Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the correct order to form a meaningful and coherent paragraph.

A. Research is ongoing to answer this question.

B. COVID vaccines have only been developed in the past few months, therefore it’s too early to say how long the COVID-19 vaccines will protect us.

C. The fact is we’re still learning how strong this protection is, and how long it lasts.

D. However, it’s encouraging that available data suggest that most people who recover from COVID-19 develop an immune response that provides at least some period of protection against reinfection.