Correction: The Brazilian vaccine divide: How some municipalities were left behind in the Covid-19 vaccine coverage.

[This corrects the article DOI: 10.1371/journal.pgph.0002493.].

Dynamic transmission modeling of COVID-19 to support decision-making in Brazil: A scoping review in the pre-vaccine era.

Brazil was one of the countries most affected during the first year of the COVID-19 pandemic, in a pre-vaccine era, and mathematical and statistical models were used in decision-making and public policies to mitigate and suppress SARS-CoV-2 dispersion. In this article, we intend to overview the modeling for COVID-19 in Brazil, focusing on the first 18 months of the pandemic. We conducted a scoping review and searched for studies on infectious disease modeling methods in peer-reviewed journals and gray literature, published between January 01, 2020, and June 2, 2021, reporting real-world or scenario-based COVID-19 modeling for Brazil. We included 81 studies, most corresponding to published articles produced in Brazilian institutions. The models were dynamic and deterministic in the majority. The predominant model type was compartmental, but other models were also found. The main modeling objectives were to analyze epidemiological scenarios (testing interventions' effectiveness) and to project short and long-term predictions, while few articles performed economic impact analysis. Estimations of the R0 and transmission rates or projections regarding the course of the epidemic figured as major, especially at the beginning of the crisis. However, several other outputs were forecasted, such as the isolation/quarantine effect on transmission, hospital facilities required, secondary cases caused by infected children, and the economic effects of the pandemic. This study reveals numerous articles with shared objectives and similar methods and data sources. We observed a deficiency in addressing social inequities in the Brazilian context within the utilized models, which may also be expected in several low- and middle-income countries with significant social disparities. We conclude that the models were of great relevance in the pandemic scenario of COVID-19. Nevertheless, efforts could be better planned and executed with improved institutional organization, dialogue among research groups, increased interaction between modelers and epidemiologists, and establishment of a sustainable cooperation network.

The Brazilian vaccine divide: How some municipalities were left behind in the Covid-19 vaccine coverage.

This study aims to assess the progress of geographic, socioeconomic, and demographic disparities in Covid-19 vaccination coverage in Brazil over the first two years of the vaccination campaign. Data from the National Immunization Program Information System were used to estimate covid-19 vaccine coverage. Brazilian municipalities were divided into two groups based on their vaccine coverage for the booster dose. The first group comprised 20% of municipalities with the lowest coverage, while the second group (80% of municipalities) had higher coverage. The analysis was conducted separately for four age groups: 5-11, 12-17, 18-59, and 60+. Explanatory variables included socioeconomic and health services indicators. Crude and adjusted logistic regression models were used to estimate the probability of a municipality being among those with the worst vaccination coverage according to the categories of exploratory variables. Between January/2021 and December/2022, Brazil administered 448.2 million doses of the covid-19 vaccine. The booster vaccination coverage varied from 24.8% among adolescents to 79.7% among the elderly. The difference between the group with the highest and lowest coverage increased during the national vaccination campaign. Municipalities with lower education levels, higher proportion of Black population, higher Gini index, and worse health service indicators had a greater likelihood of having lower vaccination coverage. High and increasing levels of inequality in Covid-19 vaccination were observed in Brazil across all age groups during the vaccination campaign in 2021-2022.

One piece of the puzzle: Modeling vector presence and environment reveals seasonality, distribution, and prevalence of sandflies and Leishmania in an expansion area.

The recent geographic spread of Leishmania infantum along the borders of Argentina, Brazil and Paraguay has been highlighted. In our previous study, Lutzomyia longipalpis was found in 55 of 123 patches surveyed, and in some patches, sandflies were found at higher densities, forming hotspots. Based on the One Health approach, we investigated the seasonality of the vector, the presence of parasite DNA, and the environmental factors that contribute to vector and parasite dispersal in these previously described hotspots in Foz do Iguaçu, Brazil. Entomological surveys were conducted monthly for one year. Fourteen hotspots peridomicile and six intradomicile were sampled. PCR was used to assess the prevalence of Leishmania DNA in sandflies. Zero-inflated negative binomial regression was used to determine the association of micro- and mesoscale environmental variables with the occurrence and abundance of the three most abundant sandfly species sampled. A total of 3543 species were captured, with Lutzomyia longipalpis being the predominant species (71.78%) of the 13 species found. Evandromyia edwardsi, Expapillata firmatoi, Micropygomyia ferreirana and Pintomyia christenseni were reported for the first time in the region. NDVI, distance to water, precipitation, west-to-east wind, wind speed, maximum and minimum relative humidity, and sex were significant variables associated with vector presence/abundance in the environment. Vector presence/abundance in the peridomicile was associated with precipitation, altitude, maximum temperature, minimum and maximum relative humidity, west-to-east wind, wind speed, and sex. Leishmania DNA was detected in an average of 21% of Lu. longipalpis throughout the year. Vector abundance is concentrated in urban and peri-urban areas, with some specimens present in different parts of the city and some sites with high vector abundance. This distribution suggests that the risk of actual contact between humans and parasite vectors in urban areas during the epidemic period is associated with patches of peri-urban vegetation and then extends into urban areas.

