This particular vaccine is important because the natural infection doesnot confer lifelong immunity:

The statement indicates the significance of the vaccine, particularly in the context of certain infections that do not provide lifelong immunity after natural infection. This scenario is relevant in the case of diseases like influenza, pertussis (whooping cough), and various strains of coronaviruses, among others.

1. Natural Immunity vs. Vaccine-Induced Immunity: Natural immunity may wane over time, due to factors such as viral mutation and the immune system's memory duration. Vaccines are designed to mimic the pathogen and create an immune response, often with enhanced durability compared to natural infection.

2. Public Health Implications: Vaccines play a crucial role in controlling outbreaks and protecting individuals, especially those who are susceptible, such as the elderly or immunocompromised.

3. Preventing Disease Spread: By receiving a vaccine, individuals can reduce the likelihood of transmission within communities, contributing to herd immunity.

4. Adapting to Variability: Vaccines can be updated or modified to respond to changes in pathogens, ensuring ongoing protection against new strains that might evade natural immunity.

Overall, the development and administration of vaccines become paramount in safeguarding public health, particularly for infections where natural immunity is not lifelong, thus preventing the resurgence of diseases and enhancing overall community resilience.