What does the cryptic crossword clue "Deadly virus hard to shift around centre of Vienna (6)" mean?

The wordplay uses an anagram. anagram of EN (synonym="EN") + HARD (synonym="HARD") = HENDRA The answer is HENDRA.

Deadly virus hard to shift around centre of Vienna (6)

Independent Cryptic #11634 | 2 Down | 2024-01-24 flower