Uncovering inequities in Covid-19 vaccine coverage for adults and elderly in Brazil: A multilevel study of 2021-2022 data.

Vaccination is crucial for reducing severe COVID-19 cases, hospitalizations, and deaths. However, vaccine access disparities within countries, particularly in low- and middle-income nations, may leave disadvantaged regions and populations behind. This study aimed to investigate potential inequalities in vaccine coverage among Brazilian aged 18 years and older based on demographic, geographic, and socioeconomic characteristics at the municipal level. A total of 389 million vaccination records from the National Immunization Program Information System were analyzed to calculate vaccine coverage rates for the first, second, and booster doses among adults (18-59 years) and elderly (60 + years) vaccinated between January 2021 and December 2022. We analyzed the data by gender and used a three-level (municipalities, states, regions) multilevel regression analysis to assess the association between vaccine coverage and municipal characteristics. Vaccination coverage was higher among the elderly than among adults, particularly for the second and booster doses. Adult women showed higher coverage rates than men (ranging from 118 % to 25 % higher along the analyzed period). Significant inequalities were observed when analyzing the evolution of vaccination coverage by sociodemographic characteristics of municipalities. In the early stages of the vaccination campaign, municipalities with higher per capita Gross Domestic Product (pGDP), educational level, and fewer Black residents reached higher population coverages earlier. In December 2022, adult and elderly booster vaccine coverage was 43 % and 19 %, respectively, higher in municipalities in the highest quintile of educational level. Higher vaccine uptake was also observed in municipalities with fewer Black residents and higher pGDP. Municipalities accounted for most of the variance in vaccine coverage (59.7 %-90.4 % depending on the dose and age group). This study emphasizes the inadequate booster coverage and the presence of socioeconomic and demographic disparities in COVID-19 vaccination rates. These issues must be addressed through equitable interventions to avoid potential disparities in morbidity and mortality.

Modeling the impact of child vaccination (5-11 y) on overall COVID-19 related hospitalizations and mortality in a context of omicron variant predominance and different vaccination coverage paces in Brazil.

Background: Developing countries have experienced significant COVID-19 disease burden. With the emergence of new variants, particularly omicron, the disease burden in children has increased. When the first COVID-19 vaccine was approved for use in children aged 5-11 years of age, very few countries recommended vaccination due to limited risk-benefit evidence for vaccination of this population. In Brazil, ranking second in the global COVID-19 death toll, the childhood COVID-19 disease burden increased significantly in early 2022. This prompted a risk-benefit assessment of the introduction and scaling-up of COVID-19 vaccination of children. Methods: To estimate the potential impact of vaccinating children aged 5-11 years with mRNA-based COVID-19 vaccine in the context of omicron dominance, we developed a discrete-time SEIR-like model stratified in age groups, considering a three-month time horizon. We considered three scenarios: No vaccination, slow, and maximum vaccination paces. In each scenario, we estimated the potential reduction in total COVID-19 cases, hospitalizations, deaths, hospitalization costs, and potential years of life lost, considering the absence of vaccination as the base-case scenario. Findings: We estimated that vaccinating at a maximum pace could prevent, between mid-January and April 2022, about 26,000 COVID-19 hospitalizations, and 4200 deaths in all age groups; of which 5400 hospitalizations and 410 deaths in children aged 5-11 years. Continuing vaccination at a slow/current pace would prevent 1450 deaths and 9700 COVID-19 hospitalizations in all age groups in this same time period; of which 180 deaths and 2390 hospitalizations in children only. Interpretation: Maximum vaccination of children results in a significant reduction of COVID-19 hospitalizations and deaths and should be enforced in developing countries with significant disease incidence in children. Funding: This manuscript was funded by the Brazilian Council for Scientific and Technology Development (CNPq - Process # 402834/2020-8).

