There has been some debate on the term “herd immunity” and also if it is going to help in combating the deadly coronavirus.
British Prime Minister Boris Johnson first floated the idea to tackle the pandemic by suggesting that it would control the spread of COVID-19. However, the country’s health secretary later denied that it was never considered by the government.
What is herd immunity?
In group or herd immunity a population is protected from an infectious disease when it is immune from the virus either thorough vaccination or by developing antibodies.
The term is used to calculate the number people who would need to be vaccinated.
When more and more people become immune to the infection, they act as buffers between those who could spread the virus and those who are most vulnerable, such as;
- older adults
- young children
- pregnant women
- people with weakened immune systems
- people with certain health conditions
Eventually, the spread of the virus slows down and the chain of infection is broken.
Herd immunity happens when so many people in a community become immune to an infectious disease that it stops the disease from spreading.
This can happen in two ways:
- Many people contract the disease and in time build up an immune response to it (natural immunity).
- Many people are vaccinated against the disease to achieve immunity.
What is natural Immunity?
Natural immunity occurs when you become immune to a specific disease after contracting it. This triggers your immune system to make antibodies against the germ causing the infection inside of you. Antibodies are like special bodyguards that only recognize certain germs.
If you contract it again, the antibodies that dealt with the germ before can attack it before it spreads and makes you ill. For example, if you had chickenpox as a child, you most likely won’t get it again, even if you’re around someone with it.
Natural immunity can help create herd immunity, but it doesn’t work as well as vaccinations. There are several reasons for this:
- Everyone would have to contract the illness once to become immune.
- Contracting an illness can have health risks, sometimes serious.
- You may not know if you’ve contracted the illness or if you’re immune to it.
Will it work in Pakistan?
Since COVID-19 still does not have a vaccine, this could be dangerous gamble, says experts.
Gideon Meyerowitz-Katz, an epidemiologist working in chronic disease in Sydney, Australia, recently wrote in the Science Alert that 70 per cent of the entire population would have to be immune from COVID-19 to stop it from spreading.
He further adds that if coronavirus’s fatality rate is around 0.5 to 1 per cent, and if “70 per cent of an entire population gets sick, that means that between 0.35-0.7 per cent of everyone in a country could die, which is a catastrophic outcome.”
“Also 10 per cent of all infections will need to be hospitalized,” he said, which means more pressure on the country’s healthcare system.
“Humans are not herds”: WHO
The World Health Organistaion (WHO) has called the concept very “dangerous” for the pandemic.
Dr Michael Ryan, the executive director of the WHO’s health emergencies programme, recently told reporters in a press briefing that “humans are not herds and the concept of herd immunity is generally reserved for calculating how many people will need to be vaccinated in order to generate that effect.”
He added that this idea that “maybe countries who had lax measures and haven’t done anything will all of a sudden magically reach some herd immunity and so what if we lose a few old people along the way? This is a really dangerous, dangerous calculation.”
Dr Ryan said that this thinking could lead to a “brutal arithmetic.” This, he stressed, is a serious disease. “This is public enemy number one.”