• Dr Alexander Chepurnov, 69, reinfected himself with Covid-19 as part of a test

  • His second infection was far more serious and required him to be hospitalised

  • He says hopes for herd immunity are futile due to antibodies falling rapidly

  • The Institute of Clinical and Experimental Medicine professor studies antibodies

Source: Daily Mail


PUBLISHED: 16:01, 28 October 2020 | UPDATED: 20:54, 28 October 2020

Reprinted for educational purposes and social benefit, not for profit.

A professor who in an experiment infected himself with Covid-19 to become ill with the virus for a second time says hopes for herd immunity are overblown.

Dr Alexander Chepurnov, 69, first caught coronavirus on a skiing trip to France in February.

After recovering back home in Siberia without requiring hospitalisation, he and his team at the Institute of Clinical and Experimental Medicine in Novosibirsk launched a study into coronavirus antibodies.

He said: ‘By the end of the third month from the moment I felt sick, the antibodies were no longer detected.

He decided to examine the probability of reinfection.

In the interests of science, Chepurnov became a human guinea pig and deliberately exposed himself to COVID-19 patients wearing no protection, he said.

He said: ‘My body’s defences fell exactly six months after I got the first infection. The first sign was a sore throat.’

His second infection was far more serious and he was hospitalised.

He said: ‘For five days, my temperature remained above 39C. I lost the sense of smell, my taste perception changed.

‘On the sixth day of the illness, the CT scan of the lungs was clear, and three days after the scan, the X-ray showed double pneumonia.’

‘The virus went away rather quickly. After two weeks it was no longer detected in the nasopharyngeal or in other samples.’

His conclusion based on his own case is that collective or herd immunity is a forlorn hope.

The virus is here to stay, and while vaccines may give immunity this is likely to be temporary.

He said: ‘We need a vaccine that can be used multiple times, a recombinant vaccine will not suit. Once injected with an adenoviral vector-based vaccine, we won’t be able to repeat it because the immunity against the adenoviral carrier will keep interfering.’

The professor formerly worked at State Research Vector Centre of Virology and Biotechnology in Siberia, makers of Russia’s second vaccine against Covid-19 known as EpiVacCorona which will require repeat injections to maintain immunity, say its proponents.

This followed the Sputnik V vaccine, now being given to essential workers.


Herd immunity is a form of indirect protection from infectious disease that occurs when a high percentage of a population has become immune to it, either through vaccination or previous infection.

To cause an outbreak, a virus must have a continuous supply of potential victims whose immune system do not know how to fend it off before it makes them ill.

When a virus or bacteria enters the body the immune system creates substances called antibodies, which are designed to destroy one specific type of bug.

People who have these antibodies normally enjoy long-term protection, or immunity, against an illness.

If nobody is immune to an illness – as was the case at the beginning of the coronavirus outbreak – it can spread like wildfire.

However, if, for example, half of people have developed immunity there are only half as many people the illness can spread to.

As more people become immune, the bug finds it harder to spread until its pool of victims becomes so small it can no longer spread at all.

The threshold for herd immunity is different for various illnesses, depending on how contagious they are – for measles, around 95 per cent of people must be vaccinated to it spreading.

For polio, which is less contagious, the threshold is about 80-85 per cent, according to the Oxford Vaccine Group.

Experts say herd immunity will only work for Covid-19 if about 60 to 70 per cent are immune.


Herd immunity is considered a controversial route for getting out of the pandemic because it implies encouraging the spread of the virus, rather than containing it.

When UK Government scientists discussed it in the early days of the pandemic, it was met with criticism and therein swept under the carpet.

The Chief Scientific Adviser Sir Patrick Vallance said at a press conference on March 12, designed to inform the public on the impending Covid-19 crisis: ‘Our aim is not to stop everyone getting it, you can’t do that. And it’s not desirable, because you want to get some immunity in the population. We need to have immunity to protect ourselves from this in the future.’

Sir Patrick has since apologised for the comments and said he didn’t mean that was the government’s plan.

In a Channel 4 documentary aired in June, Italy’s deputy health minister claimed Boris Johnson had told Italy that he wanted to pursue it.

The Cabinet Office denied the claims made in the documentary and said: ‘The Government has been very clear that herd immunity has never been our policy or goal.’