"Here are the states that postponed their primaries due to coronavirus"on CNN politics.

Hi Ali, I have used both with and without THE in commonly spoken native English. It depends on whether it’s related to as a collective uncountable noun or a countable noun but I think it can be either. Your English wouldn’t sound incorrect with either. Alice

In conversational English, you would definitely need 'the' before conference or an article like 'a'. Before coronavirus it is a little more tricky. It's true you can omit 'the' before coronavirus, but it's implied. If I were to speak the second sentence aloud, I would barely make the sound to indicate 'the' and so it would sound like coronavirus without 'the', but native speakers know it's there. For formal English, you'd have to consult an English teacher. Cheers.

Hi :) Yes, the virus.

Hi Ali, I would say 'the coronavirus' because there are more than one coronaviruses but you are talking about a specific (the current) one. The illness you get as a result of being infected with it is called Covid-19 so you could say '...cancelled because of Covid-19' as this is a specific name which is of itself grammatically definite.