Leveraging HIV Program and Civil Society to Accelerate COVID-19 Vaccine Uptake, Zambia.

To accelerate COVID-19 vaccination delivery, Zambia integrated COVID-19 vaccination into HIV treatment centers and used World AIDS Day 2021 to launch a national vaccination campaign. This campaign was associated with significantly increased vaccinations, demonstrating that HIV programs can be leveraged to increase COVID-19 vaccine uptake.

Comparison of COVID-19 Pandemic Waves in 10 Countries in Southern Africa, 2020-2021.

We used publicly available data to describe epidemiology, genomic surveillance, and public health and social measures from the first 3 COVID-19 pandemic waves in southern Africa during April 6, 2020-September 19, 2021. South Africa detected regional waves on average 7.2 weeks before other countries. Average testing volume 244 tests/million/day) increased across waves and was highest in upper-middle-income countries. Across the 3 waves, average reported regional incidence increased (17.4, 51.9, 123.3 cases/1 million population/day), as did positivity of diagnostic tests (8.8%, 12.2%, 14.5%); mortality (0.3, 1.5, 2.7 deaths/1 million populaiton/day); and case-fatality ratios (1.9%, 2.1%, 2.5%). Beta variant (B.1.351) drove the second wave and Delta (B.1.617.2) the third. Stringent implementation of safety measures declined across waves. As of September 19, 2021, completed vaccination coverage remained low (8.1% of total population). Our findings highlight opportunities for strengthening surveillance, health systems, and access to realistically available therapeutics, and scaling up risk-based vaccination.

Clinical Characteristics and Outcomes of Patients Hospitalized With COVID-19 During the First 4 Waves in Zambia.

Importance: Few epidemiologic studies related to COVID-19 have emerged from countries in Africa, where demographic characteristics, epidemiology, and health system capacity differ from other parts of the world. Objectives: To describe the characteristics and outcomes of patients admitted to COVID-19 treatment centers, assess risk factors for in-hospital death, and explore how treatment center admissions were affected by COVID-19 waves in Zambia. Design, Setting, and Participants: This retrospective cohort study assessed patients admitted to COVID-19 treatment centers in 5 Zambian cities between March 1, 2020, and February 28, 2022. Exposures: Risk factors for in-hospital mortality, including patient age and severity of COVID-19, at treatment center admission. Main Outcomes and Measures: Patient information was collected, including inpatient disposition (discharged or died). Differences across and within COVID-19 waves were assessed. Mixed-effects logistic regression models were used to assess associations between risk factors and in-hospital mortality as well as between characteristics of admitted patients and timing of admission. Results: A total of 3876 patients were admitted during 4 COVID-19 waves (mean [SD] age, 50.6 [19.5] years; 2103 male [54.3%]). Compared with the first 3 waves (pooled), the proportion of patients who were 60 years or older admitted during wave 4, when the Omicron variant was circulating, was significantly lower (250 of 1009 [24.8%] vs 1116 of 2837 [39.3%]; P < .001). Factors associated with in-hospital mortality included older age (≥60 vs <30 years; adjusted odds ratio [aOR], 3.55; 95% CI, 2.34-5.52) and HIV infection (aOR, 1.39; 95% CI, 1.07-1.79). Within waves, patients who were admitted during weeks 5 to 9 had significantly higher odds of being 60 years or older (aOR, 2.09; 95% CI, 1.79-2.45) or having severe COVID-19 at admission (aOR, 2.49; 95% CI, 2.14-2.90) than those admitted during the first 4 weeks. Conclusions and Relevance: The characteristics of admitted patients during the Omicron wave and risk factors for in-hospital mortality in Zambia reflect data reported elsewhere. Within-wave analyses revealed a pattern in which it appeared that admission of higher-risk patients was prioritized during periods when there were surges in demand for health services during COVID-19 waves. These findings support the need to expand health system capacity and improve health system resiliency in Zambia and other countries with resource-limited health systems.

COVID-19 Vaccine Effectiveness Against Progression to In-Hospital Mortality in Zambia, 2021-2022.

