Covid-19 ‘may become as common as the cold’
A medical worker of the Medical Emergency Services of Madrid (SUMMA 112) runs a rapid test for Covid-19 at the Lope de Vega Cultural Center in the Vallecas neighbourhood, in Madrid, on October 1, 2020
What you need to know:
- Individuals may become re-infected after recovery, as is the case with the common cold.
- For Covid-19, it is widely believed that this is attained when 50 to 70 per cent of the population has been exposed to the virus and developed antibodies.
Although studies show that most Covid-19 patients who recover develop antibodies, it remains unclear if the immunity protects them from subsequent infection and how long the protection may last.
This makes re-infection possible within as short as three months after first diagnosis. Dr Ambrose Agweyu, the head of epidemiology and demography at the Kemri-Wellcome Trust Research Programme, said Sars-CoV-2 may ultimately become as common as the other four endemic human coronaviruses — HKU1, HCoV-NL63, HCoV-229E, and HCoV-OC43.
“As more people are exposed to the virus, it may eventually establish itself in the human population, and the virus may become endemic just like the common cold. Immunity to the other coronaviruses is short-lived and we are currently trying to address the question of how long the immunity to Sars-CoV-2 may last,” he said.
Re-infected
This means that individuals may become re-infected after recovery, as is the case with the common cold.
It raises questions on the likelihood of naturally acquired herd immunity, which is attained when a sufficient proportion of the population has gained immunity thus limiting further spread.
For Covid-19, it is widely believed that this is attained when 50 to 70 per cent of the population has been exposed to the virus and developed antibodies. In a research done in May, the Kenya Medical Research Institute (Kemri) established that only five percent of the adult population had been exposed.
Antibodies
With a threat of reinfection and consequent unabated transmission, herd immunity, based on the results of antibody testing may not be attained in the country any soon.
This is despite declining infections especially in major urban areas. But, there is still hope as immunity derived from antibodies alone may not fully answer to immunity against Covid-19, said Dr Agweyu. T-Cells, a separate arm of the immune system, could also contribute. Dr Agweyu said that, although mutations are common in viruses, the majority have no public health consequences.
Research has shown that although Sars-CoV-2 has mutated to a more “transmittable form”, the mutation is much slower compared to other viruses.
