Praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Hajj is an obligation upon every responsible able Muslim. Ability, here, is either being able to perform Hajj himself or delegate another to do it on his behalf. The former includes physical and financial capability and that it is safe to travel to Makkah.
It is stated in the Shafie book {Umdat As-Salik, P.122}, "An able person is one who is either able to perform Hajj himself or delegate another to perform it on his behalf. The first type requires physical as well as financial ability and that it is safe to travel to Makkah.
As for the ability to delegate another person to perform Hajj on one`s behalf, it is a condition that the person on whose behalf Hajj will be performed is unable to perform it himself i.e. deceased or has a physical disability.
An-Nawawi said, " It is a condition that the person on whose behalf Hajj will be performed is unable to perform it himself i.e. deceased, suffers a broken body part, has a chronic disease or of old age." {V.3:12}.
Consequently, if the official authorities prevented a person from performing Hajj due to the spread of diseases or not meeting the age requirement , then such person doesn`t meet the conditions of ability mentioned in Chapter Al-Emran, verse 97. In this verse, Allah says {what means}, " In it are Signs Manifest; (for example), the Station of Abraham; whoever enters it attains security; Pilgrimage thereto is a duty men owe to God,- those who can afford the journey; but if any deny faith, God stands not in need of any of His creatures." It isn`t permissible for the responsible able (Physically and financially) Muslim to delegate someone else to perform Hajj on his behalf because it is conditioned that the person on whose behalf Hajj will be performed is deceased or physically disabled.
In conclusion, it isn`t permissible for the responsible able (Physically and financially) Muslim to delegate someone else to perform Hajj on his behalf. And Allah the Almighty knows best.