The World Health Organization (WHO) recommends routine vaccination only if a country can keep more than 80% of people vaccinated. If only 20% to 80% of people are vaccinated it is possible that more people will get the disease at an older age and outcomes overall may worsen.
The World Health Organization (WHO) suggests immunization as a regular practice only if a nation can maintain an immunization rate of over 80%. If the vaccination rate drops to between 20% and 80%, it may lead to more people contracting the disease at older ages, ultimately resulting in poorer health outcomes.