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01 February 2021 | Story Prof Felicity Burt, Prof Dominique Goedhals & Dr Sabeehah Vawda | Photo istock

Opinion article by Prof Felicity Burt, Prof Dominique Goedhals, and Dr Sabeehah Vawda, Division of Virology, Faculty of Health Sciences, University of the Free State and National Health Laboratory Service, Bloemfontein. 

As we optimistically embarked on a new year with hopes of seeing an end to the global pandemic, masks, and social restrictions, our news channels were consumed with stories about virus variants and vaccine roll-out. What do these variants mean and will the vaccines protect against the changes that have emerged in the virus and save us from the new normal?

The news of a ‘mutated’ virus most likely conjures movie-like images of an invisible, indestructible enemy causing massive disruption. The reality is fortunately much less dramatic, as these changes are actually expected. Just to reiterate, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has an RNA genome that codes for all the proteins which the virus produces. The exact details of how the virus replicates and produces new progeny, although of interest, are beyond the scope of this article. It is sufficient at this point to merely acknowledge that, during replication, the mechanism employed by viruses with an RNA genome allows for the introduction of mutations in the genes that code for the viral proteins. This is expected to occur and there is substantial evidence that the SARS-CoV-2 viral genes have evolved and adapted globally. Some mutations are silent, in other words, they do not change the viral proteins. However, in some instances the changes can affect the proteins encoded by the virus. If these changes occur in regions of the protein responsible for binding to the cell receptors that facilitate entry of the virus into the cell, or in regions of the protein that induce an immune response, the virus may show new characteristics, such as more successful transmission or escape from an existing immune response. 

Second wave of infections

South Africa and the United Kingdom are probably the two countries globally that have methodically sequenced the largest number of SARS-CoV-2 viruses isolated from patients. This technique allows the determination of the complete genome of each isolate and subsequent comparison, using bioinformatic software specifically designed to compare and identify changes and mutations in the nucleotide sequences. As we are all now aware, scientists in these two countries have identified virus variants with an accumulation of mutations and deletions occurring in the gene that encodes for the viral spike protein associated with binding to cell receptors and inducing protective immune responses. These variants have now become the predominant lineages circulating within local communities. 

In December 2020, scientists in South Africa revealed the presence of a variant of concern (VOC), now referred to as 501Y.V2. Sequence data confirmed that this variant initially emerged in October 2020, and by January 2021 it was present in multiple provinces in the country and is considered to be responsible for a significant number of cases occurring in the second wave of infections in the country. A second VOC reported by scientists in the United Kingdom in December 2020, (202012/01) likely emerged during September 2020. A third VOC has been reported from Brazil and is simply known as variant P1. To date, variant 501Y.V2 has been reported from at least 23 countries. VOC 202012/01 has been reported in at least 60 countries, and although the cases were initially associated with travellers, there is an increasing number of clusters of cases occurring in people with no history of travel. The United States, Israel, and India currently have the highest number of cases associated with this variant outside of the UK, keeping in mind that at the rate at which the pandemic unfolds, these statistics quickly become outdated. In contrast, variant P1 has only been reported from Brazil, and outside of Brazil it has been associated with travellers in a small number of countries. 

Immune responses

Changes in viral proteins may or may not influence certain characteristics of a viral infection. Current epidemiological data and modelling have all suggested that the VOC circulating in South Africa and the UK are more transmissible than previous lineages of the SARS-CoV-2. Despite the increased transmissibility, to date the severity of illness and the proportion of severe disease in different age groups appear to be unaffected by the changes in the protein. The increased transmissibility has increased the burden on the public and private health systems, emphasising the importance of rolling out a vaccine to healthcare workers and persons at increased risk of severe illness. 

The changes in the spike protein responsible for inducing immune responses have sparked research studies to determine whether the vaccines will be able to protect against the new variants.  It must be remembered that there are two arms to the immune response with complex interactions, and that natural protection will likely be a combination of responses. However, the presence of antibodies that neutralise the virus, in other words, block it from entering cells, and the ability of these neutralising antibodies to block new variants from entering the cells, can be investigated in the laboratory. Although the exact responses required for protection are not fully understood and will require studies that take more time to complete, an indication of neutralising capacity provides some information with regard to the potential efficacy of the vaccine against variants. What we currently know from laboratory research is that there is a reduction in the ability of antibody from people previously infected during the first wave of cases to neutralise the new variant circulating in South Africa. This reduction varied among the cohort of samples tested, but overall, there was a weaker neutralising capability. Similar results were demonstrated using pseudoviruses representing the variant virus. Studies looking at antibodies in people who have been vaccinated show similar reductions in neutralisation. The answer is unfortunately not clear at this stage, with many pieces of the puzzle still to be determined. The reduced capacity to neutralise in a laboratory was not what we wanted to hear, but it must be remembered that vaccines induce a broad immune response and not only neutralise antibody, and hence there are other components to the immune response that will likely contribute to protection. Nonetheless, even a reduced immune response will contribute towards vaccine-induced herd immunity and saving lives by preventing severe disease. 

