An interesting comment published online in The Lancet Global Health July 9th considers this issue.
As of July 2021, at least four variants of concern are circulating globally in the SARS-CoV-2 pandemic that has resulted in nearly 180 million documented viral infections and almost 4 million COVID-19 deaths worldwide since December, 2019.
Variants of concern are lineages that have evolved from the ancestral RNA virus, with sufficient mutations to lead to substantial changes in viral characteristics, such as:
- Increased transmissibility
- Detrimental change in COVID-19 epidemiology
- Increased virulence
- Change in clinical presentation
- Decreased effectiveness of public health and social measures, available diagnostics, vaccines, or therapeutics.
In the Lancet Global Health, Waasila Jassat and colleagues describe the effect of a circulating variant first arrived in South Africa now known as Beta, with increased transmissibility and immune evasion.
The South African second COVID-19 surge coincided with the onset of the Beta variant, characterised by rapid spread, higher infection, admissions, and mortality rates than in the first wave.
The authors thereby drawing inferences in the differences in virulence of the ancestral and Beta variants.
These include evidence of greater morbidity and mortality seen with the Beta variant.
Although the authors suggest that the inference of greater virulence in the variant had several caveats.
Most notably the difficulty in differentiating true biological effects from the quality of care in a pressurised and overwhelmed health system.
This 13-month study of two waves driven by two different viral lineages is both interesting and instructive.
We can take several salient lessons away from the South African COVID-19 case study.
First is that hospital overcrowding at the height of the COVID-19 surge is an important cause of increased mortality.
Therefore, a crucial public health measure is to find ways to mitigate overcrowding through rapid expansion of hospital facilities or through a so called curve flattening strategy.
Expansion of hospital facilities is feasible, especially if this includes field, general and high care beds, rather than intensive care facilities, which require more constrained, specialised clinical and technical expertise.
Flattening the curve, on the other hand can prove more challenging.
How effective non-pharmaceutical measures have been in this regard, including tightly regulated lockdowns, remains controversial.
The combination of the aforementioned strategy might have reduced the effects of COVID-19 in the South African first wave by strict lockdowns. This includes an alcohol ban which might have reduced hospital demand and crowding especially in emergency and intensive care wards. This reduces the acuteness of the surge, which might have afforded health authorities sufficient time to expand and prepare.
The second lesson is that new variants are bad news, and every effort should be made to reduce the likelihood of these occurring.
Not only do new variants lead to reinfection with evasion of pre-existing immunities to prevent infection, but also immune mutations favour viral survival with traits such as enhanced transmissibility leading to a more rapid spread, more acute surges with inherent hospital planning, and subsequent increased mortality.
It is this effect which Jassat and colleagues described might have led to the increased mortality in the second wave.
After adjusting for, age, sex, race, comorbidities, health sector, province, and weekly admissions, there is still a residual increased mortality which they argue might be due to the virus itself.
Appropriate management of chronic conditions and comorbidities is essential during and between COVID-19 surges.
Chronic SARS-CoV-2 infection in patients with reduced immunity might be a key mechanism promoting the development of variants of concern.
Globally, we have witnessed reduced access and retention in care for patients with HIV, tuberculosis and non-communicable diseases such as diabetes and cancer in the past 18 months.
Strengthening of health systems to ensure continuing care for chronic conditions will be crucial to limit new variants of concern.
Finally, and perhaps the most important lesson, vaccination coverage in the COVID-19 pandemic is urgent.
The speed with which COVID-19 vaccines have been developed, tested, and reviewed for emergency use approval is both unprecedented and crucial as we contemplate potential ways to reach epidemic control.
Numerous vaccines are now available on the WHO line listing and show reasonable vaccine efficacy, even in the face of alternative viral strains to the ancestor.
Countries and cohort studies are beginning to report real world effectiveness data that would indicate not only benefits to the most clinically vulnerable individuals, but also reduction in transmission as a result of reduced community viral load secondary to vaccine coverage.
South Africa, and Africa at large has not yet had the same vaccine coverage as most of the rest of the world.
This is largely due to vaccine supply, global vaccine availability, and vaccine nationalism.
The consequences of this could play out as ongoing unchecked transmission of SARS-CoV-2 in Africa with ongoing replication and risk of new and potentially problematic variants of concern.
Thirty years ago, we face similar in inequity around the distribution of licence being antiretroviral agents to treat HIV.
The consequences then would be unnecessarily loss of young lives simply because of cost, availability and neglect.
In the few short months we have seen new SARS-CoV-2 variants of concern spread around the globe.
Inequitable distribution of COVID-19 vaccines will lead to much more global pandemic devastation. The time to act with conviction to vaccinate the whole world is now.
The London General Practice commends the government on its vaccination programme and encourages all those who are eligible to have COVID-19 vaccine to be vaccinated when appropriate.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed