Non-immune Individuals Research Articles

Dynamics of osteopontin levels and correlation with parasitemia in acute malaria in Uganda and Sweden

BackgroundMalaria remains a significant public health concern, especially for the deadliest parasite, Plasmodium falciparum. During acute malaria, various cytokines, including osteopontin (OPN), regulate the immune response. OPN has been shown to be protective against malaria in mice. Nonetheless, its precise function and potential ability to control parasites during acute malaria in humans remain poorly understood.ResultsBlood samples were collected from Swedish adults with imported malaria, Ugandan children and adults with symptomatic malaria (including follow-up after 42 days), Ugandans with non-malarial fever and healthy individuals from both Uganda and Sweden. Parasitemia was determined by microscopy. Malaria-negative samples were verified by LAMP. OPN and interferon-γ (IFN- γ) levels were measured using ELISA. In children, OPN levels were significantly higher during acute infection compared to levels after 42 days, whereas Ugandan adults showed no difference. Swedish adults with imported malaria had elevated OPN levels compared to both Swedish controls and Ugandan adults with malaria. Parasitemia was significantly correlated with both OPN and IFN-γ levels across the entire cohort. While a significant correlation between OPN and IFN-γ was evident overall, it remained statistically significant only in Ugandan adults when analyzed by subgroups. This suggests that OPN is not just a general marker of inflammation but may be regulated differently during the development of malaria immunity.ConclusionsIn acute malaria, elevated OPN levels showed a stronger correlation with lack of immunity than age. These findings underscore the potential importance of OPN in malaria, particularly in non-immune individuals.

Towards next-generation treatment options to combat Plasmodium falciparum malaria.

Malaria, which is caused by infection of red blood cells with Plasmodium parasites, can be fatal in non-immune individuals if left untreated. The recent approval of the pre-erythrocytic vaccines RTS, S/AS01 and R21/Matrix-M has ushered in hope of substantial reductions in mortality rates, especially when combined with other existing interventions. However, the efficacy of these vaccines is partial, and chemotherapy remains central to malaria treatment and control. For many antimalarial drugs, clinical efficacy has been compromised by the emergence of drug-resistant Plasmodium falciparum strains. Therefore, there is an urgent need for new antimalarial medicines to complement the existing first-line artemisinin-based combination therapies. In this Review, we discuss various opportunities to expand the present malaria treatment space, appraise the current antimalarial drug development pipeline and highlight examples of promising targets. We also discuss other approaches to circumvent antimalarial resistance and how potency against drug-resistant parasites could be retained.

Imported Malaria Cases and Fatality in East Africa: A Review

Malaria remains a critical public health challenge in East Africa, with endemic transmission in many regions. Recent trends, however, show an alarming rise in imported malaria cases—wherein individuals contract malaria in endemic areas and transport it to regions with lower or no endemicity. This review examines the epidemiology of imported malaria in East Africa, with a focus on contributing factors such as international travel, migration, and inadequate vector control. The fatality rates associated with imported malaria, often driven by delayed diagnosis, drug resistance, and limited healthcare resources, are explored in depth. The review highlights the risk factors for imported malaria, including the role of expatriates, tourists, refugees, and migrants in the cross-border transmission of malaria. In particular, non-immune individuals such as travelers are highly susceptible to severe disease, often leading to fatalities when treatment is delayed. In addition, the review discusses the complex transmission dynamics that arise from overlapping malaria transmission zones within East Africa, further complicating efforts to distinguish domestic from imported cases. Management strategies to combat imported malaria, including strengthening surveillance systems at entry points, enhancing diagnostic capabilities, and ensuring access to effective treatments, are outlined. The importance of cross-border collaboration between East African nations to harmonize malaria control strategies is emphasized. Additionally, the review identifies future research directions, including the need for more detailed epidemiological studies, ongoing drug resistance monitoring, and policy development to address the complexities of imported malaria. This comprehensive analysis underscores the significance of addressing imported malaria as a critical element in the broader fight against the disease, highlighting the need for tailored strategies to mitigate its impact on healthcare systems and prevent further transmission in East Africa. Keywords: Imported Malaria, Cases, Fatality, East Africa.

The effectiveness of nirsevimab in reducing the burden of disease due to respiratory syncytial virus (RSV) infection over time in the Madrid region (Spain): a prospective population-based cohort study.

