Initially when the coronavirus that causes COVID-19 started to spread, virtually no person was immune. In absence of resistance, the virus spread quickly across communities. But how can get to the point of stopping it?
Concept of herd immunity
When a large percentage of the population is immune to an infectious disease, it provides indirect protection – or what is referred to as herd immunity to those not immune to the disease.
For example, considering that 80% population is immune, 4 out of 5 people who encounter with an infected person will not become sick. This leads to control over spread of the virus. Depending on how contagious the virus is, an average of 70-90% of population would need to be immune to achieve herd immunity.
— MI6 Rogue 🇬🇧 (@mi6rogue) May 15, 2020
However, for infections that do not have a vaccine yet, even if adults are able to develop immunity owing to a prior infection, the infection may still affect children and those with a weak immune system.
Next few months with COVID-19
While the scientists work tirelessly towards development of a vaccine, measures must be put in place to prevent explosive outbreaks like those observed in places like New York city. The death rate of COVID-19 remains unknown, but the data suggests that is 10x that of the flu. It is higher among groups with a weaker immune system such as the elderly. Ending a pandemic quicker is not always better in case of pandemics with high mortality rates as was experienced in the 1918 Flu pandemic.
— Rob Abdul (@robabdul) May 17, 2020
The physical distancing guidelines that have been issued by the government may vary depending upon the region and other factors. But unless we want millions of people infected, life is unlikely to be completely “normal” until scientists are able to formulate and distribute a vaccine.