Virologist. Professor of Microbiology and Global Health. Elected member, Academy of Science of South Africa. Founding Director, SAMRC-UNIVEN Antimicrobial Resistance and Global Health Research Unit. Associate Editor, South African Journal of Science.

Author: Pascal Obong Bessong

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Cat Links Viruses

Variants of SARS-CoV-2

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  SARS-CoV-2 has RNA (ribonucleic acid) as its genome, so it falls under RNA viruses. Changes in the genome are very common among RNA viruses, compared to viruses which have DNA (deoxyribonucleic acid) as the genome. This is because the changes that occur in the RNA genome during the replication of the virus may not be corrected and are passed on to progeny viruses. Since thousands of viruses are produced in each replication cycle, these changes are amplified in the viral population, leading to a pool of viruses from the same parent, but not identical in the genome. This is called genetic diversity. The changes that occur in the genome of any organism are called mutations. For viruses, the type and extent of the mutations are used to classify the different members of the same virus as strains, variants, types, subtypes, groups, subgroups and so on. Examples of other RNA viruses that infect us and display high genetic diversity include influenza virus and human immunodeficiency virus. Mutations can be lethal to viruses, but they can also bring benefits to viruses. These benefits include making them more efficient in infecting their host and increase their ability to evade the immune system and vaccines. Mutations can also reduce the effectiveness of diagnostic tests, and medicines directed against the virus. It is rational to be wary of the potential benefits endowed in new variants of SARS-CoV-2. At the same time, this knowledge is very important for the continuous rational design and implementation of biomedical interventions. It is useful to also note that non-pharmaceutical interventions such as hand washing and sanitizing, wearing of masks, ventilating enclosures, avoiding crowds, and keeping social distancing will remain highly effective against any variant of SARS-CoV-2. Therefore, there is no need to panic whenever a new variant of SARS-COV-2 is announced. Scientists have the duty disclose their findings for the benefit of society. Since all variants of SARS-COV-2 are destroyed by soap and alcohol, and do not stay for long suspended in the atmosphere, we should continue to adhere to the non-pharmaceutical measures, and crown this with vaccination against Covid-19. Vaccines for Covid-19 will improve as our understanding of the virus and how it interacts with our bodies improve. Science is for the society, so any discovery of science is for the good of the society. The release of scientific information should not attract negative reactions but should instead be used positively. https://www.theguardian.com/commentisfree/2021/nov/28/scientists-sharing-omicron-date-were-heroic-lets-ensure-they-dont-regret-it. All of us should be interested in the science of germs. We may not understand everything, but we would have a strong understanding of the findings of science for our own rational use and behaviour. Again, science is for society! Home

Cat Links Antimicrobial resistance, Antiviral resistance

HIV infection and HIV drug resistance

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HIV infects and destroys cells that fight germs in our bodies. The medicines used to prevent the multiplication of HIV in our bodies are called antiretrovirals. There are different types of antiretrovirals, each of them targeting a different part of the virus. To prevent the multiplication of HIV, in a substantial way, a combination of antiretrovirals is used at the same time (combination therapy). The goal of combination therapy is to reduce the amount of virus in our bodies to a very low level and quickly too, so that those cells in our bodies that fight disease are no longer killed by HIV; and are produced in good number and quality to do their work. Also, when the amount of virus in our bodies is small, the chance of transmitting the virus to others is also low. As a result, treatment for HIV is now considered as an important tool for prevention. One major challenge to the outcome of antiretroviral therapy is the emergence of HIV that is resistant to treatment, that is drug resistance. When HIV is no longer destroyed by a combination of antiretrovirals, then the virus is not controlled in our bodies. This also means the treatment has failed. Therefore, another combination needs to be decided upon, after finding out why the initial combination failed. Alternative combination therapies are, many times, not easily accessible, have more side effects, and are more expensive. HIV develops resistance by making changes to sections of its gene that lead to ineffectiveness of a drug that had an effect on those sections. Our roles to prevent the development of HIV drug resistance Research has shown that poor adherence to treatment is one of the major contributors to the development of HIV drug resistance. Other contributors include how our bodies breakdown the medicines, availability, and accessibility. Poor adherence is when an individual does not take medicines as prescribed, and this can be due to psycho-social factors. These include the mental state of the individual and how society relates to those who are HIV infected. Individuals and communities can help people on HIV treatment to reduce the chance of drug resistance development. We know that HIV treatment is long-term, so we can support our friends and relatives by encouraging them to stay on treatment and remind them to get refills, we should not discriminate against those with HIV at home and at the workplace, we should be sensitive to the challenges they may have such as decisions for family, education, and getting employed and staying on the job, or starting their own business. In short, we should be buddies to those on HIV treatment so that we can provide the social and environmental support they need to prevent the development of drug resistance, get cheaper treatment, not endure more severe side effects from alternative drugs, and live near-normal lives. Resistance to HIV treatment is of global concern and it is an aspect of Antimicrobial resistance. You can read more about the relationship between adherence, HIV drug resistance, and viral suppression here https://pubmed.ncbi.nlm.nih.gov/33407664/

