All content matching "COVID-19"

COVID-19 articles

Technical and working papers that go in depth looking at research approaches, methods, findings and limitations available from the Global South AI4COVID program website.

Effectiveness of an inactivated Covid-19 vaccine with homologous and heterologous boosters against Omicron in Brazil

Abstract The effectiveness of inactivated vaccines (VE) against symptomatic and severe COVID-19 caused by omicron is unknown. We conducted a nationwide, test-negative, case-control study to estimate VE for homologous and heterologous (BNT162b2) booster doses in adults who received two doses of CoronaVac in Brazil in the Omicron context. Analyzing 1,386,544 matched-pairs, VE against symptomatic disease was 8.6% (95% CI, 5.6–11.5) and 56.8% (95% CI, 56.3–57.3) in the period 8–59 days after receiving a homologous and heterologous booster, respectively. During the same interval, VE against severe Covid-19 was 73.6% (95% CI, 63.9–80.7) and 86.0% (95% CI, 84.5–87.4) after receiving a homologous and heterologous booster, respectively. Waning against severe Covid-19 after 120 days was only observed after a homologous booster. Heterologous booster might be preferable to individuals with completed primary series inactivated vaccine.

Effectiveness of CoronaVac, ChAdOx1 nCoV-19, BNT162b2, and Ad26.COV2.S among individuals with previous SARS-CoV-2 infection in Brazil: a test-negative, case-control study

Using national COVID-19 notification, hospitalisation, and vaccination datasets from Brazil, we did a testnegative, case-control study to assess the effectiveness of four vaccines (CoronaVac [Sinovac], ChAdOx1 nCoV-19 [AstraZeneca], Ad26.COV2.S [Janssen], and BNT162b2 [Pfizer-BioNtech]) for individuals with laboratory-confirmed previous SARS-CoV-2 infection. We matched cases with RT-PCR positive, symptomatic COVID-19 with up to ten controls with negative RT-PCR tests who presented with symptomatic illnesses, restricting both groups to tests done at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity and the odds of hospitalisation or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines.

COVID-19, vaccine hesitancy and child vaccination: Challenges from Brazil

In the world, the governments' policy decisions in response to COVID-19 were very different. Many countries, including in the Americas, political polarisation in health policies has been used as a tool for ideological dispute, draining out the debate around the right to social protection and health. During 2021, these strategies were used in vaccination policies. The consequences of the dissemination of misinformation about COVID-19 vaccines overflows distrust and hesitation into an entire public health project.

PRE-PRINT: The effectiveness of Vaxzevria and CoronaVac vaccines: A nationwide longitudinal retrospective study of 61 million Brazilians (VigiVac-COVID19)

Both  vaccines  demonstrated  overall  effectiveness  against  severe  COVID-19  up  to  80  years  of age.  Our  results  suggest  that  individuals  aged  90  years or  older  may  benefit from  an expedited  third  booster  dose.  Ongoing  evaluations, including  any  additional  vaccines authorized,  are  crucial  to  monitoring  long-term vaccine  effectiveness.

PRE-PRINT: Effectiveness of the CoronaVac Vaccine in Prevention of Symptomatic and Progression to Severe COVID-19 in Pregnant Women in Brazil

A complete regimen of CoronaVac in pregnant women was effective in preventing symptomatic Covid-19, and highly effective against severe illness in a setting that combines high disease burden and elevated Covid-19 related maternal deaths.

Safeguarding people living in vulnerable conditions in the COVID-19 era through universal health coverage and social protection

The COVID-19 pandemic is unprecedented. The pandemic not only induced a public health crisis, but has led to severe economic, social, and educational crises. Across economies and societies, the distributional consequences of the pandemic have been uneven. Among groups living in vulnerable conditions, the pandemic substantially magnified the inequality gaps, with possible negative implications for these individuals' long-term physical, socioeconomic, and mental wellbeing. This Viewpoint proposes priority, programmatic, and policy recommendations that governments, resource partners, and relevant stakeholders should consider in formulating medium-term to long-term strategies for preventing the spread of COVID-19, addressing the virus's impacts, and decreasing health inequalities.

Younger Brazilians hit by COVID-19 – What are the implications?

By the first week of June, Brazil had reached almost 17 million cases and a little more than 472,000 deaths. A notable demographic change has been observed within this period, in which young and middle-aged adults representing an increasing share of patients in wards and intensive care units (ICU).

The impacts of climate change on homeless populations after the pandemic

The notion that health crises unfairly and disproportionately affect vulnerable populations was observed and documented during the greatest health crisis of this century. Furthermore, studies have shown that the distribution of COVID-19 is unequal among different ethnic and socioeconomic groups (Horta, 2020 and Wang, 2020). 

Predictability of COVID-19 worldwide lethality using permutation-information theory quantifiers

This paper examines the predictability of COVID-19 worldwide lethality considering 43 countries. Based on the values inherent to Permutation entropy (Hs) and Fisher information measure (Fs), we apply the Shannon-Fisher causality plane (SFCP), which allows us to quantify the disorder an evaluate randomness present in the time series of daily death cases related to COVID-19 in each country.

Effectiveness of COVID-19 vaccines against hospital admission with the Delta (B.1.617.2) variant

We recently reported vaccine effectiveness (VE) estimates against symptomatic disease with the Delta (B.1.617.2) variant.(1) After a full course, VE reached 88% with the Pfizer/BioNTech BNT162b2 vaccine and 67% with the AstraZeneca ChAdOx1 AZD1222 vaccine. This provided important evidence that despite modest reductions in protection, vaccines remain effective against Delta. However, the very recent emergence of the variant and the relatively low case numbers meant that it was not possible to estimate VE against severe disease.

