data; mRNA-1893 trial: participants who received at least one dose) and the solicited safety population (mRNA-1893 trial only: received at least 1 dose and contributed solicited adverse reaction data). Endpoints in both trials included solicited adverse reactions within 7 days after vaccination and unsolicited adverse events within 28 days after vaccination. The secondary outcome of both trials was immunogenicity assessed by Zika virus-specific neutralising antibodies (nAbs) in the per-protocol populations in either trial (participants with no major protocol deviations received full dose[s] of assigned dose level within the acceptable time window, had samples drawn within acceptable time window, and had prevaccination and corresponding post-vaccination serum samples for testing). These were descriptive studies, with no formal hypothesis testing in either trial. Both trials are registered with ClinicalTrials.gov, NCT03014089 (mRNA-1325 trial) and NCT04064905 (mRNA-1893 trial).

FINDINGS

The mRNA-1325 trial was done from Dec 14, 2016, to Aug 16, 2018. 90 participants were enrolled: 53 (59%) participants were women and 37 (41%) were men; 84 (93%) were White; and 74 (82%) were not Hispanic or Latino. All three dose levels of mRNA-1325 (10, 25, and 100 μg) were generally well tolerated, but the vaccine elicited poor Zika virus-specific nAb responses. At 28 days after dose two, geometric mean titres (GMTs) were highest for mRNA-1325 10 μg (10·3 [95% CI 5·9-18·2]). The mRNA-1893 trial was done from July 23, 2019, to March 22, 2021. 120 participants (70 [58%] women and 50 [42%] men) were enrolled, most participants were White (89 [74%]), and not Hispanic or Latino (91 [76%]). In the mRNA-1893 trial, solicited adverse reactions in participants who received a vaccine were mostly grade 1 or 2 and occurred more frequently at higher dose levels and after dose two. No participants withdrew due to an unsolicited treatment-emergent adverse event and most of these events were not treatment related. On day 57, all evaluated mRNA-1893 dose levels induced robust Zika virus-specific nAb responses, independent of flavivirus serostatus, that persisted until month 13. At day 57 in participants who were flavivirus seronegative, plaque reduction neutralisation titre test nAb GMTs were highest for mRNA-1893 100 μg (454·2 [330·0-619·6]); in participants who were flavivirus seropositive, GMTs were highest for mRNA-1893 10 μg (224·1 [43·5-1153·5]) and mRNA-1893 100 μg (190·5 [19·2-1887·2]).

INTERPRETATION

These findings support the continued development of mRNA-1893 against Zika virus, which was well tolerated at all evaluated dose levels and induced strong Zika virus-specific serum nAb responses after two doses, regardless of baseline flavivirus serostatus.

FUNDING

Biomedical Advanced Research and Development Authority and Moderna.

Rhizophora mucronata Lam., a halophyte from Mauritius Island, inhibits the entry of Zika virus in human cells (A549)- an in vitro and in silico analysis

The recent appearance of Zika virus (ZIKV) in Brazil should serve as a wake-up call to international authorities, as it poses a threat to global public health. In the present study, we investigated whether a mangrove plant, Rhizophora mucronata Lam. (R. mucronata) collected in Mauritius, possesses anti-ZIKV activity at the non-cytotoxic doses. ZIKVMC-MR766NIID (ZIKVGFP) was used for assessing anti ZIKV activity. In silico docking (Autodock 4) and molecular simulation were performed on collected data. Using a recombinant ZIKV expressing reporter green fluorescent protein(GFP) protein, we discovered that fruit and root methanolic, decocted fruit and root extracts were effective inhibitors of ZIKV infection in human epithelial A549 cells at negligible cytotoxicity. The mechanisms by which such extracts prevented ZIKV infection are linked to the inability of the virus to attach to the host cell surface. The outcomes of this study were supported by the docking calculations in which some of the dominant compounds have shown high binding affinity against ZIKV. The scientific data gathered in this study might pave the way for the future development of possible R. mucronata inhibitors to combat ZIKV.fCommunicated by Ramaswamy H. Sarma.