Background: Coronavirus disease 2019 (COVID-19) vaccines are highly effective for reducing severe disease and mortality. However, vaccine effectiveness data are limited from Sub-Saharan Africa. We report COVID-19 vaccine effectiveness against progression to in-hospital mortality in Zambia. Methods: We conducted a retrospective cohort study among admitted patients at 8 COVID-19 treatment centers across Zambia during April 2021 through March 2022, when the Delta and Omicron variants were circulating. Patient demographic and clinical information including vaccination status and hospitalization outcome (discharged or died) were collected. Multivariable logistic regression was used to assess the odds of in-hospital mortality by vaccination status, adjusted for age, sex, number of comorbid conditions, disease severity, hospitalization month, and COVID-19 treatment center. Vaccine effectiveness of ≥1 vaccine dose was calculated from the adjusted odds ratio. Results: Among 1653 patients with data on their vaccination status and hospitalization outcome, 365 (22.1%) died. Overall, 236 (14.3%) patients had received ≥1 vaccine dose before hospital admission. Of the patients who had received ≥1 vaccine dose, 22 (9.3%) died compared with 343 (24.2%) among unvaccinated patients (P < .01). The median time since receipt of a first vaccine dose (interquartile range) was 52.5 (28-107) days. Vaccine effectiveness for progression to in-hospital mortality among hospitalized patients was 64.8% (95% CI, 42.3%-79.4%). Conclusions: Among patients admitted to COVID-19 treatment centers in Zambia, COVID-19 vaccination was associated with lower progression to in-hospital mortality. These data are consistent with evidence from other countries demonstrating the benefit of COVID-19 vaccination against severe complications. Vaccination is a critical tool for reducing the consequences of COVID-19 in Zambia.

COVID-19 Vaccine Effectiveness during a Prison Outbreak when Omicron was the Dominant Circulating Variant-Zambia, December 2021.

During a COVID-19 outbreak in a prison in Zambia from December 14 to 19, 2021, a case-control study was done to measure vaccine effectiveness (VE) against infection and symptomatic infection, when the Omicron variant was the dominant circulating variant. Among 382 participants, 74.1% were fully vaccinated, and the median time since full vaccination was 54 days. There were no hospitalizations or deaths. COVID-19 VE against any SARS-CoV-2 infection was 64.8%, and VE against symptomatic SARS-CoV-2 infection was 72.9%. COVID-19 vaccination helped protect incarcerated persons against SARS-CoV-2 infection during an outbreak while Omicron was the dominant variant in Zambia. These findings provide important local evidence that might be used to increase COVID-19 vaccination in Zambia and other countries in Africa.

Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Among Healthcare Workers-Zambia, July 2020.

BACKGROUND: Healthcare workers (HCWs) in Zambia have become infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). However, SARS-CoV-2 prevalence among HCWs is not known in Zambia. METHODS: We conducted a cross-sectional SARS-CoV-2 prevalence survey among Zambian HCWs in 20 health facilities in 6 districts in July 2020. Participants were tested for SARS-CoV-2 infection using polymerase chain reaction (PCR) and for SARS-CoV-2 antibodies using enzyme-linked immunosorbent assay (ELISA). Prevalence estimates and 95% confidence intervals (CIs), adjusted for health facility clustering, were calculated for each test separately, and a combined measure for those who had PCR and ELISA was performed. RESULTS: In total, 660 HCWs participated in the study, with 450 (68.2%) providing a nasopharyngeal swab for PCR and 575 (87.1%) providing a blood specimen for ELISA. Sixty-six percent of participants were females, and median age was 31.5 years (interquartile range, 26.2-39.8). The overall prevalence of the combined measure was 9.3% (95% CI, 3.8%-14.7%). PCR-positive prevalence of SARS-CoV-2 was 6.6% (95% CI, 2.0%-11.1%), and ELISA-positive prevalence was 2.2% (95% CI, .5%-3.9%). CONCLUSIONS: SARS-CoV-2 prevalence among HCWs was similar to a population-based estimate (10.6%) during a period of community transmission in Zambia. Public health measures such as establishing COVID-19 treatment centers before the first cases, screening for COVID-19 symptoms among patients who access health facilities, infection prevention and control trainings, and targeted distribution of personal protective equipment based on exposure risk might have prevented increased SARS-CoV-2 transmission among Zambian HCWs.

SARS-CoV-2 Prevalence among Outpatients during Community Transmission, Zambia, July 2020.

