COVID-19 vaccine may need to be re-engineered for South Africa
National Institute for Communicable Diseases (NICD) acting executive director Professor Adrian Puren has noted that the recently-discovered coronavirus mutation may require the COVID-19 vaccine to be re-engineered to be effective.
The COVID-19 vaccine employs an antigen protein that is designed to train the immune system to produce antibodies that protect against the coronavirus.
However, if the “South African strain” of the coronavirus has mutated sufficiently, the antibodies created by this protein may not be entirely effective against it.
This may be a major problem, considering that this variant is most prevalent within the second wave of COVID-19 cases in South Africa.
The 501.V2 variant of COVID-19 that emerged in South Africa has undergone mutations which may affect antibody recognition and subsequently the vaccine, although this currently remains unclear.
“There are two mutations that have resulted in two amino acid changes in the receptor membrane binding protein that is key in antibody recognition,” Puren told MyBroadband.
“These changes, in theory, can affect antibody binding and it is currently under investigation to determine what effect if any these will have.”
“If this region is essential for antibody responses, then the antigen protein may have to be re-engineered to ensure efficacy,” he said.
Puren also noted that the NICD is investigating and monitoring re-infections.
At present there is no indication that this variant is associated with increased risk of re-infections, he said, although he noted this will be difficult to disentangle with the ongoing increased likelihood of re-infections as the epidemic progresses.
Prevalence in South Africa
Puren said that data on COVID-19 variants is still being sourced, but he noted the 501.V2 variant was the dominant one in the Eastern Cape, KwaZulu-Natal, and the Western Cape – hotspots defined at the beginning of South Africa’s second wave of COVID-19 infections.
“The lineage was initially in co-circulation with other lineages and then was noted to be the dominant lineage in three coastal provinces: Eastern Cape, KwaZulu Natal and the Western Cape,” Puren said.
“The lineage is associated with the resurgence that was initially observed in the Eastern Cape followed by Western Cape, KwaZulu Natal, and Gauteng.”
“However, with ongoing changes in restrictions, compliance with non-pharmaceutical interventions, super spreader events, end-of-year celebrations, and travel, it is difficult to disentangle multiple drivers of disease transmission,” he said.
He said that fewer than 1% of cases of COVID-19 in SA have linked genomic data, and this differs by time, province, and facility.
Sequencing was also not done systematically throughout the country across all the months COVID-19 has been present, which makes it difficult to determine exactly when this variant emerged.
“The emergence of the lineage will become clearer as data are gathered, both retrospectively and prospectively,” Puren said.
Symptoms and preventing transmission
Researchers from the United Kingdom have suggested the South African variant of the coronavirus appears to be more transmissible due to its higher viral load, although it is currently unclear whether the symptoms it causes are more or less severe than the original virus.
“Detecting increased severity is inevitably more delayed, as we await outcomes from cases to be reached, however no clear evidence of increased or decreased severity have been detected as we review our clinical surveillance systems,” Puren said.
“Differences by age and sex have not been detected yet, but we need to acknowledge that sampling has not been extensive or systematic enough to allow for these analyses.”
Puren stressed that despite the prevalence of coronavirus variants, the management of the virus and prevention of its transmission remains the same.
“The management of patients presenting with COVID-19 remains unchanged,” Puren said.
“Similarly, prevention of transmitting the virus remains essentially unchanged viz., reliance on physical distancing, wearing of masks, hand hygiene, and ventilation.”
“The reverting to level 3 is an effort at re-enforcing these non-pharmaceutical interventions,” he added.
He also stressed that there is no major concern that diagnostic testing will be affected by these changes.
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