A randomized, placebo-controlled, blinded phase 1 study investigating a novel inactivated, Vero cell-culture derived Zika virus vaccine

BACKGROUND

Zika virus (ZIKV) is an emerging public health threat, rendering development of a safe and effective vaccine against the virus a high priority to face this unmet medical need. Our vaccine candidate has been developed on the same platform used for the licensed vaccine IXIARO®, a vaccine against Japanese Encephalitis virus, another closely related member of the Flaviviridae family.

METHODS

Between February 24, 2018 and November 16, 2018, we conducted a randomized, observer-blinded, placebo controlled, single center phase 1 study to assess the safety and immunogenicity of an adjuvanted, inactivated, purified whole-virus Zika vaccine candidate in the U.S. A total of 67 healthy flavivirus-naïve adults aged 18 to 49 years were randomly assigned to one of five study arms to receive two immunizations of either high dose or low dose (6 antigen units or 3 antigen units) with both dose levels applied in two different immunization regimens or placebo as control.

RESULTS

Our vaccine candidate showed an excellent safety profile independent of dose and vaccination regimen with predominantly mild adverse events. No serious adverse event has been reported. The ZIKV vaccine induced neutralizing antibodies in all tested doses and regimens with seroconversion rates up to 85.7% (high dose), which remained up to 40% (high dose) at 6 months follow-up. Of note, the rapid regimen triggered a substantial immune response within days.

CONCLUSIONS

The rapid development and production of a ZIKV vaccine candidate building on a commercial Vero-cell manufacturing platform resulted in a safe and immunogenic vaccine suitable for further clinical development. To optimize antibody persistence, higher doses and a booster administration might be considered.

Arboviral Infections in Neurological Disorders in Hospitalized Patients in São José do Rio Preto, São Paulo, Brazil

Arbovirus infections are increasingly important causes of disease, whose spectrum of neurological manifestations are not fully known. This study sought to retrospectively assess the incidence of arboviruses in cerebrospinal fluid samples of patients with neurological symptoms to inform diagnosis of central and peripheral nervous system disorders. A total of 255 cerebrospinal fluid (CSF) samples collected from January 2016 to December 2017 were tested for dengue virus (DENV 1-4), Zika virus (ZIKV), and Chikungunya virus (CHIKV) in addition to other neurotropic arboviruses of interest, using genetic and serologic assays. Of the 255 CSF samples analyzed, 3.53% (09/255) were positive for arboviruses presenting mainly as meningitis, encephalitis, and cerebrovascular events, of which ZIKV was detected in 2.74% (7/255), DENV in 0.78% (2/255), in addition to an identified ILHV infection that was described previously. All the cases were detected in adults aged 18 to 74 years old. Our findings highlight the scientific and clinical importance of neurological syndromes associated with arboviruses and demonstrate the relevance of specific laboratory methods to achieve accurate diagnoses as well as highlight the true dimension of these diseases to ultimately improve public health planning and medical case management.

The legacy of ZikaPLAN: a transnational research consortium addressing Zika

Global health research partnerships with institutions from high-income countries and low- and middle-income countries are one of the European Commission's flagship programmes. Here, we report on the ZikaPLAN research consortium funded by the European Commission with the primary goal of addressing the urgent knowledge gaps related to the Zika epidemic and the secondary goal of building up research capacity and establishing a Latin American-European research network for emerging vector-borne diseases. Five years of collaborative research effort have led to a better understanding of the full clinical spectrum of congenital Zika syndrome in children and the neurological complications of Zika virus infections in adults and helped explore the origins and trajectory of Zika virus transmission. Individual-level data from ZikaPLAN`s cohort studies were shared for joint analyses as part of the Zika Brazilian Cohorts Consortium, the European Commission-funded Zika Cohorts Vertical Transmission Study Group, and the World Health Organization-led Zika Virus Individual Participant Data Consortium. Furthermore, the legacy of ZikaPLAN includes new tools for birth defect surveillance and a Latin American birth defect surveillance network, an enhanced Guillain-Barre Syndrome research collaboration, a de-centralized evaluation platform for diagnostic assays, a global vector control hub, and the REDe network with freely available training resources to enhance global research capacity in vector-borne diseases.