Respiratory syncytial virus (RSV) infection is one of the main causes of morbidity and mortality from lower respiratory tract infections in children under 5 years of age worldwide. Given that, the objective of this study was estimate the effectiveness of nirsevimab (a single-dose, long-acting, human recombinant monoclonal antibody against RSV) over time for the prevention of respiratory episodes treated at different levels of care. A prospective and dynamic population-based cohort study was performed including infants born between April 1 and December 31, 2023, in the Madrid region who resided there during the follow-up period from October 1, 2023, to February 29, 2024. Infants were considered immunized from the day after receiving one dose (50 or 100 mg) of nirsevimab or nonimmunized individuals if they did not receive any dose. There were 4,100 episodes of primary care, 1,954 hospital emergencies, and 509 admissions, 82 of which required intensive care in the 33,859 participants analyzed. The adjusted effectiveness of nirsevimab in preventing hospitalization due to RSV infection was 93.6% (95% CI: 89.7 to 96.1) at 30 days and 87.6% (95% CI: 67.7 to 95.3) at 150 days. The number needed to treat to prevent one hospitalization were 314.19 (95% CI: 306.22 to 327.99) at 30 days and 24.30 (95% CI: 22.31 to 31.61) at 150 days. The adjusted effectiveness of nirsevimab in avoiding admission to an intensive care unit was 94.4% (95% CI: 87.3 to 97.5) at 30 days and 92.1% (95% CI: 64.0 to 98.3) at 90 days. The adjusted effectiveness of nirsevimab for avoiding primary care consultations and hospital emergency visits was lower. Immunization with nirsevimab is an effective measure for reducing the burden of care related to RSV at all levels of care albeit it decreases throughout follow-up. At 150 days it remained high for preventing hospital admissions. Other articles already published have also demonstrated high effectiveness although with preliminary results, short follow-up periods and wide confidence intervals. None have detected a decrease in effectiveness over time. These results can be quite useful in individual infant prevention and in the design of immunization campaigns.

Questionable Immunity to Mumps among Healthcare Workers in Italy-A Cross-Sectional Serological Study.

Highly contagious diseases, such as mumps, are a global concern as new epidemics continue to emerge, even in highly vaccinated populations. The risk of transmission and spread of these viruses is even higher for individuals who are more likely to be exposed, including healthcare workers (HCWs). In healthcare settings, both HCWs and patients are at risk of infection during the care process, potentially leading to nosocomial epidemic outbreaks. Mumps is often underestimated compared with measles and rubella, despite being milder and less likely to spread. In fact, the risk of complications following mumps infection is extremely high, especially if the disease occurs in adulthood. The measles-mumps-rubella (MMR) vaccine has been shown to be an excellent preventive measure. Unfortunately, the mumps component appears to be less effective in inducing immunity than those for measles and rubella (two-dose effectiveness of 85%, 95% and 97%, respectively). The main aim of our study was to investigate the prevalence of detectable mumps antibodies (serum IgG antibodies) in a cohort of Italian and foreign HCWs in relation to personal and occupational factors. We included in the study 468 subjects who underwent health surveillance at the Occupational Medicine Unit of the Tor Vergata Polyclinic in Rome during the period from January 2021 to March 2023. In our study, the proportion of HCWs found to be unprotected against mumps was very high (8.3%), and those found to be immune are below the WHO threshold for herd immunity (95%). From our data, it seems essential that all occupational health services carry out an accurate screening with a dose of anti-mumps antibodies to assess serological protection before starting a job, regardless of an individual's vaccination history. This approach is proving to be beneficial, accurate, as it allows all serologically non-immune individuals to be vaccinated in the workplace, including those who would be protected by their vaccination history but have lost the antibody response.

Results of screening for antibodies to varicella-zoster virus in healthcare workers of a multidisciplinary hospital in Moscow

