COVID-19 in Africa: preexisting immunity and HIV

Intersecting epidemics: COVID-19 and HIV in sub-Saharan Africa. A systematic review (2020-2022)

There has been significant progress with regards to winning the fight against HIV globally, particularly due to the introduction of antiretroviral therapy (ART). COVID-19 threatened to derail gains in the fight against HIV. As we have started to see with studies on COVID-19 and HIV, there is a need to 'provide an in-depth view' in understanding the dynamics between the two epidemics, especially in sub-Saharan Africa. We, therefore, undertook a systemic review of existing literature to synthesize the effects of COVID-19 on the utilization of HIV services in sub-Saharan Africa, the literature on the risks associated with HIV during the COVID-19 pandemic, and lastly, the innovations and strategies adopted to continue receiving treatment in sub-Saharan Africa. We conducted a systematic review of studies published between 2020 and April 2022. We searched for relevant sub-Saharan studies in the following databases: PubMed, Google Scholar, J-STOR, and Science Direct. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search identified 647 papers, and after screening, 41 were in line with the inclusion criteria and were included in the review. There was evidence of the negative effects of COVID-19 on reducing HIV testing, ART treatment, and HIV prevention services. There is evidence pointing to the need for people living with HIV to be prioritized for COVID-19 vaccinations. Innovations and strategies implemented to mitigate the effects of COVID-19 on HIV services include community-based ART distribution, multi-month ART dispensing, the use of digital technologies, and the use of the already existing HIV infrastructure to fight COVID-19. It is still imperative that future studies explore the predictors of utilization of HIV services in the advent of COVID-19.

Thirty-Day Outcomes of Young and Middle-Aged Adults Admitted with Severe COVID-19 in Uganda: A Retrospective Cohort Study

Background

There is scarcity of data regarding young and middle-aged adults hospitalized with severe Corona Virus Disease 2019 (COVID-19) in Africa. In this study, we describe the clinical characteristics and 30-day survival among adults aged 18 to 49 years admitted with severe COVID-19 in Uganda.

Methods

We reviewed treatment records of patients admitted with severe COVID-19 across five COVID-19 treatment units (CTU) in Uganda. We included individuals aged 18 to 49 years, who had a positive test or met the clinical criteria for COVID-19. We defined severe COVID-19 as having an oxygen saturation <94%, lung infiltrates >50% on imaging and presence of a co-morbidity that required admission in the CTU. Our main outcome was the 30-day survival from the time of admission. We used a Cox proportional hazards model to determine the factors associated with 30-day survival at a 5% level of significance.

Results

Of the 246 patient files reviewed, 50.8% (n = 125) were male, the mean ± (standard deviation) age was 39 ± 8 years, majority presented with cough, 85.8% (n = 211) and median C-reactive protein (interquartile range) was 48 (47.5, 178.8) mg/L. The 30-day mortality was 23.9% (59/246). At admission, anemia (hazard ratio (HR): 3.00, 95% confidence interval (CI), 1.32-6.82; p = 0.009) and altered mental state (GCS <15) (HR: 6.89, 95% CI: 1.48-32.08, p = 0.014) were significant predictors of 30-day mortality.

Conclusion

There was a high 30-day mortality among young and middle-aged adults with severe COVID-19 in Uganda. Early recognition and targeted management of anemia and altered consciousness are needed to improve clinical outcomes.