Antecedent infections in Guillain-Barré syndrome in endemic areas of arbovirus transmission: A multinational case-control study

Half of the world's population is at risk of arthropod‐borne virus (arbovirus) infections. Several arbovirus infections have been associated with Guillain‐Barré syndrome (GBS). We investigated whether arboviruses are driving GBS beyond epidemic phases of transmission and studied the antibody response to glycolipids. The protocol of the International Guillain‐Barré syndrome Outcome Study (IGOS), an observational prospective cohort study, was adapted to a case‐control design. Serum samples were tested for a recent infection with Zika virus (ZIKV), dengue virus (DENV), chikungunya (CHIKV) virus, hepatitis E virus, Epstein‐Barr virus (EBV), cytomegalovirus (CMV), Campylobacter jejuni, and Mycoplasma pneumoniae, and for antibodies to glycolipids. Forty‐nine patients were included from Brazil (63%), Argentina (14%), and Malaysia (22%). Evidence of a recent infection was found in 27/49 (55%) patients: C jejuni (n = 15, 31%), M pneumoniae (n = 5, 10%), CHIKV (n = 2, 4%), EBV (n = 1, 2%), C jejuni and M pneumoniae (n = 2, 4%), CMV and DENV (n = 1, 2%), and C jejuni and DENV (n = 1, 2%). In 22 patients, 35 paired controls were collected. Odds ratio for recent infections did not significantly differ between cases and controls. No typical anti‐ganglioside antibody binding was associated with recent arbovirus infection. We conclude that arbovirus infections occur in GBS patients outside of epidemic viral transmission, although not significantly more than in controls. Broad infection and anti‐ganglioside antibody serology are important to establish the most likely pathogenic trigger in GBS patients. Larger studies are necessary to determine the association between arboviruses and GBS.

Bruguiera gymnorhiza (L.) Lam. at the Forefront of Pharma to Confront Zika Virus and Microbial Infections-An In Vitro and In Silico Perspective

The recent emergence of Zika virus (ZIKV) in Brazil and the increasing resistance developed by pathogenic bacteria to nearly all existing antibiotics should be taken as a wakeup call for the international authority as this represents a risk for global public health. The lack of antiviral drugs and effective antibiotics on the market triggers the need to search for safe therapeutics from medicinal plants to fight viral and microbial infections. In the present study, we investigated whether a mangrove plant, Bruguiera gymnorhiza (L.) Lam. (B. gymnorhiza) collected in Mauritius, possesses antimicrobial and antibiotic potentiating abilities and exerts anti-ZIKV activity at non-cytotoxic doses. Microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70603, methicillin-resistant Staphylococcus aureus ATCC 43300 (MRSA), Salmonella enteritidis ATCC 13076, Sarcina lutea ATCC 9341, Proteus mirabilis ATCC 25933, Bacillus cereus ATCC 11778 and Candida albicans ATCC 26555 were used to evaluate the antimicrobial properties. Ciprofloxacin, chloramphenicol and streptomycin antibiotics were used for assessing antibiotic potentiating activity. ZIKVMC-MR766NIID (ZIKVGFP) was used for assessing anti-ZIKV activity. In silico docking (Autodock 4) and ADME (SwissADME) analyses were performed on collected data. Antimicrobial results revealed that Bruguiera twig ethyl acetate (BTE) was the most potent extract inhibiting the growth of all nine microbes tested, with minimum inhibitory concentrations ranging from 0.19-0.39 mg/mL. BTE showed partial synergy effects against MRSA and Pseudomonas aeruginosa when applied in combination with streptomycin and ciprofloxacin, respectively. By using a recombinant ZIKV-expressing reporter GFP protein, we identified both Bruguiera root aqueous and Bruguiera fruit aqueous extracts as potent inhibitors of ZIKV infection in human epithelial A549 cells. The mechanisms by which such extracts prevented ZIKV infection are linked to the inability of the virus to bind to the host cell surface. In silico docking showed that ZIKV E protein, which is involved in cell receptor binding, could be a target for cryptochlorogenic acid, a chemical compound identified in B. gymnorhiza. From ADME results, cryptochlorogenic acid is predicted to be not orally bioavailable because it is too polar. Scientific data collected in this present work can open a new avenue for the development of potential inhibitors from B. gymnorhiza to fight ZIKV and microbial infections in the future.