Vaccine trials

In addition to the vaccines currently in use, results were released from clinical trials using vaccines from Novavax and Johnson & Johnson. Although a lower efficacy was shown among the South African population compared to results obtained in the UK, the efficacy was still in the region of 57% to 60%, which is certainly encouraging in view of the new variant circulating. The differences observed illustrate the importance of conducting vaccine trials in local populations. An efficacy of 60% will still contribute towards herd immunity and the prevention of severe disease, emphasising the importance of a rapid roll-out and hopefully a high uptake of the vaccine. Vaccination will not only protect the vaccinee but should contribute to minimising the risk of further variants emerging. 

The roll-out of vaccine, further research on immune responses in vaccinated communities, epidemiological data, and sequence data will all contribute towards monitoring the evolution of the outbreak. Flu vaccines are modified annually and if the COVID-19 vaccine needs to be modified, manufacturers have the capability to do this, and some have already started this process. 

Additional waves of infection are predicted to occur until herd immunity can be achieved. Whether the current variants will be responsible for the next wave is not possible to predict, and continued research analysing the gene sequences of future isolates will play an important role in determining how the virus is evolving. 

In the interim, until we have sufficient vaccine-induced herd immunity to provide protection, non-pharmaceutical interventions and human behaviour will continue to play the important role of minimising new infections. To quote CS Lewis: “You can’t go back and change the beginning, but you can start where you are and change the ending.”

 

News Archive

School of Open Learning opens access to education
2011-12-08

 

Lanterns filled the night sky as UFS staff and guests celebrate the launch of the School of Open Learning at the university’s South Campus.
Photo: Johan Pretorius

A school which intends to expand the boundaries of the University of the Free State (UFS), providing good quality higher education that is based on open learning principles. That is what the School of Open Learning at the UFS’ South Campus is all about. The School was officially launched at the Campus on 28 November 2011. 

Prof. Daniella Coetzee, Dean of the School, told guests at the launch that the School will provide opportunities other than traditional learning in higher education and open up access to those who have not had the opportunity to study at a higher education institution. This includes taking programmes and courses to students at off-campus sites. The School of Open Learning currently has 46 off-campus sites across most of the provinces, i.e. Mpumalanga, KwaZulu-Natal, North West, Eastern Cape, Northern Cape, Limpopo and the Free State. The off-campus sites are serviced by a total of 350 university lecturers and well-trained facilitators and tutors.
 
At the moment most of the programmes and courses managed by the School of Open Learning have their academic home in the Faculty of Education, providing upgrading of the qualifications of teachers as well as in-service training. In 2011 the School of Open Learning enrolled more than 4000 students for the Education courses. To date a total of 28 000 teachers have been enrolled at the School to upgrade their teaching qualifications.
 
Collaboration with the Faculty of Law in the presentation of a BIuris degree on off-campus sites is also on the calendar for 2012. This degree will be offered through contact and E-learning at three off-campus sites: Johannesburg, Durban and Cape Town.
 
The University Preparation Programme (UPP) will also form part of the School of Open Learning. This programme has proven to be extremely successful in providing students access to undergraduate degrees at the UFS. The curriculum for this bridging year offers courses from the Faculties of Economic and Management Sciences, Human and Social Sciences as well as Natural and Agricultural Sciences. Since 1993 more than 4500 students have enrolled for degree purposes after successfully completing the UPP: 1641 degrees have been awarded to students who began their studies in the programme (including 168 honours degrees; 25 master’s and 8 M.B.Ch.B. degrees). The existing foundation course in the UPP is being adapted to also serve NQF level 4 in further education. As far back as 1998, the Sunday Times (Best in Education, 1998:1) named this programme as “one of the most innovative education programmes” in a special supplement on higher education in South Africa.
 
Also speaking at the event, Prof. Jonathan Jansen, Vice-Chancellor and Rector, said the South Campus is to become intellectually alive with possibilities. He said the university will make sure there are seminars, conferences and classes where students can mingle across the university’s three campuses.

 

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