Cat Links Antimicrobial resistance

Antimicrobial resistance

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Antimicrobial resistance is when a germ thrives in the presence of a medicine that previously inactivates or kills it. Generally, medicines that kill germs are called antimicrobials. Antimicrobials have played and continue to play a great role in the promotion of global health, socio-economic development, and advancement of nations and civilization. The discovery of penicillin is a case in point. So, it is of huge concern when antimicrobials begin to lose their efficacy as a result drug resistance development. There are several reasons why germs do develop resistance to medicines. One reason could be that a strain of the microbe that was naturally resistant multiplies and becomes the majority strain. A second reason is when, over time, a microbe develops ways to avoid the medicine. Antimicrobial resistance is a big problem all over the world. This is because it makes cheap available medicines useless. As a result there is much suffering from infectious diseases and deaths. However, individuals have a vital role to play in the control of antimicrobial resistance. This can be done by taking only the medicines prescribed by an authorized health care personnel, for the duration prescribed, and by purchasing medicines only from authorized vendors. It can be difficult for some people to practice these, for example, when one cannot access a health care facility for prescriptions or when counterfeit medicines find their way into legitimate supply chain processes. Communities of low socio-economic status suffer the most from antimicrobial resistance. This is mainly because individuals from these communities cannot afford the expensive alternative antimicrobials. This can make people die from a germ causing illness because the medicines they are given do not kill the germ and there are no affordable options. This can happen for viral, bacterial, fungal or parasitic infections. As we noted in another post HIV infection and HIV drug resistance, resistance to HIV drugs is a threat to the treatment and elimination of HIV infections. The objective of global health research and education is to improve access and equity to healthcare. However, it is very important for the perspective and voice of communities, particularly communities of low socio-economic status to be heard. This is because the strategies or interventions developed to support communities would have a higher chance of success and sustainability in a partnership between science and communities. Antimicrobial resistance is a global problem. In 2015, the World Health Assembly described efforts to reduce antimicrobial resistance as a global priority. It threatens the usefulness of available medicines, and the health and socio-economic development of communities. It takes years and a lot of resources for a new antimicrobial to be developed, so it is very important that available antimicrobials remain effect and accessible to all. A study which I lead, showed that even in young children, who are not sick and have never received antibiotics, you can find gut bacteria that have genes coding for a variety of antibiotic resistance http://www.samj.org.za/index.php/samj/article/view/11819/0. It is very important to find out how these young children acquired antibiotic resistant bacteria so early in their life. The answers may lead to the design of appropriate measures to prevent its occurrence. Dr Richard Guerrant, University of Virginia, USA https://globalhealth.virginia.edu/Guerrant, and myself have advocated, through a guest editorial for the South African Medical Journal, for surveillance of antibiotic resistance to be carried out at the population http://www.samj.org.za/index.php/samj/article/view/11827. If we do this, we can better understand the burden and dynamics of the problem. Sustained efforts from different angles are needed to curb the rise of antimicrobial resistance. This is because there are different causes of the development of antimicrobial resistance: the unnecessary prescription or under prescription of antimicrobials, the use of antibiotics in livestock, self-medication, and the use of counterfeit substandard medicines. It will be interesting to know your views about antimicrobial resistance, and what you think individuals and the lay leadership in communities, such as non-governmental organization, can do to control and prevent antimicrobial resistance development and spread in communities.