Introduction. Given the unfavorable epidemic situation with chickenpox and shingles in Russia, there is a high risk of virus introduction and spread in healthcare settings, including among medical staff who are not immune to varicella zoster virus (VZV).
 The objective of this study is to assess the immunity of employees of a multidisciplinary hospital in Moscow to VZV.
 Materials and methods. A selective screening study was carried out. Venous blood serum samples were taken from 1546 hospital employees as material for detection of IgG antibodies to VZV antigens using a commercial solid-phase enzyme immunoassay (ELISA) test system "Vecto VZV-IgG". All employees were questioned to obtain information about their infectious and vaccine history in relation to VZV.
 Results and discussion. Screening for antibodies to VZV in the hospital workers revealed that 6.3% of those workers are not immune to VZV. The proportion of seronegative individuals was the highest (12.6 ± 2.4%) in the age group of 29 years and younger. VZV seronegative healthcare workers were found in various departments, but the presence of non-immune individuals among the staff of the obstetrics and gynecology departments (6.5%) is of epidemiologic concern. The results of the survey showed that documented data on infection and vaccination history cannot be used to assess the protection of healthcare workers against VZV infection.
 Conclusion. The results of serologic screening for antibodies to VZV made it possible to identify a significant number of susceptible employees of the multidisciplinary hospital. In order to prevent the formation of multiple epidemic foci of varicella in medical organizations, it is advisable to include anti-VZV testing of medical staff in the state prevention programs with subsequent vaccination of non-immune individuals.

Polio: Background and perspective on how international travel can be made safe against polio.

International spread of polio continues to be a Public Health Emergency of International Concern since its declaration by the World Health Organization in 2014 and its reiteration in 2024. In 2023 and 2024, two countries remained endemic for wild poliovirus (WPV) but 20 countries reported polio outbreaks due to vaccine-derived polioviruses (VDPVs) in 2023 and 10 countries in 2024 (up to mid-June). Guidelines from various agencies recommend polio vaccination before travelling to or from polio-affected countries, or attending mass gatherings anywhere in the world, particularly if the crowd is international. Immunity protects against polio paralysis but not against poliovirus re-infection, irrespective of which vaccine was involved - live attenuated oral polio vaccine (OPV) or inactivated poliovirus vaccine (IPV). Infection with WPV or circulating VDPV in the vast majority of non-immune individuals (first infection) is asymptomatic, while they are efficient virus transmitters. Re-infections in immune individuals are always asymptomatic, but they are also infectious and may act as source for further transmission, although less efficiently than the former. Thus, travellers can become transmission vectors, illustrated by many episodes of importations of WPV or VDPVs into polio-free countries in recent years. The route of poliovirus transmission remains controversial, with many believing it to be faecal-oral, but epidemiological analysis is consistent with respiratory route and not faecal-oral. Transmission occurs person-to-person during social contact. Travellers must ensure they are adequately immunised to avoid polio, and becoming vectors of virus importation. The vaccine efficacy (VE) of OPV is highly variable - high in temperate climate countries, particularly rich countries, but low or very low in tropical low-income countries. On the other hand, VE of IPV is excellent everywhere irrespective of geography.

Results of assessing herd immunity to SARS-CoV-2 in medical workers

article presents the results of a study of the level of antibodies to SARSCoV- 2 in the blood of 54 medical workers: those who were ill or vaccinated within six months before the start of the study (70.4 %), non-ill and unvaccinated (20.7 %), and those with hybrid immunit y (recovered from the disease and vaccinated) (6.9 %). The data obtained indicate a decrease in the level of herd immunity within six months, which is especially pronounced in non-immunized individuals. The presence of antibodies in low titers in non-ill and non-immunized individuals may indicate natural immunization in the context of the infection pandemic, which decreases sharply as the epidemic subsides.

Vaccine-preventable diseases: evaluating immune response in a sample of Italian healthcare students

Abstract Background Healthcare university students are exposed to a range of risk factors during their hospital practical training, particularly in relation to biological hazards. Despite being students, they must be paid the same attention as health professionals in relation to the same possibility of transmitting infections to fellow colleagues, patients, and the wider community.The primary aim of this study is to investigate the seroprevalence characteristics of IgG antibodies against main infectious diseases in students enrolled in medical and health-related degree programs in an Italian university. Methods We conducted a retrospective epidemiological study of health professions students of a university hospital in Rome, collecting sociodemographic information and serology of antibody titers under study (hepatitis B, measles, mumps, rubella and varicella) from 2013 to 2023. After initial description of the study population, bivariate and multivariate analyses were performed to study the association between presence of antibodies with relevant variables. Results Our study sample included 2523 students (68.5% females; mean age 22.2, SD 3.8), of which 44.4% were protected against HBV, 87.3% against measles, 85.5% against mumps, 94.6% rubella and 95.2% against varicella. Differences in antibody coverage between age groups were statistically significant (p < 0.001), with the exception of mumps. Surprisingly, the prevalence of HBV antibody titer below the seropositivity cut-off appeared to have an inverse correlation with older age (1998-99 OR 0.75 CI 0.61-0.93, 2000-01 OR 0.50 CI 0.41-0.62, 2002-04 OR 0.40 CI 0.31-0.52). Conclusions Despite several recommendations and campaigns to promote vaccinations, the goal of achieving high immunization rates among healthcare workers still represents a challenge. Public health policies should focus on improving prevention strategies, including serological screening and workplace vaccination for non-immune individuals, especially for Hepatitis B. Key messages • Improving prevention strategies, including serological screening and vaccination, is crucial to achieve high immunization rates among healthcare students, especially for Hepatitis B. • Health profession students are at risk of exposure to infectious diseases during hospital practical training, and the prevalence of immunity varies among different age groups.

