Washington,  The surge in Delta variant cases in the US has also fuelled misinformation regarding vaccines in social media, increasing vaccine hesitancy, media reports said.

According to Zignal Labs, which tracks mentions of phrases on social media and by news outlets, phrases prone to vaccine misinformation spiked in July as much as five times from June, The New York Times reported on Tuesday.

These include: vaccines don't work (up 437 per cent), contain microchips (up 156 per cent), people should rely on their "natural immunity" instead of getting vaccinated (up 111 per cent) and cause miscarriages (up 75 per cent).

These claims dipped in May and June when Covid cases plummeted, but with infections soaring due to the Delta variant, the volume of misinformation is also surging, the report said.

"These narratives are so embedded that people can keep on pushing these anti-vaccine stories with every new variant that's going to come up," Rachel E. Moran, a researcher at the University of Washington, was quoted as saying.

"We're seeing it with Delta, and we're going to see it with whatever comes next," she added.

Further, the efforts by social media platforms to crack down on misinformation about the virus have also not succeeded.

Facebook said that it removed confirmed violations of its coronavirus misinformation policy from comments, and that it had connected people with authoritative information about the virus.

Meanwhile, Russian-aligned disinformation campaigns are also contributing to the spread of falsehoods, the NYT reported last week. The campaigns have spread fake information about side effects of the Covid vaccines developed by Pfizer/BioNTech and Moderna, and even stated that the Biden administration will force people to get vaccinated.

According to Moran, the coronavirus misinformation will not go away anytime soon. "Unfortunately it's not spikes and troughs, but steady levels of misinformation," she said.

With "about 93 million people" not vaccinated against Covid-19 in the US, the claims may likely hamper efforts to increase inoculation rates, thus increasing the number of infections.

The vast majority of people testing positive for the virus in recent weeks, and nearly all of those hospitalised from the coronavirus, were unvaccinated. Public health experts, as well as doctors and nurses treating the patients, say misinformation is leading to some of the vaccine hesitancy, the NYT reported.