Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
01 December 2021 | Story André Damons | Photo Charl Devenish
Prof Felicity Burt, expert in arbovirology in the Division of Virology at the University of the Free State (UFS) and the National Health Laboratory Service (NHLS).

Even though not much is yet known about the new COVID-19 variant, Omicron, the presence of a high number of mutations – more than 30 – in the spike protein of the variant raises concern. 

This is according to Prof Felicity Burt, expert in arbovirology in the Division of Virology at the University of the Free State (UFS) and the National Health Laboratory Service (NHLS). According to her, although Omicron is highly transmissible, further epidemiological data is required to determine if it is more transmissible than the Delta variant.

On Friday 26 November, the World Health Organisation (WHO) declared the new variant, B.1.1.529, a variant of concern (VOC) and assigned it the name Omicron. This assignation was based on advice from the Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE), an independent group of experts responsible for monitoring and evaluating emerging variants. The following are considered when categorising a newly identified variant – are there mutations (changes in the viral genes) that are known, or that have the potential, to affect the characteristics of the virus, such as transmissibility, disease severity, immune escape, diagnostic or therapeutic escape; is there significant community transmission or increasing prevalence in multiple countries over time; are the public health and social measures effective against the variant.

With each new variant, the public health concerns are dependent on the transmissibility of the variant, the ability of the virus to escape immunity from natural infection or from vaccination, and the severity of illness caused by the variant or any change in clinical presentation. In addition, the ability of current diagnostic assays to adequately detect the variant and effectiveness of public health and social measures, must be considered.

We know, we don’t know 

Answers are derived from existing epidemiological data, laboratory research, and theoretical considerations. Although we can make some predictions based on the mutations identified and the location of these mutations, the epidemiological data and laboratory research are essential to answer with certainty, and this can take some time. The presence of a high number of mutations – more than 30 – in the spike protein of Omicron, raises concern. What do we know and what don’t we know?

“What we don’t know is whether these mutations have changed the severity of disease caused by the virus. We do know that the diagnostic PCR tests currently used in South Africa are not compromised by the presence of these mutations, and in fact, one of the molecular assays commonly used to target three regions of the virus, can be used as a rapid biomarker to detect the variant. Although sequencing of the genome is used as confirmation, this assay provides a useful rapid biomarker that can be used to detect the presence of the variant; subsequently, PCR results have shown that the variant is likely already present in most provinces in the country,” says Prof Burt, who currently holds an NRF-DST South African Research Chair in vector-borne and zoonotic pathogens research. 

There is also preliminary epidemiological evidence that reinfections are occurring. According to her, the occurrence of reinfections suggests some degree of immune escape; however, we do not know the extent of immune escape or the contribution of waning immunity towards reinfections. “Laboratory tests, in which the live virus is tested against samples from both recovered and vaccinated people, are required to confirm whether existing antibodies can neutralise the variant. The tests for neutralising antibodies require specialised facilities and is dependent on culturing the virus. 
“These tests are already underway in the country and should provide more information in the coming weeks. 

Neutralising antibody tests, although time consuming, are relatively easy to perform compared to tests to determine the role played by other arms of the immune response.”

Vaccines still best option to fight COVID-19

Prof Burt, who has worked on viral haemorrhagic fevers and arboviruses at the National Institute for Communicable Diseases (NICD), says it is known that vaccines are highly effective in reducing the severity of disease and fatalities in individuals infected with other variants, such as Beta and Delta, despite mutations in critical regions of the spike gene in the variants. 

The epidemiological data acquired from cases and the results of laboratory tests for neutralising capability will contribute towards understanding the effectiveness of the vaccine against Omicron. The questions regarding severity of the disease and level of protection from previous infection and vaccines are priority areas to understand the impact of this variant. The early identification of the variant and the initiation of vital research and data analysis highlight the importance of genomic surveillance.

Cases of Omicron have already been confirmed in Israel, the United Kingdom, Europe, Australia, and Africa. Travel restrictions have previously been shown to be ineffective in stopping the geographical spread of new variants, merely delaying the inevitable, and at significant cost to economies. “We know with certainty that vaccination has reduced the severity of illness and death with previous variants; even in the face of reduced neutralising ability, there was sufficient protection to save lives,” says Prof Burt.  

She concluded, “Globally, the impact of vaccination is evident in countries experiencing fourth waves, with a reduced number of deaths compared to previous waves. Many decisions in life are based on a risk assessment and consideration of the pros and cons. Vaccines save lives. Vaccines definitely boost waning immune responses from natural infection.” 

“This is certainly not the time to reject the vaccine based on perceived risks from inaccurate social media spreading harmful disinformation compared to the known risks associated with contracting COVID-19 and the known protection against severe disease afforded by the vaccines.”

News Archive

Farmers need to plan grazing better, says UFS expert
2017-02-21

Description: Prof HO de Waal Tags: Prof HO de Waal

Prof HO de Waal, affiliated researcher
at the University of the Free State,
says farmers should save grazing
during the summer months to have
fodder available in the winter and
early spring.
Photo: Theuns Botha,
Landbouweekblad

“Farmers should save veld during the summer months to have grazing available for animals especially in the winter and early spring. Farmers should also adjust livestock numbers timely and wisely according to the available material in the field,” says Prof HO de Waal, professional animal scientist and affiliated researcher in the Department of Animal, Wildlife and Grassland Sciences at the University of the Free State.

He offered this advice as a result of the sporadic and scattered (scant) rainfall of the past couple of summers. “In retrospect we know that this kind of precipitation started in about 2014 and has continued in subsequent summers. In February 2015, it was clear that a major fodder scarcity was developing.”

Existing research methods serve as source of current knowledge
Dr Herman Fouché (Agricultural Research Council) has conducted research on the impact of climate, especially rainfall, on the growth of grass. Sophisticated computer technology developed as far back as the 1980s to – through modelling – predicts the impact of climate on field production during the growing season.

The impact of climate, and more specifically rainfall, on field production has been known to animal and grazing scientists for a long time. Prof De Waal used the modelling results to determine the impact of rainfall on grass as a feeding source for animals.

“Information that emerged from this old research programme could therefore be applied directly to animal production,” says Prof De Waal.

Adjust livestock numbers to availability of grazing
In the summer rainfall areas of South Africa, grass usually grows from the end of August and early September. The growth process is dependent on the transfer of soil moisture, as well as on rainfall during the winter and early spring.

“Livestock numbers should be balanced throughout the year (according to the nutritional needs and production of the animals) with the availability of grazing material – be consistent, not only during certain seasons or when drought is imminent,” is Prof De Waal’s advice to farmers. “Farmers are also encouraged to carefully reduce the number of livestock on grazing and to rather focus their attention and limited resources on the remaining breeding herds (cows and ewes).”

“It is tragic, but unfortunately many farmers will not survive the effects of recent years. Similar climatic conditions will occur, with the same tragic consequences for man and beast. Better planning has to start now.” The assistance of private institutions, individuals, as well as the government, during the severe droughts is gratefully acknowledged.

Spineless cactus pear as solution for scarcity of animal feed
Prof De Waal says spineless cactus pears could be used as a feeding source during droughts. “The effects of a severe drought, or major animal-feed scarcity, are still prevalent in large parts of the subcontinent.” This may act as a catalyst to utilise spineless cactus pears as a feeding source and to be incorporated in the feed-flow programme for livestock on natural grazing.

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept