The study found that if 75% of the population is vaccinated, effectiveness must be 80% to stop an ongoing epidemic.
Researchers at the City University of New York have developed a computer simulation model to predict how effective a vaccine needs to be to contain the Covid-19 pandemic. The results were published in July in the American Journal of Preventive Medicine.
According to the research, if 75% of the population is vaccinated, the vaccine must be at least 70% effective to prevent an epidemic and 80% to extinguish an ongoing epidemic.
If only 60% of the population is vaccinated, the vaccine would need to be at least 80% effective to prevent an epidemic and 100% effective to extinguish an ongoing epidemic.
“Some are pushing for a vaccine to come out as quickly as possible so that life can ‘return to normal’,” said Bruce Y. Lee, the study’s leader. “However, we have to set appropriate expectations. Just because a vaccine comes out doesn’t mean you can go back to life as it was before the pandemic.”
The researchers hope the study’s results will be useful to other scientists and help to define the expectations of public policy-makers, business leaders, and the general public about the pandemic.
“It is important to remember that a vaccine is like many other products,” Lee said. “What matters is not just that a product is available, but also how effective it is.”