Disease Control Achieved through Herd Immunity
By leveraging the power of vaccines and the subsequent establishment of herd immunity, numerous diseases have been successfully brought under control. Among the diseases that have witnessed significant containment are pertussis, diphtheria, rubella, chickenpox, mumps, pneumococcal disease, rotavirus, Haemophilus influenza type b (Hib), hepatitis A, hepatitis B, influenza, polio, and tetanus. While some of these vaccines are administered to children during their developmental stages, others, such as the flu shot, necessitate annual administration to sustain the effectiveness of herd immunity.
Ineffective Herd Immunity
Understanding the concept of herd immunity is crucial in the fight against infectious diseases. The effectiveness of herd immunity depends on various factors, including the specific disease in question. It is important to note that herd immunity only applies to diseases that can be transmitted from person to person.
Take measles, for example. This highly contagious disease requires a high percentage of the population, more than 90 percent, to be vaccinated in order to achieve herd immunity. This means that if less than 90 percent of the population is vaccinated, the disease can still easily spread from person to person, making herd immunity ineffective in controlling its transmission.
On the other hand, diseases like polio are less contagious compared to measles. In the case of polio, establishing effective herd immunity requires vaccinating more than 80 percent of the population. This is because the disease is not as easily transmitted as measles, so a slightly lower vaccination rate can still prevent its widespread outbreak.
Therefore, the percentage of people that need to be vaccinated for herd immunity to work varies depending on the specific disease and its level of contagiousness. By understanding these factors, we can better appreciate the importance of achieving high vaccination rates in order to effectively protect the population against preventable diseases.