Wa`alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother in Islam, thanks for your important question. We earnestly implore Allah to protect all people from diseases and help all Muslims to worship Allah and carry out their ordained duties easily.
Indeed, Islam has preceded all man-made laws in establishing rules for the protection of man. An infected Muslim should first seek treatment; it is haram (prohibited) for him or her to go to Hajj this year because this can lead to harming other pilgrims. It is also prohibited to falsify a certificate that he or she is free of this disease, as this, too, would inevitably lead to harming others, which is categorically forbidden in the Qur'an: (And those who hurt believing men and believing women undeservedly, they bear the guilt of slander and manifest sin) (Al-Ahzab 33:58).
In his response to your question, Dr. Muzammil H. Siddiqi, president of the Fiqh Council of North America, states:
It is haram for a person who has a dangerous infection to go to Hajj because this person might endanger the life and health of other people.
This person should consult doctors and take their advice seriously. He or she should postpone the Hajj until he or she becomes healthy and then go to Hajj.
Hajj is only obligatory on those who are healthy enough to undertake this journey and have enough means to provide for their journey.