A Study on Prevalence and Molecular Characterization of Spike Protein of SARS-COV2 in Pakistan

Objective: To examine the prevalence of antibody IgG/IgM and designing follow-up study of six months and to perform the molecular characterization and sequence analysis of spike protein of SARS-CoV-2.Study Design: Prevalence study. Place and Duration of the Study: The study was conducted in the Post-Graduate Lab of the National University of Medical Sciences (NUMS) Rawalpindi, Pakistan from January 2021 to June 2021.Methods: 112 suspected patients with mild and severe symptoms were tested by PCR (polymerase chain reaction) and all were positive. Antibody profiling of vaccinated and non-vaccinated patients was performed by enzyme-linked immunosorbent assay (ELISA) and followed up for up to six months.Results: Ten patients were identified as re-infected and were subsequently re-tested via PCR and DNA sequencing. The IgG/IgM of immunized patients was 11.87IU/mL and 3.87IU/mL in non-immunized individuals. Genomic analysis indicated that all the sequences belong to delta variant (21A and 21J sub-lineages). Mutations were observed in spike protein at I1169V, D950N in 21A and T951I and S254F in 21J sub-lineages.Conclusion: This study revealed the significance of measuring antibody levels among vaccinated and unvaccinated individuals. Additionally, mutations in the spike gene of the delta variant of SARS-CoV2 can influence the pathogen's mutation rate, leading to changes in its transmissibility and pathogenicity.
 How to cite this: Rizwan M, Ahad A, Aziz S, Lone NA, Naz T, Khan MB, Jafri L, Ali L. A Study on Prevalence and Molecular Characterization of Spike Protein of SARS-COV-2 in Pakistan. Life and Science. 2023; 4(4): 458-468. doi: http://doi.org/10.37185/LnS.1.1.400

Eliminating hepatitis B vaccination disparities for West African immigrants

BackgroundHepatitis B virus (HBV) infection is endemic in West Africa. There has been a significant increase in the Bronx West African (WA) community. To achieve HBV elimination, vaccination of non-immune individuals is important. Unfortunately, vaccine uptake in immigrant populations is at this time very limited. MethodsAn educational program was conducted by medical providers of WA origin in collaboration with local faith-based organizations, after which free HBV screening was offered. Non-immune individuals were initially recommended to contact their medical provider or referred to the Department of Health for vaccination. Beginning in 2021, the program offered vaccination. A questionnaire including reasons for vaccination in the program was offered. FindingsAmong the first500 individuals screened,34.6 % required vaccination. Among those screened before program vaccine availability, 72.2 % initiated the vaccination series,with38.2 % obtainingit at an outside setting and34 % returning when available through the program.Among patients screened after program vaccineavailability, 92.1 % initiated the series.Of those receiving vaccination in the program and completing the questionnaire,70.7 % had access to care but chose vaccination by the program because of the trust instilled by WA personnel. InterpretationOur findings demonstrate the effectiveness of integrating vaccination into an HBV screening program for an immigrant population. It emphasizes the importance of timeliness and cultural sensitivity.

Modeling Poliovirus Transmission and Responses in New York State.