Estimating the impact of implementation and timing of the COVID-19 vaccination programme in Brazil: a counterfactual analysis.

Background: Vaccines developed between 2020 and 2021 against the SARS-CoV-2 virus were designed to diminish the severity and prevent deaths due to COVID-19. However, estimates of the effectiveness of vaccination campaigns in achieving these goals remain a methodological challenge. In this work, we developed a Bayesian statistical model to estimate the number of deaths and hospitalisations averted by vaccination of older adults (above 60 years old) in Brazil. Methods: We fit a linear model to predict the number of deaths and hospitalisations of older adults as a function of vaccination coverage in this group and casualties in younger adults. We used this model in a counterfactual analysis, simulating alternative scenarios without vaccination or with faster vaccination roll-out. We estimated the direct effects of COVID-19 vaccination by computing the difference between hypothetical and realised scenarios. Findings: We estimated that more than 165,000 individuals above 60 years of age were not hospitalised due to COVID-19 in the first seven months of the vaccination campaign. An additional contingent of 104,000 hospitalisations could have been averted if vaccination had started earlier. We also estimated that more than 58 thousand lives were saved by vaccinations in the period analysed for the same age group and that an additional 47 thousand lives could have been saved had the Brazilian government started the vaccination programme earlier. Interpretation: Our estimates provided a lower bound for vaccination impacts in Brazil, demonstrating the importance of preventing the suffering and loss of older Brazilian adults. Once vaccines were approved, an early vaccination roll-out could have saved many more lives, especially when facing a pandemic. Funding: The Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brazil (Finance Code 001 to F.M.D.M. and L.S.F.), Conselho Nacional de Desenvolvimento Científico e Tecnológico - Brazil (grant number: 315854/2020-0 to M.E.B., 141698/2018-7 to R.L.P.d.S., 313055/2020-3 to P.I.P., 311832/2017-2 to R.A.K.), Fundação de Amparo à Pesquisa do Estado de São Paulo - Brazil (contract number: 2016/01343-7 to R.A.K.), Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro - Brazil (grant number: E-26/201.277/2021 to L.S.B.) and Inova Fiocruz/Fundação Oswaldo Cruz - Brazil (grant number: 48401485034116) to L.S.B., O.G.C. and M.G.d.F.C. The funding agencies had no role in the conceptualization of the study.

Modelling the impact of school reopening and contact tracing strategies on Covid-19 dynamics in different epidemiologic settings in Brazil.

We simulate the impact of school reopening during the COVID-19 pandemic in three major urban centers in Brazil to identify the epidemiological indicators and the best timing for the return of in-school activities and the effect of contact tracing as a mitigation measure. Our goal is to offer guidelines for evidence-based policymaking. We implement an extended SEIR model stratified by age and considering contact networks in different settings - school, home, work, and community, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening, and also estimate the number of hospitalization and deaths averted by the implementation of contact tracing. Reopening schools results in a non-linear increase in reported COVID-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects in reducing the total number of hospitalizations and deaths. Policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. While contact tracing strategies prevent new infections within school environments, they alone are not sufficient to avoid significant impacts on community transmission.

Modelling optimal vaccination strategies against COVID-19 in a context of Gamma variant predominance in Brazil.

INTRODUCTION: Brazil experienced moments of collapse in its health system throughout 2021, driven by the emergence of variants of concern (VOC) combined with an inefficient initial vaccination strategy against Covid-19. OBJECTIVES: To support decision-makers in formulating COVID-19 immunization policy in the context of limited vaccine availability and evolving variants over time, we evaluate optimal strategies for Covid-19 vaccination in Brazil in 2021, when vaccination was rolled out during Gamma variant predominance. METHODS: Using a discrete-time epidemic model we estimate Covid-19 deaths averted, considering the currently Covid-19 vaccine products and doses available in Brazil; vaccine coverage by target population; and vaccine effectiveness estimates. We evaluated a 5-month time horizon, from early August to the end of December 2021. Optimal vaccination strategies compared the outcomes in terms of averted deaths when varying dose intervals from 8 to 12 weeks, and choosing the minimum coverage levels per age group required prior to expanding vaccination to younger target populations. We also estimated dose availability required over time to allow the implementation of optimal strategies. RESULTS: To maximize the number of averted deaths, vaccine coverage of at least 80 % should be reached in older age groups before starting vaccination into subsequent younger age groups. When evaluating varying dose intervals for AZD1222, reducing the dose interval from 12 to 8 weeks for the primary schedule would result in fewer COVID-19 deaths, but this can only be implemented if accompanied by an increase in vaccine supply of at least 50 % over the coming six-months in Brazil. CONCLUSION: Covid-19 immunization strategies should be tailored to local vaccine product availability and supply over time, circulating variants of concern, and vaccine coverage in target population groups. Modelling can provide valuable and timely evidence to support the implementation of vaccination strategies considering the local context, yet following international and regional technical evidence-based guidance.