Human endogenous retrovirus K activation in the lower respiratory tract of severe COVID-19 patients associates with early mortality.

Critically ill 2019 coronavirus disease patients (COVID-19) under invasive mechanical ventilation (IMV) are 10- to 40-times more likely to die than the general population. Although progression from mild to severe COVID-19 has been associated with hypoxia, uncontrolled inflammation and coagulopathy, the mechanisms involved in progression to severity are poorly understood. By analyzing the virome from tracheal aspirates (TA) of 25 COVID-19 patients under IMV, we found higher levels and differential expression of human endogenous retrovirus K (HERV-K) genes compared to nasopharyngeal swabs from mild cases and TA from non-COVID patients. Proteomic analysis and RT-PCR confirmed the presence of HERV-K in these patients.   

UK Public Health Rapid Support Team: Latest research & scientific insights

Long COVID: Implications for Clinical Development

Depression, Anxiety, and Lifestyle Among Essential Workers: A Web Survey From Brazil and Spain During the COVID-19 Pandemic

Essential workers have been shown to present a higher prevalence of positive screenings for anxiety and depression during the COVID-19 pandemic. Individuals from countries with socioeconomic inequalities may be at increased risk for mental health disorders.

Covid-19 Confinement and Changes of Adolescent’s Dietary Trends in Italy, Spain, Chile, Colombia and Brazil

Confinement due to the COVID-19 pandemic can influence dietary profiles, especially those of adolescents, who are highly susceptible to acquiring bad eating habits. Adolescents’ poor dietary habits increase their subsequent risk of degenerative diseases such as obesity, diabetes, cardiovascular pathologies, etc. Our aim was to study nutritional modifications during COVID-19 confinement in adolescents aged 10 to 19 years, compare them with their usual diet and dietary guidelines, and identify variables that may have influenced changes. 

COVID-19 Scientific and Public Health Policy Update

In addition to our Weekly Outbreak Brief on the spread of COVID-19 and the actions that Africa CDC is taking to help African Union Member States.

Medical PPE production in Africa: Promoting Local Manufacturers to support the COVID-19 Response (Workshop report)

The global pandemic has highlighted fragility in international supply chains and the dependency of many African countries on imported personal protective equipment (PPE). 

Questions and answers on COVID-19 vaccine

Vaccines work by tricking your body into thinking it has been infected with a disease-causing organism (also called germs) such as a virus, prompting it to develop an immune reaction to the organism itself.

A Comparison of Vaccine Efficacy Elements in Advanced Stage Clinical Trial Protocols

Evaluating the Burden-of-Disease Endpoint to Assess Vaccine Efficacy

COVID-19 Efficacy Endpoints in Interventional Trials: What Constitutes an Incident Clinical Disease Case and What Triggers Diagnostic Work-Up V2.0

CONSIDERATIONS FOR EVALUATION OF COVID19 VACCINES

Priority List of COVID-19 Adverse events of special interest: Quarterly update 1

Considerations for Inclusion of Risk Populations into COVID-19 Vaccine Efficacy Trials

Psycho-Neuroendocrine-Immune Interactions in COVID-19: Potential Impacts on Mental Health

Coronavirus disease 2019 (COVID-19) is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The impacts of the disease may be beyond the respiratory system, also affecting mental health. Several factors may be involved in the association between COVID-19 and psychiatric outcomes, such as fear inherent in the pandemic, adverse effects of treatments, as well as financial stress, and social isolation. 

Efficacy Endpoints in COVID-19 Vaccine Trials: SARS-CoV-2 Infection

Vaccine Efficacy Assessment for COVID-19

COVID-19 Efficacy Endpoints in Interventional Trials: What Constitutes an Incident Clinical Disease Case and What Triggers Diagnostic Work-Up

General Core Elements for Early Phase Clinical Trials of COVID-19 Vaccine Candidates: Aspects to Consider

Speed coronavirus vaccine testing by deliberately infecting volunteers? Not so fast, some scientists warn

Human Challenge Studies to Accelerate Coronavirus Vaccine Licensure

Consensus considerations on the assessment of the risk of disease enhancement with COVID-19 vaccines:

The SARS-CoV-2 pandemic presents an unprecedented challenge to global health with enormous health system, social and economic disruption and large numbers of deaths already experienced in many countries. Epidemiologic features confirm that ongoing spread to less affected areas is now a certainty.

Priority List of Adverse Events of Special Interest: COVID-19

To maximize the value of vaccine safety data in clinical trials given their relatively limited sample size, it is essential to standardize their collection, presentation and analysis when possible.Given serious adverse events following immunization (AEFIs) are fortuitously rare, this need for globally accepted standard case definitions that allow for valid comparisons extend to individual case reports, surveillance systems, and retrospective epidemiologic studies.

The global spread of 2019-nCoV: a molecular evolutionary analysis

The global spread of the 2019-nCoV is continuing and is fast moving, as indicated by the WHO raising the risk assessment to high. In this article, we provide a preliminary phylodynamic and phylogeographic analysis of this new virus. A Maximum Clade Credibility tree has been built using the 29 available whole genome sequences of 2019-nCoV and two whole genome sequences that are highly similar sequences from Bat SARS-like Coronavirus available in GeneBank.