In July 2022, New York State (NYS) reported a case of paralytic polio in an unvaccinated young adult, and subsequent wastewater surveillance confirmed sustained local transmission of type 2 vaccine-derived poliovirus (VDPV2) in NYS with genetic linkage to the paralyzed patient. We adapted an established poliovirus transmission and oral poliovirus vaccine evolution model to characterize dynamics of poliovirus transmission in NYS, including consideration of the immunization activities performed as part of the declared state of emergency. Despite sustained transmission of imported VDPV2 in NYS involving potentially thousands of individuals (depending on seasonality, population structure, and mixing assumptions) in 2022, the expected number of additional paralytic cases in years 2023 and beyond is small (less than 0.5). However, continued transmission and/or reintroduction of poliovirus into NYS and other populations remains a possible risk in communities that do not achieve and maintain high immunization coverage. In countries such as the United States that use only inactivated poliovirus vaccine, even with high average immunization coverage, imported polioviruses may circulate and pose a small but nonzero risk of causing paralysis in nonimmune individuals.

Early appearance of functional plasma cells (CD138+CD98+) in non-immunized neonate mice

Plasma cells (PCs) are terminally differentiated antibody-secreting cells, derived from activated B-lymphocytes in response to either T-independent or T-dependent antigens. The plasma cell population is scarce in circulation in non-immunized individuals. It is established that neonates are incapable of mounting an efficient immune response due to the immaturity of the immune system. However, this disadvantage is well overcome through the antibodies neonates receive from breastmilk. This implies that neonates will be only protected against antigens the mother had previously encountered. Thus, the child might be potentially susceptible to new antigens. This issue prompted us to seek for the presence of PCs in non-immunized neonate mice. We found a PC population identified as CD138+/CD98+ cells since day one after birth. These PCs were positive for Ki67 and expressed Blimp-1, B220, and CD19, which suggests the populations are plasmablasts and PCs with heterogeneous phenotype. These PCs were also determined to secrete antibodies, although mainly isotype IgM. Altogether, the results indicated that neonate PCs can produce antibodies against antigens they encounter in the first weeks of life, most likely coming from food, colonizing microbiota, or the environment.

Impact of vaccination against the novel coronavirus infection (COVID-19) with Sputnik V on mortality during the delta variant surge

ObjectivesThe aim is to study impact of vaccination against the novel coronavirus disease (COVID-19) with Sputnik V on mortality during the period of predominance of the delta variant of SARS-CoV-2. MethodsThis was a retrospective cohort study of individuals with state health insurance at the Moscow Ambulatory Center. The cohorts included 41,444 persons vaccinated with Sputnik V, 15,566 survivors of COVID-19, and 71,377 non-immune persons. The deaths of patients that occurred from June 1, 2021, to August 31, 2021, were analyzed. ResultsOverall (0.39 % vs. 1.92 %; p < 0.001), COVID-19-related (0.06 % vs. 0.83 %; p < 0.001), and non-COVID mortality (0.33 % vs. 1.09 %; p < 0.001) was lower among vaccinated individuals than among non-immune individuals. The efficacy of vaccination against death from COVID-19 was 96 % [95 % CI 91–98 %] in the general population, 100 % among those aged 18–50 years, 97 % [95 % CI 76–100 %] among those aged 51–70 years, 98 % [95 % CI 90–100 %] among those aged 71–85 years, and 88 % [95 % CI 49–97 %] among those aged > 85 years. ConclusionCOVID-19 vaccination with Sputnik V is associated with a decrease in overall and COVID-19-related mortality and is not with increased non-COVID mortality.

Estimating the risk reduction of isolation on COVID-19 nonhousehold transmission and severe/critical illness in nonimmune individuals: September to November 2021.

There is growing scientific interest in immunity mandates/passports (IMP) for viral diseases in light of the severe acute respiratory syndromecoronavirus 2 (SARS-CoV-2) pandemic. IMP isolate those who remain nonimmune from various settings to reduce nonhousehold transmissions from the nonimmune and reduce severe/critical illness among the nonimmune. A major limitation in the scientific literature is that there are currently no methods to quantify how many nonimmune individuals need to be isolated to achieve these purported benefits. This paper develops a procedure for estimating the benefits of IMP using a novel variant of the number needed to treat which we call the number needed to isolate (NNI). We use data from the SARS-CoV-2 pandemic to demonstrate the properties and utility of the NNI and to inform the debate about IMP. We focus on data from the European Union, United Kingdom, United States, Canada, Australia, and Israel during the fall 2021 when the Delta (B.1.617.2) variant predominated.

