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This article presents attitudes and practices regarding COVID-19 vaccination in the South American population. The study collected data from a self-administered survey distributed through social media platforms between February and April 2022 (N = 6555). The survey included questions related to participants' sociodemographic background, flu vaccination practices, sources of information about COVID-19, and opinions regarding pandemic management and vaccination against SARS-CoV-2. The respondents agreed with the statement that COVID-19 vaccines were necessary (86.4%), effective (79.8%), safe (79.1%), and should be mandatory (64%). Overall, 83.4% accepted vaccination and 12.3% refused it completely. Main rejection reasons were safety (65.8%) and efficacy (54.9%) issues, and rushed development and approvals (49.1%). Vaccine uptake was associated with being ≥60 years, being a healthcare worker, previous influenza vaccine uptake, adherence to preventive measures, the death of ≥1 close people from COVID-19, and being informed through mass media or health authorities' channels. Vaccine uptake inversely correlated with male gender, low educational level, and use of closed social networks for COVID-19 information purposes. This study provides valuable insights into COVID-19 vaccination attitudes and practices in South America that may be used to promote vaccine uptake in the region. Higher COVID-19 vaccination acceptance among people with previously acquired prevention habits reinforces the importance of routine health promotion strategies. [ABSTRACT FROM AUTHOR]

Studies of Plasmodium falciparum invasion pathways in field isolates have been limited. Red blood cell (RBC) invasion is a complex process involving two invasion protein families; Erythrocyte Binding-Like (EBL) and the Reticulocyte Binding-Like (PfRh) proteins, which are polymorphic and not fully characterized in field isolates. To determine the various P. falciparum invasion pathways used by parasite isolates from South America, we studied the invasion phenotypes in three regions: Colombia, Peru and Brazil. Additionally, polymorphisms in three members of the EBL (EBA-181, EBA-175 and EBL-1) and five members of the PfRh (PfRh1, PfRh2a, PfRh2b, PfRh4, PfRh5) families were determined. We found that most P. falciparum field isolates from Colombia and Peru invade RBCs through an atypical invasion pathway phenotypically characterized as resistant to all enzyme treatments (NrTrCr). Moreover, the invasion pathways and the ligand polymorphisms differed substantially among the Colombian and Brazilian isolates while the Peruvian isolates represent an amalgam of those present in the Colombian and Brazilian field isolates. The NrTrCr invasion profile was associated with the presence of the PfRh2a pepC variant, the PfRh5 variant 1 and EBA-181 RVNKN variant. The ebl and Pfrh expression levels in a field isolate displaying the NrTrCr profile also pointed to PfRh2a, PfRh5 and EBA-181 as being possibly the major players in this invasion pathway. Notably, our studies demonstrate the uniqueness of the Peruvian P. falciparum field isolates in terms of their invasion profiles and ligand polymorphisms, and present a unique opportunity for studying the ability of P. falciparum parasites to expand their invasion repertoire after being reintroduced to human populations. The present study is directly relevant to asexual blood stage vaccine design focused on invasion pathway proteins, suggesting that regional invasion variants and global geographical variation are likely to preclude a simple one size fits all type of vaccine. [ABSTRACT FROM AUTHOR]

The article examines whether vampire bat population control practices pose a threat to the endemic bat Lonchophylla dekeyseri of the Cerrado, considered the most extensive woodland-savanna in South America. The VORTEX program was used to model different vampire bat management scenarios, which cause mortality to the bat populations. Bats act as pollinators of native plants and as seed dispersers which help restore degraded areas. Findings revealed that management practices have serious impacts on the endemic bat. Decreases in survival probability and genetic diversity were observed, as well as declines resulting from interaction between bat management and inbreeding depression.

Ecological niche modeling (ENM) has become an important tool in conservation biology. Despite its recent success, several basic issues related to algorithm performance are still being debated. We assess the ability of two of the most popular algorithms, GARP and Maxent, to predict distributions when sampling is geographically biased. We use an extensive data set collected in the Brazilian Cerrado, a biodiversity hotspot in South America. We found that both algorithms give richness predictions that are very similar to other traditionally used richness estimators. Also, both algorithms correctly predicted the presence of most species collected during fieldwork, and failed to predict species collected only in very few cases (usually species with very few known localities, i.e.,\5). We also found that Maxent tends to be more sensitive to sampling bias than GARP. However, Maxent performs better when sampling is poor (e.g., low number of data points). Our results indicates that ENM, even when provided with limited and geographically biased localities, is a very useful technique to estimate richness and composition of unsampled areas. We conclude that data generated by ENM maximize the utility of existing biodiversity data, providing a very useful first evaluation. However, for reliable conservation decisions ENM data must be followed by well-designed field inventories, especially for the detection of restricted range, rare species. [ABSTRACT FROM AUTHOR]

The Plasmodium vivax Ookinete Surface Protein (Pvs25) is one of the leading malaria Transmission-Blocking Vaccine candidates based on its high immunogenicity in animal models, transmission-blocking activity of antibodies elicited in clinical trials and high conservation among P. vivax isolates from endemic areas. However, the polymorphism in gene encoding Pvs25 in endemic areas from South America has been poorly studied so far. Here, we investigated the genetic polymorphism of pvs25 in P. vivax isolates from five different regions of the Brazilian Amazon (Cruzeiro do Sul , Mâncio Lima , Guajará , Manaus and Oiapoque) and its impact on antigenicity of predicted B-cell epitopes using gene sequencing and epitope prediction tools. Firstly, only a non-synonymous substitution was found in the 657 bp amplified fragment in all sequenced samples, which represented an exchange of Gln by Lys at position 87 (Q87K) of protein amino acid sequence (domain II EGF-like). Q87K substitution was also present in all studied sites with a total frequency of 37.8%. Cruzeiro do Sul presented Q87K substitution in almost half of the isolates (48.4%), and an expressive frequency (40.5%) was also found in Manaus , while in Mâncio Lima , Guajará and Oiapoque , the frequencies were low (23.5%, 25% and 22.2% respectively). We also observed the Q87K mutation in a predicted B-cell epitope of pvs25, with no significant changes on its putative antigenicity. Our data suggest that the pvs25 gene is conserved among isolates from different Brazilian Amazon geographic regions, an important observation considering the antigen potentiality as a vaccine candidate to cover distinct P. vivax endemic areas worldwide. • Pvs25 gene sequence were identified in isolates from five different regions of Brazilian Amazon; • Pvs25 is extremely conserved in Brazilian Amazon field isolates presenting only one non-synonymous mutation; • Q87K mutation were found in 37,8% of our field isolates; • Although 17 non-synonymous mutations in sequences worldwide, there is no significant impact in predicted B-cell epitopes. [ABSTRACT FROM AUTHOR]