Cat Links Child health and development, Vaccines

The MAL-ED project

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A summary of the MAL-ED Project is worth highlighting. It was a landmark investigation. The MAL-ED Project, the short name for – The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health – is to date, the largest study carried out in different countries and continents, to observe how infections in the large intestine of young children interact with the workings of their gut; how they affect children’s response to vaccines, and how the infections affect their growth in stature and in cognition (https://www.fic.nih.gov/About/Staff/Pages/mal-ed.aspx). The study was funded by the Bill and Melinda Gates Foundation, and administered jointly by the Fogarty International Center of the National Institutes of Health, USA; and the Foundation for the National Institutes of Health, USA. The MAL-ED Project was carried out in Brazil, Bangladesh, India, Nepal, Pakistan, Peru, South Africa and Tanzania. The South Africa site was at the University of Venda (http://univen.ac.za ), and was lead by Professor Pascal Bessong. The study showed that a combination of intervention factors will be required to improve response to oral vaccines, school performance, and social advancement. One of the important findings is that children can suffer in ways that are not obvious due to a high burden of germs in their intestines, and this can negatively impact their education and socio-economic development later in life. The recommendation of the investigators is that a combination of interventions should be used to reduce the negative effects of intestinal infections in young children as they are grow older. The video above gives a summary of how the MAL-ED Project was carried out, the findings, and the recommendations. This was a successful community-based study. It involved engagement with a prospective community on the objectives of the study, for the community to understand the benefits that may accrue to them, and how they prefer to participate. In the South Africa site, in the Limpopo Province, field workers including nurses and data collectors were recruited from the community with the assistance of the community leadership, and trained for competence to collect quality datasets on disease and treatment surveillance; anthropometry; stool, urine, and blood collection; and feeding history for first five years of a child’s life (https://academic.oup.com/cid/article/59/suppl_4/S317/279507) The study provides evidence that communities of low socio-economic status can understand, contribute, mobilize and participate in intensive, longitudinal, observational, biomedical studies (Home). The study participants received regular feedbacks on the findings of the study, and the evidence they can use in their advocacy efforts towards improvement of their well-being. Society’s participation in scientific research can be very enriching, not only from the findings of the study itself, but also from the several spin-offs that contribute to the attainment of the sustainable development goals of the United Nations and African Union Agenda 2063 (https://doi.org/10.1186/s12889-017-4138-6).