Prior Heterologous Flavivirus Exposure Results in Reduced Pathogenesis in a Mouse Model of Zika Virus Infection

The 2015/2016 Zika virus epidemic in South and Central America left the scientific community urgently trying to understand the factors that contribute to Zika virus pathogenesis. Because multiple other flaviviruses are endemic in areas where Zika virus emerged, it is hypothesized that a key to understanding Zika virus disease severity is to study Zika virus infection in the context of prior flavivirus exposure. Human and animal studies have highlighted the idea that having been previously exposed to a different flavivirus may modulate the immune response to Zika virus. However, it is still unclear how prior flavivirus exposure impacts Zika viral burden and disease. In this murine study, we longitudinally examine multiple factors involved in Zika disease, linking viral burden with increased neurological disease severity, weight loss, and inflammation. We show that prior heterologous flavivirus exposure with dengue virus type 2 or 3 or the vaccine strain of yellow fever provides protection from mortality in a lethal Zika virus challenge. However, reduction in viral burden and Zika disease varies depending on the infecting primary flavivirus; with primary Zika virus infection being most protective from Zika virus challenge, followed by dengue virus 2, with yellow fever and dengue virus 3 protecting against mortality but showing more severe disease. This study demonstrates the variation in protective effects of prior flavivirus exposure on Zika virus pathogenesis and identifies distinct relationships between primary flavivirus infection and the potential for Zika virus disease.

IMPORTANCE The emergence and reemergence of various vector-borne diseases in recent years highlights the need to understand the mechanisms of protection for each pathogen. In this study, we investigated the impact of prior exposure to Zika virus, dengue virus serotypes 2 or 3, or the vaccine strain of yellow fever on pathogenesis and disease outcomes in a mouse model of Zika virus infection. We found that prior exposure to a heterologous flavivirus was protective from mortality, and to varying degrees, prior flavivirus exposure was protective against neurological disease, weight loss, and severe viral burden during a lethal Zika challenge. Using a longitudinal and cross-sectional study design, we were able to link multiple disease parameters, including viral burden, with neurological disease severity, weight loss, and inflammatory response in the context of flavivirus infection. This study demonstrates a measurable but varied impact of prior flavivirus exposure in modulating flavivirus pathophysiology. Given the cyclic nature of most flavivirus outbreaks, this work will contribute to the forecasting of disease severity for future outbreaks.

COVID-19, Chikungunya, Dengue and Zika Diseases: An Analytical Platform Based on MALDI-TOF MS, IR Spectroscopy and RT-qPCR for Accurate Diagnosis and Accelerate Epidemics Control

