“Welcome to our first-ever virtual match celebration,” Dr. Lisa Mellman, associate dean for student affairs at Columbia Medical School, said to her Zoom camera on Friday.

Typically, she kicks off the ceremony in an auditorium filled with proud parents; this year, she faced a computer in a sterile office. “What an incredibly talented class this is,” she said to the screen. “They’re ready to be doctors, doctors who are needed more than ever in this global health crisis.”

This message was heard by medical students nationwide: Their work will be sorely needed. To many, this is both welcome and anxiety-inducing. They have grown used to feeling as if they are underfoot, asking technical questions while trying not to disturb the residents at work. Now, given the surge in hospital intakes as the coronavirus spreads, they see the essential role they will play in the medical work force.

With near-daily reports from medical providers that struggle with shortages of personal protective equipment, now is a particularly challenging time to enter the field.

“Our students are very excited about matching and being able to pursue their dreams,” Dr. Mellman said in an interview on Friday. “But I would not be true to all the different emotions without also acknowledging that there’s an anxiety that some students have about beginning work at this particular time.”

A grave sense of duty has already taken hold for some students. Kendall Kiser, a fourth-year student at McGovern Medical School in Houston, did a critical care rotation earlier in March at a local hospital and saw a patient admitted who was a possible coronavirus case. There were no known cases in the city at the time, and the attending physician “freaked out,” Mr. Kiser said.

For 24 hours the staff waited for the county to determine whether they could administer a test, as hospital administrators began to re-evaluate the number of intensive care beds that had been designated for Covid-19.