There would be involved in antigen, antibody, immune system, cytokine, complement system, immune response, allergy, anti-infectionimmunity, immunological prevention and technology, and so on.
Recovery from infection by one provides lifelong immunity against that virus but confers only partial and transient protection against subsequent infection by the other three viruses.
感染一种病毒并恢复后，对该病毒具有终生免疫，但对此后感染的其他三种病毒只有部分和短暂免疫力。
3
The number of yellow fever cases has increased over the past two decades due to declining population immunity to infection, deforestation, urbanization, population movements and climate change.