Students will miss out on Canterbury University's Tea Party and Lincoln University's Garden Party.
Both events, due to take place this month, were unable to meet the vaccine certificate requirement for large-scale events.
University of Canterbury Student Association president Kim Fowler said students do understand this is the best decision to keep them safe.
"Students are obviously disappointed. It was going to be a big event and in these times it just wouldn't be right to host it.
"The guidance from the Government is that in some time, we can hold these events when we're all vaccinated so we're just encouraging everyone to get vaccinated for summer," she said.
Lincoln University Student Association president Gregory Fleming said it is disappointing but it's not surprising.
He said it comes down to safety and people are aware nothing is guaranteed during Delta.
Many events in the Canterbury region are at risk with a decision on whether the public will be allowed to attend Addington Cup Week expected on October 19.
Other options for how the Canterbury A&P Show might go ahead are also being discussed.
