Renowned professor of virology, Oyewole Tomori, says in order to bring the COVID-19 global pandemic under control, immunity must be built up all the time by increasing the number of protected persons.
He said it was the reason the world may need to vaccinate about 70 to 90 percent of its population to bring the contagion under control.
He noted that the more people receive the vaccine, the better chances the world has at curbing the spread of the contagion, saying it will provide herd immunity.
The World Health Organisation described herd immunity, also known as ‘population immunity’, as the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.
The agency stated that it supports achieving ‘herd immunity’ against COVID-19 through vaccination, not by allowing a disease to spread through any segment of the population, as this would result in unnecessary cases and deaths.
Speaking with correspondent, the former Vice-Chancellor of the Redeemer’s University Nigeria explained that it was a case of a larger number with immunity protecting those who are not immune.
“Understanding how herd immunity works is not hard. It is a simple arithmetic. It is dynamic, not static. Let me give an example. Supposing we are 10 in a room and eight are immune because they have been vaccinated. That means that only two persons are unprotected.
“Let us assume that a mosquito that has yellow fever virus enters the room. The chances of mosquito biting the other two will be very slim because of the eight other persons who are protected.
“Even if the mosquito bites a protected person, there would be no disease or anything to spread. Imagine if it was the other way round. A situation where two are protected and the other eight are not. The chances of mosquito biting one of the eight is high. Remember that if it bites the other eight who are protected, nothing will happen. That’s what herd immunity is all about,” he said.
The virologist, however, maintained that the course of herd immunity is not static as some people would think.
“Consider the same situation in another way. Let’s say there are eight of us who are protected in the room of 10 people. If 20 other persons come into that same room and none is protected. It means you have diluted the protection. It will now be a case of 22 unprotected versus eight protected persons. The chances of mosquito biting anyone will be very high.
“So, you need to build up immunity all the time by increasing the number of protected persons around,” he said.
Tomori stressed that it was the reason the world may need to vaccinate about 70 to 90 percent of its population to bring the disease under control.
He disclosed that the more people receive the vaccine, the better chances the world has at curbing the spread of the contagion.
“The way things are at the moment, there will always be people who will refuse the COVID-19 vaccine.
“There will also be people who, even if they get vaccinated, will not develop immunity. This may continue until we vaccinate about 70 per cent of the global population. We are talking about years from now.
“If you get the vaccine today, it does not mean you will also get the immunity today. It is not immediate because it takes time to act in your body. This might take up to seven or 10 days,” he said.
The virologist was emphatic that during the early period of vaccination, a person can still contact the virus.
“You will still get infection if you are exposed to COVID-19 because your body’s immunity is not strong enough. Remember too that you have to go for a second dose of the COVID-19 vaccine a month after.
“That will further boost your immunity. As I said earlier, there are too many factors involved. It depends on people’s cooperation and collaboration. The more people that receive the vaccine, the better we will be,” he said.
Director General of Nigerian Institute of Medical Research, Prof. Babatunde Salako, seems to support the same view.
He reaffirms that it is expected that some Nigerians would refuse to accept vaccination as a way to bring the virus under control.
“But again, Nigerians will have to choose between dying and staying alive,” he said.