Efficacy and effectiveness of COVID-19 vaccines in Africa: A systematic review.

BACKGROUND: Data on COVID-19 vaccine effectiveness to support regional vaccine policy and practice are limited in Africa. Thus, this review aimed to evaluate the efficacy and effectiveness of COVID-19 vaccines administered in Africa. METHODS: We systematically searched peer-reviewed randomized controlled trials (RCTs), prospective and retrospective cohort studies, and case-control studies that reported on VE in Africa. We carried out a risk of bias assessment, and the findings of this review were synthesized and presented in a narrative form, including tables and figures. The synthesis was focused on COVID-19 VE against various levels of the disease condition and outcomes (infection, hospitalization or critical, and death), time points, and variants of concern. RESULTS: A total of 13 studies, with a total sample size of 913,285 participants, were included in this review. The majority (8/13) of studies were from South Africa and 38.5% (5/13) were randomized clinical trials. The studies reported that a full dose of Pfizer-BioNTech vaccine had a VE of 100% against COVID-19 infection by Beta (B.1.351) and Delta variants and 96.7% against hospitalization by Delta variant. The Johnson and Johnson vaccine had VE ranging from 38.1%-62.0% against hospitalization and 51.9%- 86% against critical disease by Beta (B 1.351) variant. The Oxford-AstraZeneca vaccine had a VE of 89.4% against hospitalization by the Omicron variant but was not effective against the B.1.351 variant (10.4%). The Sinopharm vaccine had a VE of 67% against infection and 46% against hospitalization by Delta variant. CONCLUSIONS: COVID-19 vaccines administered in Africa were effective in preventing infections, hospitalization, and death. These review findings underscore the need for concerted efforts of all stakeholders to enhance the access and availability of COVID-19 vaccines and reinforce public awareness to reach the high-risk, unvaccinated group of the African population.

Urgent support mechanism: saving millions of COVID-19 vaccines from expiry in Africa.

Delivering COVID-19 vaccines with 4-6 weeks shelf life remains one of Africa's most pressing challenges. The Africa Centres for Disease Control and Prevention (Africa CDC) leadership recognised that COVID-19 vaccines donated to many African countries were at risk of expiry considering the short shelf life on delivery in the Member States and slow vaccine uptake rates. Thus, a streamlined rapid response system, the urgent support mechanism, was developed to assist countries accelerate COVID-19 vaccine uptake. We describe the achievements and lessons learnt during implementation of the urgent support mechanism in eight African countries. An Africa CDC team was rapidly deployed to meet with the Ministry of Health of each country alerted for COVID-19 vaccine expiry and identified national implementing partners to quickly develop operational work plans and strategies to scale up the urgent use of the vaccines. The time between the initiation of alerts to the start of the implementation was typically within 2 weeks. A total of approximately 2.5 million doses of vaccines, costing $900 000, were prevented from expiration. The urgent support has also contributed to the increased COVID-19 vaccination coverage in the Member States from 16.1% at the initiation to 25.3% at the end of the urgent support. Some of the effective strategies used by the urgent support mechanism included coordination between Africa CDC and country vaccine task forces, establishment of vaccination centres, building the capacity of routine and surge health workforce, procurement and distribution of vaccine ancillaries, staff training, advocacy and sensitisation events, and use of trusted religious scriptures and community influencers to support public health messages. The urgent support mechanism demonstrated a highly optimised process and serves as a successful example for acceleration and integration of vaccination into different healthcare delivery points.

Time to establish an international vaccine candidate pool for potential highly infectious respiratory disease: a community's view.

In counteracting highly infectious and disruptive respiratory diseases such as COVID-19, vaccination remains the primary and safest way to prevent disease, reduce the severity of illness, and save lives. Unfortunately, vaccination is often not the first intervention deployed for a new pandemic, as it takes time to develop and test vaccines, and confirmation of safety requires a period of observation after vaccination to detect potential late-onset vaccine-associated adverse events. In the meantime, nonpharmacologic public health interventions such as mask-wearing and social distancing can provide some degree of protection. As climate change, with its environmental impacts on pathogen evolution and international mobility continue to rise, highly infectious respiratory diseases will likely emerge more frequently and their impact is expected to be substantial. How quickly a safe and efficacious vaccine can be deployed against rising infectious respiratory diseases may be the most important challenge that humanity will face in the near future. While some organizations are engaged in addressing the World Health Organization's "blueprint for priority diseases", the lack of worldwide preparedness, and the uncertainty around universal vaccine availability, remain major concerns. We therefore propose the establishment of an international candidate vaccine pool repository for potential respiratory diseases, supported by multiple stakeholders and countries that contribute facilities, technologies, and other medical and financial resources. The types and categories of candidate vaccines can be determined based on information from previous pandemics and epidemics. Each participant country or region can focus on developing one or a few vaccine types or categories, together covering most if not all possible potential infectious diseases. The safety of these vaccines can be tested using animal models. Information for effective candidates that can be potentially applied to humans will then be shared across all participants. When a new pandemic arises, these pre-selected and tested vaccines can be quickly tested in RCTs for human populations.