I’m loving my fellow human beings right now but I’m hating them a bit too. The woman at the supermarket who leaned right over me to get at a bag of crisps. Hate. The Spitfire and Hurricane doing a flypast for Captain Tom Moore’s 100th birthday. Love. The deep-seated, long-standing, persistent prejudice against minorities that the coronavirus crisis is highlighting. Hate. Hate. Hate.

The best way to explain what I mean is by telling you the stories of some of the people who’ve been at the receiving end of the prejudice. People like Dij. I spoke to Dij while he was a student at Glasgow University. He told me about the shock of learning that his mother had cancer. Later, while she was in hospital, she developed an infection and needed a blood transfusion to save her life. Dij, obviously, wanted to help.

But as far as the authorities were concerned, there was a problem with Dij and his offer. "I went along to my local clinic on my 17th birthday,” Dij told me. “I really wanted to give blood. After I'd handed in my questionnaire, I was very sensitively taken to the side by the nurse who said: 'I'm really sorry, we're really grateful to have you along but unfortunately because you have engaged in sexual activity with men, we can't take your blood'."

Dij thought things might be different when his own mother was ill, but no. “They asked my uncles, my brother, all of her work colleagues if they would be willing to see if they would be a match and I said, can I be tested?” But the rule still stood: Dij could not donate. “It's especially poignant when it's a member of your own family,” he said. “I would love to help, but you know what? I can't – you don't want my blood.”

Exactly the same thing is happening with coronavirus: gay men want to help by donating their blood but they’re being told no. Men like Andy Roberts. Mr Roberts heard about a trial being conducted at St Guy’s and Thomas’ hospital in London that will collect the plasma of Covid patients, the hope being that the plasma can be used to help people who aren’t producing enough antibodies to fight the virus. Mr Roberts, who’s had the virus, called up to volunteer, but at the end of a 20-minute conversation, he was asked about his sexuality. He was then told he could not donate.

A few things will probably occur to any reasonable person when they hear that story. First, why wait until the end of a 20-minute conversation before asking about the person’s sexuality? What a waste of time. Second, what’s to stop people lying about themselves during the health and lifestyle check so they can donate blood? Indeed, the BBC has uncovered evidence that is exactly what’s happening in some cases: some gay men donate blood by failing to admit their sexuality. And third, after so much has changed for the better, why on earth is there still a ban on gay men donating blood anyway?

The answer, I’m afraid, lies in some pretty age-old prejudices and stereotypes about sex and gay men. There are still many who believe homosexuals are more promiscuous and reckless in their sex lives even though gay men behave in vastly different ways just like straight men do. The UK is also still living in the long shadow, even now, of the idea that Aids was a gay disease. Andy Roberts’ partner Keith puts it this way: in the UK being gay is still thought of as a form of contamination.

Ah, but surely it’s about the science isn’t it? Not really. The screening of blood has improved dramatically since the height of Aids 30 years ago which means the risk of contamination is extremely low – it isn’t zero, but then it isn’t with straight people either. Also, what’s deeply unscientific, and prejudiced, is that straight people do not face the same level of scrutiny, which leads to the farce of turning down donations from gay men in long-term relationships, like Dij and Andy, while accepting donations from sexually promiscuous heterosexuals.

Since prejudice is a preconceived opinion based on a negative instinct rather than reason and then applied indiscriminately to a group, the answer is to treat people, gay and straight, like individuals, and thankfully some countries are already doing it. If you want to donate blood in Italy for example, you will be assessed individually according to your particular lifestyle and behaviour. This is reasonable. In Italy, Dij and Andy would have been able to donate their blood.

By contrast, the compromise that’s been reached in the UK in the last few years is that gay men can donate blood but only if they haven’t had sex in the previous three months, which also buys into the old familiar prejudices. A gay man who doesn’t have sex is a “good gay” and one that does have sex is dirty and contaminated and not be to be trusted. It’s an unreliable word but sometimes it’s the only one that will do: homophobia.

Obviously, homophobia is not new, but it often takes a crisis like coronavirus to underline it and highlight it – hopefully, the crisis can also underline how irrational and irresponsible it is. Our collective response to the virus relies largely on people behaving in a selfless way – by staying at home, or working in hospitals, or doing the shopping for their neighbours who can’t get out – and our recovery from the virus will rely on the same selflessness.

So why exclude gay men from one of the important ways they can take part? Donations of blood have dropped in recent weeks, probably because people are worried about going to a clinic during the Covid outbreak. Fresh donations are badly needed. And yet one group is effectively banned from helping. Not only is this unscientific, it’s unfair, and prejudiced and I think it rather highlights the difference between the unthinking virus and the people it infects, who should know better. It’s sometimes said the virus doesn’t discriminate. If only the same could be said of humans.