By Peter Gambara
Most families have lost a family member, relative, workmate or neighbour during the last couple of weeks to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in China in December 2019. The World Health Organisation (WHO) has declared the outbreak a health pandemic. Zimbabwe, just like the rest of the world, has been hit by the third wave of the virus outbreak. In this article, I seek to explain a few concepts (or mis-concepts) and hope that it will assist us as a nation to get vaccinated or act more responsibly going forward.
SARS-Cov-2 , Covid-19
The virus is commonly referred to as Covid-19, ’CO’ stands for corona, ‘VI’ for virus and ‘D’ for disease. The ‘19’ is because it was first detected in the city of Wuhan, China in 2019.
History of the virus
In December 2019, a large number of people, who had been exposed to the Wuhan wholesale seafood market that also traded in live animals, began to show signs of severe pneumonia and as the number of infected people began to spread exponentially, China had to notify the WHO, who on January 30, 2020, declared it a public health emergency of international concern and subsequently declared it a world pandemic on March 11, 2020 as the virus spread outside China. The massive migration of Chinese that occurs every year in January soon spread the virus quickly to other parts of the world.
Studies have shown that the virus is transmitted through inhalation or contact with droplets from an infected person. Droplets from an infected person can travel up to two metres from the infected person, hence the need for social distancing. The virus can also remain viable on surfaces for days if favourable atmospheric conditions exist, hence the need to frequently disinfect buildings.
The incubation period varies from two to fourteen days and an infected person shows symptoms of fever, sore throat, coughing, losing breath and fatigue. These may deteriorate to pneumonia, acute respiratory syndrome and multi-organ failure. However, more worrisome, it has since been proved that asymptomatic people (not showing the symptoms) are capable of transmitting the virus to others. It is therefore important to just be careful, as the person next to you, who is not showing any symptoms of being infected, might spread the virus to you.
Worldwide control measures
Based on the study of past health pandemics, the WHO have since recommended the use of Non-Pharmaceutical Interventions (NPIs) to control the spread of the virus. During the 1918-19 H1N1 influenza virus several countries responded with the imposition of NPIs to reduce virus transmissions. Current recommended NPIs include:
Frequent washing of hands with water and soap or using a sanitiser (in case you touched an infected surface),
Maintaining minimum distance of 1 metre between oneself and the next person, when in a public place (so that droplets from an infected person may not easily reach you),
Avoiding the touching of eyes, nose and mouth (in case you touched an infected surface, the virus will quickly infect you through the nose, eyes and mouth),
Wearing a mask that covers the nose and mouth when in public (so that even if you are asymptomatic, you do not spread infected droplets to others when you cough or sneeze)
Closing schools, bars, churches and social venues, where people gather in large numbers. These have since been identified as potential super spreader events (the virus will quickly spread to a number of people if one person has the virus).
The elderly and those with underlying conditions like diabetics, high blood pressure and HIV are most susceptible to infections. These groups of citizens should be the first to go and seek vaccinations.
Use of vaccines
After the emergence of the virus and based on previous health pandemics, scientists reached a consensus that the best way to control the virus was to come up with a Covid-19 vaccine. This saw several universities and/or companies coming up with vaccines that have since been approved by the WHO. However, several challenges have emerged with the use of vaccines and these include affordability by low-and-middle-income countries (LMICs), production of enough vaccines to match demand, vaccine hesitancy, the period of protection that vaccination provides, the level of efficacy of each vaccine and the emergence of several variants that resist available vaccines. I will dwell on some of these issues below.
The emergence of variants
Since the outbreak of SARS-CoV-2 in December 2019, several variants of the virus have emerged. Variants of the virus are more virulent and more easily transmitted and can evade vaccination induced immunity. Variants have emerged in the United Kingdom (B.1.1.7 or Alpha variant), South Africa (B.1.351 or Beta Variant), Brazil (P.1/ B.1.1.7 or Gamma variant) and recently, India (B.1.617 or Delta variant). The Delta variant, has since become the predominant strain worldwide and is driving the third wave that we are currently experiencing, whilst the Beta variant drove the December/January wave.