Assessing the best time interval between doses in a two-dose vaccination regimen to reduce the number of deaths in an ongoing epidemic of SARS-CoV-2.

The SARS-CoV-2 pandemic is a major concern all over the world and, as vaccines became available at the end of 2020, optimal vaccination strategies were subjected to intense investigation. Considering their critical role in reducing disease burden, the increasing demand outpacing production, and that most currently approved vaccines follow a two-dose regimen, the cost-effectiveness of delaying the second dose to increment the coverage of the population receiving the first dose is often debated. Finding the best solution is complex due to the trade-off between vaccinating more people with lower level of protection and guaranteeing higher protection to a fewer number of individuals. Here we present a novel extended age-structured SEIR mathematical model that includes a two-dose vaccination schedule with a between-doses delay modelled through delay differential equations and linear optimization of vaccination rates. By maintaining the minimum stock of vaccines under a given production rate, we evaluate the dose interval that minimizes the number of deaths. We found that the best strategy depends on an interplay between the vaccine production rate and the relative efficacy of the first dose. In the scenario of low first-dose efficacy, it is always better to vaccinate the second dose as soon as possible, while for high first-dose efficacy, the best strategy of time window depends on the production rate and also on second-dose efficacy provided by each type of vaccine. We also found that the rate of spread of the infection does not affect significantly the thresholds of the best window, but is an important factor in the absolute number of total deaths. These conclusions point to the need to carefully take into account both vaccine characteristics and roll-out speed to optimize the outcome of vaccination strategies.

Percolation across households in mechanistic models of non-pharmaceutical interventions in SARS-CoV-2 disease dynamics.

Since the emergence of the novel coronavirus disease 2019 (COVID-19), mathematical modelling has become an important tool for planning strategies to combat the pandemic by supporting decision-making and public policies, as well as allowing an assessment of the effect of different intervention scenarios. A proliferation of compartmental models were developed by the mathematical modelling community in order to understand and make predictions about the spread of COVID-19. While compartmental models are suitable for simulating large populations, the underlying assumption of a well-mixed population might be problematic when considering non-pharmaceutical interventions (NPIs) which have a major impact on the connectivity between individuals in a population. Here we propose a modification to an extended age-structured SEIR (susceptible-exposed-infected-recovered) framework, with dynamic transmission modelled using contact matrices for various settings in Brazil. By assuming that the mitigation strategies for COVID-19 affect the connections among different households, network percolation theory predicts that the connectivity among all households decreases drastically above a certain threshold of removed connections. We incorporated this emergent effect at population level by modulating home contact matrices through a percolation correction function, with the few additional parameters fitted to hospitalisation and mortality data from the city of São Paulo. Our model with percolation effects was better supported by the data than the same model without such effects. By allowing a more reliable assessment of the impact of NPIs, our improved model provides a better description of the epidemiological dynamics and, consequently, better policy recommendations.

Gradual increase of temperature trigger metabolic and oxidative responses in plasma and body tissues in the Antarctic fish Notothenia rossii.

Antarctica is considered a thermally stable ecosystem; however, climate studies point to increases in water temperatures in this region. These thermal changes may affect the biological processes and promote metabolic changes in the adapted organisms that live in this region, rendering the animals more vulnerable to oxidative damage. This study assessed the effect of acclimation temperature on the levels of stress response markers in plasma, kidney, gill, liver, and brain tissues of Notothenia rossii subjected to gradual temperature changes of 0.5 °C/day until reaching temperatures of 2, 4, 6, and 8 °C. Under the effect of the 0.5 °C/day acclimation rate, gill tissue showed increased glutathione-S-transferase (GST) activity; kidney tissue showed increased H+-ATPase activity. In the liver, there was also an increase in GSH. In plasma, gradual decreases in the concentrations of total proteins and globulins were observed. These responses indicate a higher production of reactive oxygen species ROS, an imbalance in energy demand, and a lack in protein synthesis. Gradual increase in temperature may cause opposite responses to the thermal shock model in N. rossii.