Procalcitonin (PCT) Improves the Accuracy and Sensitivity of CURB-65 Score in Predicting CAP Patients Admission to ICU

The CURB-65 scoring system is a simple tool for assessment and prognosis prediction for community-acquired pneumonia (CAP) patients. However, the variations in the performance of CURB-65 in young and elderly patients, underestimation, or overestimation of the severity have often been reported. It is worth noting that the application of biomarkers is helpful for improving the accuracy of the scoring system. In recent years, more and more reports and studies paid attention to procalcitonin (PCT) in respiratory infectious diseases, and its clinical value has attracted increasing attention. The study aimed at investigating the effectiveness of the CURB-65 score combined with PCT in predicting admission of CAP patients to intensive care units (ICU). We conducted a retrospective study. We analyzed data from 520 non-immune individuals over the age of 18 in this study. All patients received blood indicators measurement and CURB-65 score calculation on admission. The primary outcome used to assess the probability of a CAP patient was who would get a bed in general ward or ICU. Receiver operating characteristic curves (ROC) were used to evaluate the sensitivity and specificity of the CURB-65 model and PCT combined CURB-65 augmented model in predicting the main outcomes. After analyzing the data from 520 patients, we found that the probability of entering the ICU was 22.1% (115/520). The AUC of Combination 1 (PCT&CURB-65 scores), Combination 2 (WBC&CURB-65 scores), Combination 3 (hs-CRP&CURB-65 scores) and Combination 4 (D-dimer&CURB-65 scores) for predicting CAP patients entering the ICU was 0.92 (95% CI 0.88 - 0.95), 0.91 (95% CI 0.87 - 0.94), 0.89 (95% CI 0.85 - 0.92), and 0.90 (95% CI 0.87 - 0.94), respectively, with statistically significant differences (p = 0.00); the sensitivities were 0.83, 0.82, 0.77 and 0.77, respectively, and the specificities were 0.92, 0.84, 0.90 and 0.91, respectively. PCT was superior to other indexes to improve the sensitivity and specificity of the CURB-65 score. Procalcitonin improves the accuracy and sensitivity of the CURB-65 score in predicting the probability of CAP patients entering the ICU, and PCT was superior to other indexes to improve the sensitivity and specificity of the CURB-65 score.

The potency of plant antimalarial

Malaria has remained a major cause of morbidity and mortality in all parts of the world. It is associated with high economic burden on the nation, high prevalence of mortality in children, pregnant women and non-immune individuals, thus malaria is a global public health problem. This protozoan infection is mainly characterized by fever, pains, loss of appetite and anaemia, researchers had discovered potent antimalarial drugs mainly from plant sources in order to overcome resistance of antimalarials, vectors, inability to develop malarial vaccines and also toxic effects of conventional antimalarial drugs. Antimalarials obtained from plants have significant roles in drug discovery and development for the treatment of fever, pains, inflammation as well as Plasmodium falciparum infection, therefore this review focuses on the analgesics, antipyretics and anti-inflammatory activities as well as antiplasmodial activities of plants.

Comparison of Disease Severity and In-hospital Outcome of COVID-19 among Non-vaccinated versus Vaccinated (1st dose) Hospitalized Patients in a Tertiary Care Hospital: an Observational Study

Background: COVID-19 vaccines have a high rate of success in averting hospitalization and mortality. However, COVID-19 infection is still being detected among immunized patients, although with blunted severity. This study aimed to compare the severity and outcome of COVID-19 among immunized versus non-immunized individuals. Methods: This cross-sectional study was conducted over 179 COVID-19 patients in Popular Medical College Hospital, Dhaka. All the methods in the present study were carried out following the ethical guidelines of the 1975 Declaration of Helsinki. Data were collected from both hospital record and direct interview. Data were recorded in separated case record form and analyzed by STATA version 14. Results: Mean age of the study patients was 55.42±14.20 (SD) years wherein maximum were male (61.5%). Fever (88.8%), cough (81.6%), dyspnea (47.5%) and sore throat (30.2%) were most common symptoms. Maximum patients werehypertensive (60.9%) and diabetic (58.7%). About 35.8% of patients had mild severity, while 27.9% had moderate, 23.4% had severe, and 12.8% had critical stage. Maximum patients (n=122, 68.2%) were nonvaccinated and rest (n=57, 31.8%) had received 1st dose of vaccine. Vaccinated patients had significantly higher frequency of having mild COVID-19 (57.9% vs 31.1%, p&lt;0.001) and getting discharge with full recovery (94.7% vs 76.2%, p=0.003) compared to non-vaccinated patients. Moreover, non-vaccinated patients were more prone to develop critical clinical syndrome (10.6% vs 1.8%, p=0.039) and had died or referred to higher center (11.4% vs 1.8%, p=0.029) than vaccinated individuals. Conclusion: COVID-19 vaccination was significantly associated with mild severity and lower rate of adverse outcome. Bangladesh J Medicine 2022; 33: 293-299