Researchers say the Delta variant is more than twice as transmissible compared to the original virus strain. It replicates much faster than the original strain and individuals infected with this Delta variant have viral loads that are up to 1,260 times higher than those infected with the original strain. This means, if you interact with someone with this virus, it is much easier to catch the virus. This also means those banned super spreader events are likely to infect much more people than before. I have heard a few friends complaining about their elderly parents, who want to attend each and every funeral. Unlike with the first and second wave, this time around, we are getting elderly people who are succumbing to the virus in rural areas. And to make matters worse, they are gone, in a very short space of time.
Herd immunity, vaccine hesitancy
Scientists have argued that the best way to tackle this SARS-CoV-2 virus is for people to have acquired immunity, however, this can only be established at the individual level. A person can get immunity through two ways, either through acquiring natural immunity after one has recovered from an infection or through immunisation with a vaccine. Countries aim to reach herd immunity, which is the indirect protection that citizens get when a sufficiently large number of individuals in a population are immune from the virus.
However, vaccine hesitancy among many citizens across the world is getting in the way of reaching herd immunity. Worse still, countries using vaccines with lower efficacies, might have to vaccinate their entire populations to reach herd immunity. This is against a situation where WHO have said vaccinations are not compulsory. This is further worsened by the fact that vaccines might not offer lifelong immunity. Recently, Johnson and Johnson said their vaccine will last about eight months, which means vaccinations might become a routine exercise.
Therefore, whilst we are still struggling to get some citizens to get vaccinated, those who were early birds to get vaccinated, might soon need to re-join the queue for revaccinations. It is therefore important that where Governments have provided vaccines, the citizens rush to get vaccinated, so that we get herd immunity quickly. Once we are there, the situation becomes much more manageable.
How does vaccination work?
Researchers say Covid-19 vaccines have proved to be effective in reducing the number of infected people who get hospitalised or end up dead. The majority of vaccine hesitant people use the excuse that vaccines do not protect them 100% against getting infected, well, that is true. Vaccines are approximately 80% effective in preventing getting infected, so a small percentage might still get infected. However, it is important to point out the advantages of getting vaccinated.
Firstly, the viral load of a vaccinated person is about 3 to 4 times lower, compared to an unvaccinated infected person, therefore a vaccinated person is less likely to pass the virus to the next person. This means, should you get infected, the chances of you spreading it to your family, workmates or close friends is low. Research shows that a vaccinated person has a 78% less chance of passing the virus to household members. We have had several cases of infections passed on from one member of a family to another, resulting in more than one person in the same family succumbing to the virus. We also have had cases where a husband or wife passes away, but the other half is seriously ill, and cannot even say goodbye to a loved one. Rather than vaccine hesitant people asking what vaccination can do for them, one scientist said, instead they should, ask, “How many people will you harm if you don’t get vaccinated?”
Studies have also now shown that most of those succumbing to the Delta variant might be asymptomatic (not showing signs of illness) and therefore might still pass on the virus to the next person. Therefore, unknowingly, you might pass on the virus to your loved ones. This is one reason people are being encouraged not to assume that one cannot get infected when they interact with friends and relatives. That person, who is your best friend or relative, can actually spread the virus to you, unknowingly, so please exercise caution and wear face masks and observe social distance even when in the company of people, you know.
Secondly, recent studies here and abroad, among those succumbing to Covid-19 have shown that out of those dying from Covid-19, up to 90% of them were not vaccinated. Therefore, do not be among the 90%, get vaccinated and stand a better chance of overcoming an infection.
Lastly, whilst countries like the US and UK were contemplating lifting the requirements for people to wear masks in public places, the recent wave brought about by the Delta variant has forced policy makers to reverse that decision.
Gambara is an Agricultural Economist and Consultant