Consumers' active choice behaviour promotes coevolutionary units in antagonistic networks.

Individual behaviour and local context can influence the evolution of ecological interactions and how they structure into networks. In trophic interactions, consumers can increase their fitness by actively choosing resources that they are more likely to explore successfully. Mathematical modelling is often employed in theoretical studies to understand the coevolutionary dynamics between consumers and resources. However, they often disregard the individual consumer behaviour since the complexity of these systems usually requires simplifying assumptions about interaction details. Using an individual-based model, we model a community of several species that interact antagonistically. Each individual has a trait (attack or defence) that is explicitly modelled and the probability of the interaction to occur successfully increases with increased trait-matching. In addition, consumers can actively choose resources that guarantee greater fitness. We show that active consumer choice can generate coevolutionary units over time. It means that the traits of both consumers and resources converge into multiple groups with similar traits and the species interactions stay restricted to these groups over time. We also observed that network structure is more dependent on the parameter that delimits active consumer choice than on the intensity of selective pressure. Thus, our results support the idea that consumer active choice behaviour plays an important role in the ecological and evolutionary processes that structure interacting communities.

Brazil in the face of new SARS-CoV-2 variants: emergencies and challenges in public health.

This article discusses the epidemic situation of Covid-19 in Brazil, in the face of the emergence of a new strain called P.1, which is more transmissible and may be associated with reinfection. Given the collapse of hospital care in Manaus in January 2021 and the results of three recent preprints, each that reports increased transmissibility of the P.1 variant, we propose some urgent measures. Genomic surveillance based on multi-step diagnostics, starting with RT-PCR type tests and up to sequencing, should be established. Efforts to identify reinfections associated with this variant and the update of its definition in protocols should be prioritized, and studies on the efficacy of currently available vaccines in Brazil concerning the new variant should be conducted. We also propose improving the Brazilian health surveillance system such that genomic surveillance is coordinated and thereby better able to respond to future emergencies in a more timely fashion. We call on the public agents involved in health surveillance to share data and information regarding the epidemic in a clear, fast and transparent way. Finally, we propose a greater engagement in inter-institutional cooperation of all those involved in the response and production of knowledge about the pandemic in our country.

Letter to the Scientific Community: Brazil in face of the new SARS-CoV-2 variants / Carta à Comunidade Científica: o Brasil frente às novas variantes de SARSCoV- 2

This letter discusses the epidemic situation of Covid-19 in Brazil, in the face of the emergence of a new strain, called P1, more transmissible and with possible associated reinfection.  Given the collapse of hospital care in Manaus in January 2021 and the results of three recent preprints, all of which found increased transmissibility of the P.1 variant, we propose some urgent actions: the establishment of genomic surveillance based on multi-step diagnostics, starting with RT-PCR type tests  to sequencing; an immediate effort to identify reinfections associated with the new variant, updating its definition protocols; and studies on the efficacy of currently available vaccines in Brazil in respect to the new variant.  We also propose the improvement of the Brazilian health surveillance system, which should be articulated with genomic surveillance, in order to respond more timely to future emergencies. We call on the public agents involved in health surveillance to share data and information regarding the epidemic in a clear, fast and transparent way. Finally, we propose a greater engagement in inter-institutional cooperation of all those involved in the response and production of knowledge about the pandemic in our country.

