•Experts say surviving Chicken Pox infection, others protect Nigerians from disease
Many medical experts are curious to know why death rates from the novel Coronavirus disease (COVID-19) are low in Africa, especially Nigeria, contrary to earlier gloomy prognosis, compared to soaring figures from other continents. They are wondering if Chicken Pox provides an answer?
Some researchers believe this could explain why current COVID-19 infections are less severe on the continent, arguing that with social distancing, people are being exposed to lesser doses of the virus, just as other scientists postulate that poor countries may have greater protection against the disease because of their harsh living conditions.
Experts have been puzzled why some countries, where poverty and disease is rife, are not suffering massive outbreaks, describing the phenomenon as a “complete enigma.”
At the start of the pandemic, it was feared that poorer countries, particularly in Africa, could be devastated by the virus due to poor hygiene and lower quality healthcare systems in most communities. But paradoxically, it is possible these challenging living conditions may have actually helped impoverished countries to better cope with the coronavirus.
Public health experts say that, because life expectancy is so low in these countries, there are fewer older people, who are particularly vulnerable to COVID-19. And with younger populations, fewer people are dying from the disease or falling ill enough to be hospitalised.
It is suggested that people living in the poorest places may have actually been exposed to more coronaviruses and flu bugs, because they live in such crowded areas where diseases spread rapidly. Science has repeatedly suggested that exposure to other similar viruses may afford people an extra layer of protection against COVID-19.
According to the World Health Organisation (WHO) situation report on COVID-19 of September 17, Africa has witnessed declining trends in the number of new cases reported (a 14 per cent decrease in cases and a 15 per cent decrease in deaths in the past seven days), with 26 of the 47 affected countries reporting decreases in the past week.
The WHO, however, said while this is encouraging, vigilance is still essential, as many factors could be influencing these trends, such as testing capacity and strategy, as well as delays in reporting in some areas.
Director General of the Nigerian Institute for Medical Research (NIMR) Yaba, Lagos, Prof. Babatunde Salako, acknowledged the possibility that previous exposure to other viruses by many Nigerians may have a protective effect, adding: “The tropical environment that we live exposes us to several other microorganisms that may have prepared our body for similar future infections. Chicken pox is probably just one of them.”
A public health physician and Executive Secretary of Enugu State Agency for the Control of AIDS (ENSACA), Dr. Arthur Chinedu Idoko, noted: “I believe strongly and have always reasoned that something in the African man in the sub Saharan Africa is accounting for most cases of the less severe manifestations of COVID-19 experienced in our environment.
“The nature versus nature has probably made us resilient to strains of COVID-19. It could actually be the immunity derived from other suffered and recovered from viral infections, such as Chicken Pox, or prevalent and endemic disease conditions we experience every now and then in this environment, treat and successfully recover from that may have conferred on us some degree of immunity hence some protection.
“Poverty, on the other hand, as a protection factor, probably indirectly correlates with this view point. The environment of living, the nature factor, all probably plays a role.”
For the Medical Director of Medical Art (MART) Centre in Maryland, Lagos, and Joint Pioneer of In Vitro Fertilisation (IVF), Prof. Oladapo Ashiru: “Chicken Pox and the vaccinations can also render some protection.”
Ashiru, who is also an adjunct professor at the University of Illinois-Chicago in the United States (US) and President of African Fertility Society (AFS), explained further: “There have been a number explanations. The fact that there may be the sub Sahara immunity from endemic malaria and other parasitic infection is possible. The presence of Vitamin D from sunlight is also a factor, as Vitamin D protects against COVID-19, based on some reports.
“Most people in Nigeria would easily go to the pharmacy and get antimalarial medications once they have fever, cold and headache. They would only seek medical advice when they do not get better. Such antimalarial with the quinines may offer protection.
“Lastly, a number of people will resort to various herbal tea, such as dongoyaro (neem tea/azadirachta indica) and more.”
But a virologist and Chairman, Expert Review Committee on COVID-19, Prof. Oyewole Tomori, said: “These stories about chicken pox, etc, are speculative.”
Tomori, who is also the pioneer vice chancellor of Redeemers University, Ede, Osun State, and a consultant to the WHO, however, added that certainly, a previous infection with a related virus would protect from or prevent a full blown infection.
“For example, people with previous infection with West Nile virus or may be Zika virus may lead to a mild outcome of a latter infection by Yellow Fever. That was how people milking cows and who got cowpox virus infection, which is related to smallpox virus, end up getting protected from small pox or end up with a mild smallpox disease.
