The first care package I received from home was a few months into my first year of university in the US. I was 17 and it was my first time living alone abroad; homesickness came in waves and sat like a dead weight on my chest. So when the brown cardboard box came, battered from its flight from China, I tore into it as if it were a lifeline.

Nestled among the bubble wrap were mementos of the life I had left behind: beef jerky from the convenience store at the corner of our street, a small tin of green tea from our last family hike to a mountain plantation, a dog-eared Polaroid of my best friend and me that sat on my nightstand at home. It was a tug on the invisible thread that still tethered me to those who were thinking of me; a reminder that despite my immediate loneliness I was not, in fact, alone.

These days, as the coronavirus nudges us towards a hermetically sealed world, people are receiving care packages of a different kind. Face masks, hand sanitiser and protective gear have replaced childhood trinkets, forgotten items of clothing and obscurely named local snacks. Friends and relatives in China with loved ones overseas now pair their homemade sentiments with pandemic survival essentials: hand-knitted baby clothes packed with protective gloves, boxes of cold medicine tucked under stacks of postcards, a roll of toilet paper playfully cradled among face masks in a shoe box.

It’s a stunning reversal of the trajectory of misfortune. Just a month earlier families overseas were sending those same supplies to loved ones in China as the country buckled under the weight of Covid-19.

My dad, who turns 70 next month, has been living alone in Beijing since the pandemic halted the city and the nation. Last week he made his first trip out of self-isolation in two months. He drove to a DHL warehouse on the outskirts of the city after reading that they were offering a discount on “coronavirus care packages” to Australia and other affected countries. He had saved up a small box of face masks during the lockdown and wanted to mail them to me – now that Australia is grappling to contain the virus. “Maybe you can share it with your friends and colleagues, since there’s a shortage now overseas,” he later told me.

The ties that bind us can never be sanded down by crisis or catastrophe, only welded tighter

He stood for more than an hour in a parking lot with scattered groups of patrons – parents, grandparents, sons and daughters – all waiting to send warmth in the form of medical supplies to their relatives overseas. One couple was sending a few masks to a daughter studying in the UK, another was mailing protective gear to a son who works at a hospital in Germany. My dad told me it was clear everyone was trying to negotiate this brave new world of uncertainty. The pleasantries had changed: which pharmacy did you buy your masks from? Should I be sending my grandkids the surgical mask or the N95? How do you tell which quality is better?

It seemed everyone had emerged from the claustrophobia of isolation imbued with a renewed sense of purpose – after watching as the virus spread across the globe – and an understanding that there were people out there who depended on them. They were all determined to tug on the invisible thread that still connected us.

Seeing an elderly couple standing to the side, my dad asked them what they were there for. The man said they had come to send some face masks back to their daughter in the US, unused ones their daughter had sent them just two months ago when China’s infections were surging.

“We tried not to use them all,” he said. “I had hoped to keep one for when this is all over, as a reminder of what we’ve been through. But now looking at what’s happening in the US, I figured I better send them back to my daughter. They need them more than us now.”

It’s been repeatedly said that the world has been changed by the coronavirus, that we will carry the scars of this tragedy for decades. But this existential moment of reckoning also reminds me of a quote from Charles Dickens’ Great Expectations, when Estella speaks of the lessons suffering teaches us: “I have been bent and broken, but – I hope – into a better shape.”

I imagine my dad standing with those families in that parking lot and the countless families around the world with loved ones separated by oceans, fences and even glass. People who choose to spend fleeting moments of their freedom from quarantine to send care packages and remind their families that there is someone thinking of them; that despite the social distancing, the shuttered cities and borders, they still matter to someone. It’s a heartening sign that perhaps the ties that bind us can never be sanded down by crisis or catastrophe, only welded tighter.

So when my coronavirus care package eventually arrives I will tear into it with the same joy as I did when I received my first one at university. The contents may have changed but the affection they convey remains as potent as ever.

• Yang Tian works as a news producer at Guardian Australia