Monkeypox Virus Outbreaks and Poxvirus Infections: Transmission Routes and Epidemiological Characteristics

While the eradication of smallpox virus, which is a success story achieved through a common struggle in human history, eliminated a major threat, the most important advantage was that the agent (variola virus) was not of zoonotic origin. The absence of smallpox infections around the world and the termination of extensive vaccination programs have led to a decrease in global orthopoxvirus immunity day by day. The increasing number of non-immune (for poxviruses) individuals and immunocompromised (general) patients around the world brings along new risks. The predictions that monkeypox virus (MPXV), which is known to cause milder infections in humans compared to smallpox, is seen as one of the 10 infectious agents with pandemic potential, and its spread area may expand, became a reality with the virus placed on the world agenda with the last epidemic in 2022. The approval of newly developed antiviral drugs and vaccines in the last few years shows that some countries are preparing for this change. Although it has been declared by the health authorities that MPXV infections have a low rate of spread among humans and that there is no risk of a new pandemic, the fact that changes in the transmission and spread pattern of the infection carried the virus out of the African continent indicates that new endemic areas may be occur outside the continent, via transmission of the virus from domestic animals to potential reservoir animals in the wild life, continues to be a cause for concern. The spreading possibility of MPXV infections by long transmission chains in immunocompromised populations is considered as another important risk. The risk of increasing cases turning into a growing epidemic and potential biosecurity threats have also raised concerns about the production, storage, and accessibility of preventive vaccines and antiviral drugs to be used in treatment. Considering the unusual rate of human-to-human transmission observed in the recent MPXV outbreak, the spreading of the virus to multiple countries unrelated to endemic areas, and other public health risks; the importance of monitoring MPXV and other poxvirus-related human and animal infections, informing the population at risk and health care workers, and other preventive activities is clearly apparent.

Antibody response to a new member of the DBL family (EBP2) after a brief Plasmodium vivax exposure.

Plasmodium vivax blood-stage invasion into reticulocyte is critical for parasite development. Thus, validation of novel parasite invasion ligands is essential for malaria vaccine development. Recently, we demonstrated that EBP2, a Duffy binding protein (DBP) paralog, is antigenically distinct from DBP and could not be functionally inhibited by anti-DBP antibodies. Here, we took advantage of a small outbreak of P.vivax malaria, located in a non-malarious area of Brazil, to investigate for the first time IgM/IgG antibodies against EBP2 and DEKnull-2 (an engineering DBPII vaccine) among individuals who had their first and brief exposure to P.vivax (16 cases and 22 non-cases). Our experimental approach included 4 cross sectional surveys at 3-month interval (12-month follow-up). The results demonstrated that while a brief initial P.vivax infection was not efficient to induce IgM/ IgG antibodies to either EBP2 or DEKnull-2, IgG antibodies against DEKnull-2 (but not EBP2) were boosted by recurrent blood-stage infections following treatment. Of interest, in most recurrent P. vivax infections (4 out of 6 patients) DEKnull-2 IgG antibodies were sustained for 6 to 12 months. Polymorphisms in the ebp2 gene does not seem to explain EBP2 low immunogenicity as the ebp2 allele associated with the P.vivax outbreak presented high identity to the original EBP2 isolate used as recombinant protein. Although EBP2 antibodies were barely detectable after a primary episode of P.vivax infection, EBP2 was highly recognized by serum IgG from long-term malaria-exposed Amazonians (range from 35 to 92% according to previous malaria episodes). Taken together, the results showed that individuals with a single and brief exposure to P.vivax infection develop very low anti-EBP2 antibodies, which tend to increase after long-term malaria exposure. Finally, the findings highlighted the potential of DEKnull-2 as a vaccine candidate, as in non-immune individuals anti-DEKnull-2 IgG antibodies were boosted even after a brief exposure to P.vivax blood stages.