“But Chicken Pox virus is not related to COVID-19 virus, so it is difficult to say its infection protected or will protect against COVID-19. Again, we do not have information on what other infections the person might have had and if he or she has had a previous infection, perhaps a mild/asymptomatic infection with a related Severe Acute Respiratory Syndrome Coronavirus Type One (SARS-CoV).”
A virologist/vaccinologist, former researcher at the National Institute for Pharmaceutical Research and Development (NIPRD) and Founder/Chief Executive of Innovative Biotech in Keffi, Nasarawa State, Dr. Simon Agwale, told The Guardian: “COVID-19 death rates have been low in Nigeria and many scientists are puzzled by this low rates. While studies are ongoing to unravel this, it is important to note that younger people are more likely to suffer mild symptoms.”
“According to a study of over 17 million people in England, published in Nature, patients older than 80 were at least 20 times more likely to die from COVID-19 than those in their 50s, and hundreds of times more likely to die than those below the age of 40.”
Agwale, who was recently elected to lead COVID-19 vaccine task team of the African vaccine manufacturing, said other reasons why Nigerians are more protected against COVID-19, compared to the Europeans and Americans, could be because Nigerians have had more exposure to other coronaviruses, which may provide some natural immunity against COVID-19.
“Furthermore, regular exposure to other infectious diseases that subject our immune system to constant boosting may contribute to this low fatality rates.
“We cannot also rule out the role of genetic factors. The unfortunate thing is that there are no serious research activities going on in the country to enable us address these issues,” he said.
But Director General of the Nigeria Centre for Disease Control (NCDC), Dr. Chikwe Ihekweazu, stated: “We are not aware of any scientific studies that have identified poverty or Chicken Pox as protection against COVID-19.
“We are working very hard to implement public health research that will enable us identify factors that may be associated with the case fatality rate in Nigeria, including a household sero-survey scheduled to begin in September.”
Meanwhile, some scientists argue that the reason for the low fatality rate of COVID-19 might also be that the infection is being passed around at a low dose due to adherence to safety protocols of social distancing, hand washing, wearing facemasks, etc.
A virologist at St George’s University of London, Dr. Elisabetta Groppelli, said: “If you are exposed to a smaller amount of virus, fewer cells in your body get infected, so there’s time for your immune system to mount a response. If you get lots of cells infected at once, you are already starting on the back foot. There is not particularly solid data for COVID-19 at the moment, but it is logical.”
Many comparisons have been drawn between COVID-19 and the Spanish flu pandemic of 1918, and interestingly, this theory would offer an explanation for what happened then, too.”
Indeed, compared to Western countries, African countries have suffered just a fraction of cases and deaths. The continent, which has recorded little over a million cases, has the second lowest death rate in the world after Asia.
There have been over 21,000 confirmed coronavirus deaths in Africa, 10 times fewer than in Europe and 20 times fewer than in the Americas. Africa has recorded little over a million cases, against 4.2million in Europe and 13.1million in the Americas. Scientists suggest this could in part be because the countries have a low average age, just 28, compared to 48 in Italy and 40 in the UK.
Testing in Africa is nowhere near the scale seen in other continents, which means there could be a huge degree of underreporting when it comes to infections and deaths. But the difference is stark, nevertheless.
Some experts have cited young populations for Africa’s relatively low infection and death rates. The average age of an African is 19, compared to 40 in the UK and most places in Europe and the US.
Life expectancy on the impoverished continent is just 64 years, compared to 81 in the UK. And data shows that COVID-19 has disproportionately affected elderly people, particularly those in their 70s and 80s. This disproportionate effect on older people may be one explanation for why less developed countries appear to be faring much better than their wealthy, advanced European and American counterparts, where people live longer.
A growing body of research has suggested that people may already have immunity, as they have had similar illnesses in the past. Experts have observed that the infection looks extremely similar to other, milder strains of coronaviruses, which cause coughs and colds and circulate regularly, and may have some level of “cross-protection,” which means they are not seriously harmed by COVID-19.
There is consensus that while it remains unlikely that people would be totally protected from any infection at all, “background” immunity could make their illness less severe and death less likely.
It is believed that people living in the toughest conditions have probably been infected by other coronaviruses that cause common colds, which have given them antibodies to be able to fend off COVID-19.