During the July 2020 first wave of severe acute respiratory syndrome coronavirus 2 in Zambia, PCR-measured prevalence was 13.4% among outpatients at health facilities, an absolute difference of 5.7% compared with prevalence among community members. This finding suggests that facility testing might be an effective strategy during high community transmission.

Prevalence of SARS-CoV-2 in six districts in Zambia in July, 2020: a cross-sectional cluster sample survey.

BACKGROUND: Between March and December, 2020, more than 20 000 laboratory-confirmed cases of SARS-CoV-2 infection were reported in Zambia. However, the number of SARS-CoV-2 infections is likely to be higher than the confirmed case counts because many infected people have mild or no symptoms, and limitations exist with regard to testing capacity and surveillance systems in Zambia. We aimed to estimate SARS-CoV-2 prevalence in six districts of Zambia in July, 2020, using a population-based household survey. METHODS: Between July 4 and July 27, 2020, we did a cross-sectional cluster-sample survey of households in six districts of Zambia. Within each district, 16 standardised enumeration areas were randomly selected as primary sampling units using probability proportional to size. 20 households from each standardised enumeration area were selected using simple random sampling. All members of selected households were eligible to participate. Consenting participants completed a questionnaire and were tested for SARS-CoV-2 infection using real-time PCR (rtPCR) and anti-SARS-CoV-2 antibodies using ELISA. Prevalence estimates, adjusted for the survey design, were calculated for each diagnostic test separately, and combined. We applied the prevalence estimates to census population projections for each district to derive the estimated number of SARS-CoV-2 infections. FINDINGS: Overall, 4258 people from 1866 households participated in the study. The median age of participants was 18·2 years (IQR 7·7-31·4) and 50·6% of participants were female. SARS-CoV-2 prevalence for the combined measure was 10·6% (95% CI 7·3-13·9). The rtPCR-positive prevalence was 7·6% (4·7-10·6) and ELISA-positive prevalence was 2·1% (1·1-3·1). An estimated 454 708 SARS-CoV-2 infections (95% CI 312 705-596 713) occurred in the six districts between March and July, 2020, compared with 4917 laboratory-confirmed cases reported in official statistics from the Zambia National Public Health Institute. INTERPRETATION: The estimated number of SARS-CoV-2 infections was much higher than the number of reported cases in six districts in Zambia. The high rtPCR-positive SARS-CoV-2 prevalence was consistent with observed community transmission during the study period. The low ELISA-positive SARS-CoV-2 prevalence might be associated with mitigation measures instituted after initial cases were reported in March, 2020. Zambia should monitor patterns of SARS-CoV-2 prevalence and promote measures that can reduce transmission. FUNDING: US Centers for Disease Control and Prevention.

Detection of B.1.351 SARS-CoV-2 Variant Strain - Zambia, December 2020.

The first laboratory-confirmed cases of coronavirus disease 2019 (COVID-19), the illness caused by SARS-CoV-2, in Zambia were detected in March 2020 (1). Beginning in July, the number of confirmed cases began to increase rapidly, first peaking during July-August, and then declining in September and October (Figure). After 3 months of relatively low case counts, COVID-19 cases began rapidly rising throughout the country in mid-December. On December 18, 2020, South Africa published the genome of a SARS-CoV-2 variant strain with several mutations that affect the spike protein (2). The variant included a mutation (N501Y) associated with increased transmissibility.†,§ SARS-CoV-2 lineages with this mutation have rapidly expanded geographically.¶,** The variant strain (PANGO [Phylogenetic Assignment of Named Global Outbreak] lineage B.1.351††) was first detected in the Eastern Cape Province of South Africa from specimens collected in early August, spread within South Africa, and appears to have displaced the majority of other SARS-CoV-2 lineages circulating in that country (2). As of January 10, 2021, eight countries had reported cases with the B.1.351 variant. In Zambia, the average number of daily confirmed COVID-19 cases increased 16-fold, from 44 cases during December 1-10 to 700 during January 1-10, after detection of the B.1.351 variant in specimens collected during December 16-23. Zambia is a southern African country that shares substantial commerce and tourism linkages with South Africa, which might have contributed to the transmission of the B.1.351 variant between the two countries.