Esta carta discute a situação epidêmica da Covid-19 no Brasil frente aoaparecimento de uma nova linhagem, chamada P1, mais transmissível e compossível re-infecção associada. Tendo em vista o colapso do atendimentohospitalar em Manaus em janeiro de 2021 e os resultados de três preprintsrecentes, todos encontrando maior transmissibilidade da variante P.1, propomos algumas ações urgentes: o estabelecimento de uma vigilância genômica baseada em diagnóstico em múltiplos passos, iniciando com os testes do tipo RT-PCR até o sequenciamento; um esforço imediato na identificação de re-infecções associadas à nova variante, atualizando os seus protocolos de definição; e estudos sobre a eficácia das vacinas atualmente disponíveis no Brasil na vigência da nova variante. Propomos, ademais, o aprimoramento do sistema de vigilância em saúde brasileiro, que seja articulado com a vigilância genômica, de forma a responder mais oportunamente a emergências futuras. Chamamos os agentes públicos implicados na vigilância em saúde para que compartilhem dados e informações referentes à epidemia de forma clara, rápida e transparente. Finalmente propomos um maior engajamento na cooperação inter-institucional de todos os envolvidos na resposta e produção de conhecimento sobre a pandemia em nosso país.

Model-based estimation of transmissibility and reinfection of SARS-CoV-2 P.1 variant.

Background: The SARS-CoV-2 variant of concern (VOC) P.1 (Gamma variant) emerged in the Amazonas State, Brazil, in November 2020. The epidemiological consequences of its mutations have not been widely studied, despite detection of P.1 in 36 countries, with local transmission in at least 5 countries. A range of mutations are seen in P.1, ten of them in the spike protein. It shares mutations with VOCs previously detected in the United Kingdom (B.1.1.7, Alpha variant) and South Africa (B.1.351, Beta variant). Methods: We estimated the transmissibility and reinfection of P.1 using a model-based approach, fitting data from the national health surveillance of hospitalized individuals and frequency of the P.1 variant in Manaus from December-2020 to February-2021. Results: Here we estimate that the new variant is about 2.6 times more transmissible (95% Confidence Interval: 2.4-2.8) than previous circulating variant(s). Manaus already had a high prevalence of individuals previously affected by the SARS-CoV-2 virus and our fitted model attributed 28% of Manaus cases in the period to reinfections by P.1, confirming the importance of reinfection by this variant. This value is in line with estimates from blood donors samples in Manaus city. Conclusions: Our estimates rank P.1 as one of the most transmissible among the SARS-CoV-2 VOCs currently identified, and potentially as transmissible as the posteriorly detected VOC B.1.617.2 (Delta variant), posing a serious threat and requiring measures to control its global spread.

Brazil in the face of new SARS-CoV-2 variants: emergencies and challenges in public health / O Brasil perante as novas variantes de SARS-CoV-2: emergências e desafios em saúde pública

ABSTRACT: This article discusses the epidemic situation of Covid-19 in Brazil, in the face of the emergence of a new strain called P.1, which is more transmissible and may be associated with reinfection. Given the collapse of hospital care in Manaus in January 2021 and the results of three recent preprints, each that reports increased transmissibility of the P.1 variant, we propose some urgent measures. Genomic surveillance based on multi-step diagnostics, starting with RT-PCR type tests and up to sequencing, should be established. Efforts to identify reinfections associated with this variant and the update of its definition in protocols should be prioritized, and studies on the efficacy of currently available vaccines in Brazil concerning the new variant should be conducted. We also propose improving the Brazilian health surveillance system such that genomic surveillance is coordinated and thereby better able to respond to future emergencies in a more timely fashion. We call on the public agents involved in health surveillance to share data and information regarding the epidemic in a clear, fast and transparent way. Finally, we propose a greater engagement in inter-institutional cooperation of all those involved in the response and production of knowledge about the pandemic in our country.

RESUMO: Este artigo discute a situação epidêmica da COVID-19 no Brasil diante do aparecimento de uma nova linhagem, chamada P.1, mais transmissível e com possível reinfecção associada. Tendo em vista o colapso do atendimento hospitalar em Manaus em janeiro de 2021 e os resultados de três preprints recentes, dos quais todos encontraram maior transmissibilidade da variante P.1, propomos algumas ações urgentes: o estabelecimento de uma vigilância genômica baseada em diagnóstico em múltiplos passos, iniciando com os testes do tipo transcrição reversa seguida de reação em cadeia da polimerase (RT-PCR) até o sequenciamento; um esforço imediato na identificação de reinfecções associadas à nova variante, com a atualização dos protocolos de definição; e estudos sobre a eficácia das vacinas disponíveis no Brasil na vigência da nova variante. Propomos, ademais, o aprimoramento do sistema de vigilância em saúde brasileiro para que seja articulado com a vigilância genômica, de forma a responder mais oportunamente a emergências futuras. Chamamos os agentes públicos implicados na vigilância em saúde para que compartilhem dados e informações referentes à epidemia de forma clara, rápida e transparente. Finalmente propomos maior engajamento na cooperação interinstitucional de todos os envolvidos na resposta e produção de conhecimento sobre a pandemia em nosso país.