SARS-CoV-2 immunity and vaccine strategies in people with HIV

Current severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines, based on the ancestral Wuhan strain, were developed rapidly to meet the needs of a devastating global pandemic. People living with Human Immunodeficiency Virus (PLWH) have been designated as a priority group for SARS-CoV-2 vaccination in most regions and varying primary courses (two- or three-dose schedule) and additional boosters are recommended depending on current CD4+ T cell count and/or detectable HIV viraemia. From the current published data, licensed vaccines are safe for PLWH, and stimulate robust responses to vaccination in those well controlled on antiretroviral therapy and with high CD4+ T cell counts. Data on vaccine efficacy and immunogenicity remain, however, scarce in PLWH, especially in people with advanced disease. A greater concern is a potentially diminished immune response to the primary course and subsequent boosters, as well as an attenuated magnitude and durability of protective immune responses. A detailed understanding of the breadth and durability of humoral and T cell responses to vaccination, and the boosting effects of natural immunity to SARS-CoV-2, in more diverse populations of PLWH with a spectrum of HIV-related immunosuppression is therefore critical. This article summarizes focused studies of humoral and cellular responses to SARS-CoV-2 infection in PLWH and provides a comprehensive review of the emerging literature on SARS-CoV-2 vaccine responses. Emphasis is placed on the potential effect of HIV-related factors and presence of co-morbidities modulating responses to SARS-CoV-2 vaccination, and the remaining challenges informing the optimal vaccination strategy to elicit enduring responses against existing and emerging variants in PLWH.

The impact of COVID-19 on communicable and non-communicable diseases in Africa: a narrative review

The global pandemic of coronavirus disease 2019 (COVID-19) has disproportionately impacted global human health, economy, and security. Because of weaker health-care systems, existing comorbidities burden (HIV, malaria, tuberculosis, and non-communicable conditions), and poor socioeconomic determinants, initial predictive models had forecast a disastrous impact of COVID-19 in Africa in terms of transmission, severity, and deaths. Nonetheless, current epidemiological data seem not to have matched expectations, showing lower SARS-CoV-2 infection and fatality rates compared to Europe, the Americas and Asia. However, only few studies were conducted in low- and middle-income African settings where high poverty and limited access to health services worsen underlying health conditions, including endemic chronic infectious diseases such as HIV and tuberculosis. Furthermore, limited, and heterogeneous research was conducted to evaluate the indirect impact of the pandemic on general health services and on major diseases across African countries. International mitigation measures, such as resource reallocation, lockdowns, social restrictions, and fear from the population have had multi-sectoral impacts on various aspects of everyday life, that shaped the general health response. Despite the vast heterogeneity of data across African countries, available evidence suggests that the COVID-19 pandemic has severely impacted the control and prevention programs, the diagnosis capacity and the adherence to treatment of major infectious diseases (HIV, TB, and Malaria) - including neglected diseases - and non-communicable diseases. Future research and efforts are essential to deeply assess the medium- and long-term impact of the pandemic, and to implement tailored interventions to mitigate the standstill on decades of improvement on public health programs.

Cross-Reactive Antibodies to SARS-CoV-2 and MERS-CoV in Pre-COVID-19 Blood Samples from Sierra Leoneans

Many countries in sub-Saharan Africa have experienced lower COVID-19 caseloads and fewer deaths than countries in other regions worldwide. Under-reporting of cases and a younger population could partly account for these differences, but pre-existing immunity to coronaviruses is another potential factor. Blood samples from Sierra Leonean Lassa fever and Ebola survivors and their contacts collected before the first reported COVID-19 cases were assessed using enzyme-linked immunosorbent assays for the presence of antibodies binding to proteins of coronaviruses that infect humans. Results were compared to COVID-19 subjects and healthy blood donors from the United States. Prior to the pandemic, Sierra Leoneans had more frequent exposures than Americans to coronaviruses with epitopes that cross-react with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), SARS-CoV, and Middle Eastern respiratory syndrome coronavirus (MERS-CoV). The percentage of Sierra Leoneans with antibodies reacting to seasonal coronaviruses was also higher than for American blood donors. Serological responses to coronaviruses by Sierra Leoneans did not differ by age or sex. Approximately a quarter of Sierra Leonian pre-pandemic blood samples had neutralizing antibodies against SARS-CoV-2 pseudovirus, while about a third neutralized MERS-CoV pseudovirus. Prior exposures to coronaviruses that induce cross-protective immunity may contribute to reduced COVID-19 cases and deaths in Sierra Leone.