My news feed is full of jubilant photos of doctors and nurses announcing their vaccinations. I consider taking my own photo, but then hesitate. Because just a few floors up, there are dozens of patients who cannot breathe, who are scared and alone, who might die simply because they shared a holiday dinner. I find myself, nine months into this pandemic, vaccinated and yet still on a pendulum swinging between hope and despair.

Outside, the snow falls. Already it feels like a long winter. Here in the hospital, the anxious adrenaline of the spring has given way to a heavy, lingering sadness. We are caring for patients who have sacrificed and taken precautions for months and now — bending under the pain of isolation, starved for human connection — might die simply because they decided to spend time indoors with people they love or to go out to dinner. I have been careful so long, they must have thought. Humans are inherently optimistic, notoriously bad at assessing risk. Surely this one small thing will be OK.

I recently cared for a man who loved Boston sports, whose wife had decided to have a quick meal with a friend. By the time she learned that her friend had symptoms of Covid-19, she had already passed the virus on to her husband. He died after weeks on a ventilator. There is a grandmother whose family took false comfort in a negative test. A father who welcomed a dozen people into his home for the holidays. Each casualty is made even more poignant by the celebratory vaccine selfies on my phone and the knowledge that had they waited, my patients might have lived.