COVID-19 and arboviruses (ARBOD) epidemics co-occurrence is a great concern. In tropical and subtropical regions, ARBOD diseases such as chikungunya, dengue, and Zika are frequent. In both COVID-19 and ARBOD cases, an accurate diagnosis of infected patients is crucial to promote adequate treatment and isolation measures in COVID-19 cases. Overlap of clinical symptoms and laboratory parameters between COVID-19 and ARBOD present themselves as an extra challenge during diagnosis. COVID-19 diagnosis is mainly performed by quantitative reverse polymerase chain reaction (RT-qPCR), while ARBOD diagnosis is performed by serology, detection of antigen or antibody, and molecular diagnosis. In this review, the epidemiologic profile of arboviruses and SARS-CoV-2 is analyzed, and potential risks of symptom overlap is addressed. The implementation of an analytical platform based on infrared (IR) spectroscopy, MALDI-TOF mass spectrometry, and RT-qPCR is discussed as an efficient strategy for a fast, robust, reliable, and cost-effective diagnosis system even during the co-occurrence of virus outbreaks. The spectral data of IR spectroscopy and MALDI-TOF MS obtained from COVID-19 infected and recovered patients can be used to build up an integrated spectral database. This approach can enable us to determine quickly the groups that have been exposed and have recovered from COVID-19 or ARBOD, avoiding misdiagnoses.

Public health emergencies of international concern: a historic overview

RATIONALE

The International Health Regulations (IHR) have been the governing framework for global health security since 2007. Declaring public health emergencies of international concern (PHEIC) is a cornerstone of the IHR. Here we review how PHEIC are formally declared, the diseases for which such declarations have been made from 2007 to 2020 and justifications for such declarations.

KEY FINDINGS

Six events were declared PHEIC between 2007 and 2020: the 2009 H1N1 influenza pandemic, Ebola (West African outbreak 2013-2015, outbreak in Democratic Republic of Congo 2018-2020), poliomyelitis (2014 to present), Zika (2016) and COVID-19 (2020 to present). Poliomyelitis is the longest PHEIC. Zika was the first PHEIC for an arboviral disease. For several other emerging diseases a PHEIC was not declared despite the fact that the public health impact of the event was considered serious and associated with potential for international spread.

RECOMMENDATIONS

The binary nature of a PHEIC declaration is often not helpful for events where a tiered or graded approach is needed. The strength of PHEIC declarations is the ability to rapidly mobilize international coordination, streamline funding and accelerate the advancement of the development of vaccines, therapeutics and diagnostics under emergency use authorization. The ultimate purpose of such declaration is to catalyse timely evidence-based action, to limit the public health and societal impacts of emerging and re-emerging disease risks while preventing unwarranted travel and trade restrictions.

Dengue, chikungunya and Zika in GeoSentinel surveillance of international travellers: a literature review from 1995 to 2020

INTRODUCTION

GeoSentinel is a global surveillance network of travel medicine providers seeing ill-returned travellers. Much of our knowledge on health problems and infectious encountered by international travellers has evolved as a result of GeoSentinel surveillance, providing geographic and temporal trends in morbidity among travellers while contributing to improved pre-travel advice. We set out to synthesize epidemiological information, clinical manifestations and time trends for dengue, chikungunya and Zika in travellers as captured by GeoSentinel.

METHODS

We conducted a systematic literature search in PubMed on international travellers who presented with dengue, chikungunya or Zika virus infections to GeoSentinel sites around the world from 1995 until 2020.

RESULTS

Of 107 GeoSentinel publications, 42 articles were related to dengue, chikungunya and/or Zika. The final analyses and synthesis of and results presented here are based on the findings from 27 original articles covering the three arboviral diseases.

CONCLUSIONS

Dengue is the most frequent arboviral disease encountered in travellers presenting to GeoSentinel sites, with increasing trends over the past two decades. In Southeast Asia, annual proportionate morbidity increased from 50 dengue cases per 1000 ill returned travellers in non-epidemic years to an average of 159 cases per 1000 travellers during epidemic years. The highest number of travellers with chikungunya virus infections was reported during the chikungunya outbreak in the Americas and the Caribbean in the years 2013-16. Zika was first reported by GeoSentinel already in 2012, but notifications peaked in the years 2016-17 reflecting the public health emergency in the Americas at the time.