Which therapy can be used to treat the genetic disorder $S.C.I.D.$?

$ELISA$ is based on:

Statement-$I$: In vitro fertilisation leading to a test tube baby is a part of biotechnology.
Statement-$II$: Developing a $\text{DNA}$ vaccine is a part of biotechnology.

At present,about . . . . . . recombinant therapeutics have been approved for human use,the world over.

Which of the following is/are correct about Adenosine Deaminase $(ADA)$ deficiency?
$I$. In the absence of adenosine deaminase enzyme,purine metabolism is disturbed and $T$-lymphocytes fail to function.
$II$. $ADA$ deficiency is caused by the deletion of the gene for $ADA$.
$III$. In some cases,it can be cured by bone marrow transplantation and enzyme replacement therapy. But in both approaches,the patients are not completely cured.
$IV$. For permanent cure,genes isolated from the bone marrow cells producing $ADA$ at early embryonic stages can be a possible cure.
Which of the above statements are correct?

Name a recombinant vaccine that is currently being used in a vaccination program.