More than 60 per cent researchers faced negative experiences as a result of their media appearances or their social media comments about Covid-19 pandemic, revealed a survey conducted by science journal Nature.

About 22 per cent received threats of physical or sexual violence, while 15 per cent received death threats.

The findings are based on a self-selecting survey of 321 people working in fields relevant to Covid.

While six scientists said they were physically attacked, some were attacked indirectly -- their employer received complaints about them, or that their home address was revealed online, Nature reported.

Much abuse happens on social media, particularly on Twitter. Among the 63 per cent who used the microblogging site to comment on aspects of Covid, around one-third said they were "always" or "usually" attacked on the platform.

For such individuals, coping strategies include trying to ignore it, filtering and blocking e-mails and social-media trolls, or deleting their accounts.

"It is very harrowing if every day, you open up your e-mails, your Twitter, you get the death threats, you get abuse every single day, undermining your work," Andrew Hill, a pharmacologist at the University of Liverpool's Institute of Translational Medicine. Hill has deleted his Twitter account.

As a result, scientists who reported higher frequencies of trolling or personal attacks were also most likely to say that their experiences had greatly affected their willingness to speak to the media in the future.

"The more prominent you are, the more abuse you're going to get," historian Heidi Tworek at the University of British Columbia in Vancouver, Canada, was quoted as saying.

But researchers shouldn't try to cope on their own, she added, stating that there is much that institutions can do to assist scientists who are receiving abuse.

In the survey, 44 per cent of scientists who said they'd been trolled or experienced personal attacks said they never told their employer. Of those who did, however, almost 80 per cent found their employer "very" or "somewhat" supportive.

Although such coordinated social-media campaigns and threatening e-mails or phone calls to scientists are not new, but tied to the pandemic, the abuse was a new and unwelcome phenomenon.

"I believe national governments, funding agencies and scientific societies have not done enough to publicly defend scientists," one researcher wrote in their survey response.