Cat Links Vaccines

Vaccines are a win-win for all: Covid-19

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Vaccines are a win-win for all. Including Covid-19 vaccines. We are all exposed to, and infected by germs, such as bacteria, fungi, protozoans, or viruses. Some will not cause disease, while others will cause serious disease to some of us, sometimes leading to epidemics and pandemics.  One of the most powerful biomedical interventions to prevent the contraction and spread of diseases is vaccination. The Spanish flu of 1918-1920 is estimated to have infected about 500 million people and killed between 20-50 million people; then came flu vaccines that significantly control influenza up till today. We owe the eradication of small pox, and very soon, the eradication of polio mainly to vaccines. The recent containment and control of Ebola in Africa is due to vaccines. All over the world, the significant reductions in child mortality is mainly due to vaccinations against bacterial and viral germs. By receiving a vaccine, we are immunized to the disease the vaccine is directed against. Vaccines have improved human well-being and advanced civilization for decades. As of the date of writing Covid-19, has so far, killed more than five million people worldwide. And more may die in the future. Measures to curb the spread of the virus, such as travel restrictions and the closure of businesses led to enormous disruptions in education, travel, commerce and trade, culture, families and routines of daily life. Many people lost their jobs, others became impoverished, access to health services were disrupted. In the face of these enormous challenges, scientists set to work to develop vaccines against Covid-19. Although the vaccines are different in terms of how they were developed and dosing, they are all aimed at preventing disease, hospitalization, and deaths, and ending the pandemic, something that all of us are very eager to see.   There is a lot of anxiety among a significant proportion of people around the world about accepting Covid-19 vaccines. I have witnessed this anxiety within my own family and among friends and acquaintances. Some people are sceptical about the safety of the vaccines, citing the relatively short time it took to make the vaccines. There reasons why Covid-19 vaccines were developed and available for use within a relatively short time. Some of these reasons include: (1) The availability of advanced technologies for vaccine development. (2) The quick realization the vaccines are well tolerated and safe; and the individual produces enough antibodies that are protective against the virus. Without evidence that a vaccine will be well tolerated and that is there is potential to induce protection, progress is stalled. (3) The rapid availability of volunteers for large vaccine trials so that more data on safety and protection from diseases and hosptalization can be gathered.  (4) The priority given by data management and safety boards (DMSB) and by regulatory bodies to urgently review data from vaccine trials. (5) The ‘financial gamble’ taken by many governments to start manufacturing some of the vaccines once a good chance that they will be safe and protective was perceived. This type of a gamble has never been done before in vaccine production. Some people think Covid-19 vaccines will destroy our DNA. The components of the Covid-19 vaccines do not get integrated into our DNA, so the chance that they will destroy our DNA is almost nil. The mRNA used in the Moderna and Pfizer vaccines is processed in the cytoplasm to produce proteins corresponding to the proteins on the surface of the virus. The viral protein produced in the cytoplasm is what induces the immune response by the host, thereby providing protection when the real virus infects the body. As with all biomedical interventions, there is always room for improvement to enhance efficacy and utility of vaccines, and this happens with the accumulation of data and evidence over time. Covid-19 vaccines are a win-win for all and should be welcome developments; all governments and the private sector should seek ways and means to procure Covid-19 vaccines for their people. Getting vaccinated against Covid-19 and in combination with social distancing, hand sanitizing, and wearing of masks to cover our nose and mouth in public places, and by ventilating our homes more, we can keep the virus in proper check and ultimately eradicate it from our communities.

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Cat Links Vaccines

WHO approves vaccine for malaria!

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The WHO approves vaccine for malaria. The World Health Organization (WHO), this week, approved the widespread use of a new vaccine, called Mosquirix, for malaria. This is the first of its kind against malaria, and it is a huge breakthrough expected to significantly reduce suffering due to the disease, particularly in developing communities where the disease is most common all year round Mosquirix is recommend for the prevention of malaria in young children. African scientists were involved in the development of this vaccine. This is a good indications of the involvement of Africans in finding solutions to biomedical problems in Africa. https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk. Millions of people suffer from Malaria every year. The disease is more severe in children aged 5 years and below, killing thousands every year. Many drugs are available to treat malaria. But, over the years, resistance by the parasite to the most effective and cheap medicines has grown substantially. This means that management of the disease with cheap and common medicines has become difficult in many instances. As a result, poor people who cannot afford expensive alternative medicines, suffer the most. https://bessongthemicrobiologist.com/2021/11/13/antimicrobial-resistance/. This is why the approval of Mosquirix for the prevention of malaria by the WHO is a big development in the management of malaria globally, particularly in the developing world. The socio-economic impact of malaria is also very high, mainly due to absence from work when people are sick of malaria. Malaria is caused by the Plasmodium parasite. There are four types that infect humans: Plasmodium falciparum, Plasmodium ovale, Plasmodium malariae, and Plasmodium vivax. Each of these parasites can be more common in a particular region than the other. Generally, the most common is Plasmodium falciparum. The WHO approved vaccine is recommended for use in areas where Plasmodium falciparum is most common. Plasmodium is transmitted to humans through the bite of the female Anopheles mosquito. The mosquito thrives in tropical and subtropical climates, and breeds in stagnant water. The availability of a vaccine for malaria is highly welcomed; and there is hope that the efficacy of the vaccine will be improved upon as more evidence from its use emerges. As the WHO approves a vaccine for malaria, it is the hope that this will spur efforts in tackling other endemic infectious diseases in the developing world.