Coevolutionary patterns caused by prey selection.

Many theoretical models have been formulated to better understand the coevolutionary patterns that emerge from antagonistic interactions. These models usually assume that the attacks by the exploiters are random, so the effect of victim selection by exploiters on coevolutionary patterns remains unexplored. Here we analytically studied the payoff for predators and prey under coevolution assuming that every individual predator can attack only a small number of prey any given time, considering two scenarios: (i) predation occurs at random; (ii) predators select prey according to phenotype matching. We also develop an individual based model to verify the robustness of our analytical prediction. We show that both scenarios result in well known similar coevolutionary patterns if population sizes are sufficiently high: symmetrical coevolutionary branching and symmetrical coevolutionary cycling (Red Queen dynamics). However, for small population sizes, prey selection can cause unexpected coevolutionary patterns. One is the breaking of symmetry of the coevolutionary pattern, where the phenotypes evolve towards one of two evolutionarily stable patterns. As population size increases, the phenotypes oscillate between these two values in a novel form of Red Queen dynamics, the episodic reversal between the two stable patterns. Thus, prey selection causes prey phenotypes to evolve towards more extreme values, which reduces the fitness of both predators and prey, increasing the likelihood of extinction.

Effect of gradual temperature increase on the carbohydrate energy metabolism responses of the Antarctic fish Notothenia rossii.

The warming of the Southern Ocean waters may affect the biological processes and the performance of the fish inhabiting it. The notothenioid group is metabolically specialized to low-temperature environments and may be vulnerable to the climatic changes imposed on the Antarctic continent. However, gradual temperature changes potentially allow an opportunity for plasticity adjustments. The present study evaluated the effect of gradual increase of temperature on the enzymatic and nonenzymatic parameters of energy metabolism in renal, branchial, hepatic, and encephalic tissue of Notothenia rossii subjected to a gradual temperature change of 0.5 °C/day until reaching 2 °C, 4 °C, 6 °C, and 8 °C. Under the effect of an acclimation rate of 0.5 °C/day, the gill tissue showed increased phosphofructokinase (PFK) enzyme activity. In the kidney, there was increased activity of the malate dehydrogenase (MDH), glucose-6-phosphatase (G6PDH), and glycogen phosphorylase (GP) enzymes. There was an increase in lactate concentration in the liver and an increase in GP enzyme activity in the brain. The specific tissue responses indicate the presence of thermal plasticity and an attempt to regulate energy metabolism to mitigate thermal stress in this species under these experimental conditions, possibly through the activation of glycolysis, gluconeogenesis, and glycogenolysis.

Defensive behavior associated with secretions from the prosternal paired glands of the larvae of Heliconius erato phyllis Fabricius (Lepidoptera, Nymphalidae)

Defensive behavior associated with secretions from the prosternal paired glands of the larvae of Heliconius erato phyllis Fabricius (Lepidoptera, Nymphalidae). Our work presents for the first time, the defensive behavior associated with the release of the product of the prosternal paired glands of the larva of Heliconius erato phyllis Fabricius, 1775 (Lepidoptera, Nymphalidae, Heliconiinae). The prosternal glands were first described for larvae of H. erato phyllis. They are formed by two types of glandular structures: the impair gland and the paired glands. The prosternal glands are located within the conical integumentary sac, which in turn is situated on the individual's prosternum. The main goal of this study is to analyze the existence of any secretion from the prosternal paired glands, and check the action mode of this secretion. The methodology used for chemical analysis of the glands included the aeration and, analysis in gas chromatography and gas chromatography-mass spectrometry. The results show that the prosternal glands do not produce volatiles. Bioassays were conducted with simulated and natural attacks and revealed that the prosternal paired glands produce secretions of defense together with silk produced by labials glands as a defense strategy, described for the first time, against ants. The strategy consists in wrapping the ant with silk threads, the entire wrapped object moved to the end of the body, with the aid of the legs and prolegs, and possibly fixed in a nearby place. Evidence for the existence of a conical integumentary sac in larvae of other species and families of Lepidoptera allows us to propose the possibility of occurrence of prosternal paired glands with defensive function in these other groups as well.