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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

OSM opening concert 2012
2012-03-02

 

The OSM Camerata is going to shine in the very first annual OSM opening concert.
1 March 2012


 

OSM opening concert 2012 with the OSM Camerata
Conductor: Nicholas Nikolaidis
Date: 1 March 2012
Venue: Odeion
Time: 19:30

The OSM opening concert 2012 with the OSM CAMERATA will be streamed live on the internet with the generous support of OSM partner, LA MUSE AUDIO & LIGHTING (www.ufs.ac.za/ufslivestreaming) in collaboration with the UFS LIVE STREAMING UNIT.

The OSM Camerata is going to shine in the very first annual OSM opening concert. The ensemble will be conducted by Nicholas Nikolaidis. The programme includes excerpts from Stabat Mater (Pergolesi), Romanian Folk Dances (Bartók), Pelimannit (Rautavaara), Elegy (Grové) and Purple Haze (Hendrix). since 2011, the Odeion School of Music has embarked on a new, innovative strategy striving towards uncompromising excellence and internationalisation, which includes the A-List scholarship programme and a new flagship chamber ensemble, the OSM Camerata. Talented South African, conductor/tenor Nicholas Nicolaidis, (runner-up in the First National Len van Zyl Orchestral Conducting Competition) will take the stage for the inaugural concert of the OSM.

Nicholas started his conducting career at an early age while still in the Drakensberg Boys’ Choir School. Professionally his first conducting post was as choirmaster and conductor of the choir and band at Pridwin Preparatory School (Melrose, Johannesburg) in 1996.

Following his appointment in April 1997 as the Musical Director of Côr Meibion Cymru de Affrig (The Welsh Male Voice Choir of South Africa), he conducted the choir for seven years, producing three albums. One of the highlights was the performance at the Royal Albert Hall in London in October 2000 for the Millennium Festival of Male Voice Choirs.

His orchestral conducting debut was in 1998 at the Johannesburg City Hall where he conducted the Johannesburg Festival Orchestra and the Symphony Choir of Johannesburg in a few items of ‘Last Night of the Proms’. Selected conducting performances include the Chanticleer Singers in a performance of Schubert’s Mass in G at the Holy Trinity Church (Braamfontein, Johannesburg) in 2002, and the Johannesburg Camerata, a chamber orchestra consisting of talented young performers, during their winter season in 2005.

In 2006, Nicholas enrolled at Stellenbosch University for a Master’s degree in Choral Conducting under the direction of the Norwegian pedagogue, Kåre Hanken. During this time, he also conducted the Johannesburg-based chamber choir, Collegium Vocale. He conducted the Johannesburg Chamber Wind Ensemble from 2006 to 2008.

In 2009, he conducted the Johannesburg Festival Orchestra in a programme of music by Leroy Anderson, the vocal ensemble, In Verse, and the Chanticleer Singers during their Christmas season. Nicholas was also the winner of the inaugural Young Choral Conductors Competition held during the Stellenbosch International Choral Conducting Symposium in March 2009.

In February 2010, he was awarded the Silver Medal in the inaugural Len van Zyl Conducting Competition held in conjunction with the Cape Philharmonic Orchestra. During the Easter period of 2010 he conducted Cantamus Corde in a performance of JS Bach’s St John’s Passion, whilst also singing the role of the Evangelist.

Nicholas has also appeared as guest conductor of the Philharmonia Choir of Cape Town in a concert with music by Ramirez and Klatzow. In that year he also conducted the gala Concert of the Brooklyn Theatre (Pretoria).

Refreshments will be on sale before and after the concert.

Admission:
R60 (adults)
R40 (pensioners, students and learners)
Tickets available at Computicket.

Enquiries:
Ninette Pretorius (Tel: +27(0)51 401 2504)


 

 

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