Having virus ‘as good as a jab for our immunity’

SURVIVING coronavirus gives as much protection against future infection as vaccination, a major study revealed yesterday.

Public Health England researchers found prior Covid infection cut the chances of falling ill with the virus in the next five months by up to 94 per cent.

The scientists – led by key Government adviser Professor Susan Hopkins – said protection was ‘at least as good’ as that given by vaccines.

They were also confident immunity would last significantly longer than the five months in which participants were followed.

The researchers cautioned that a minority of survivors may contract and potentially transmit the virus without knowing it.

The research involved tracking 6,600 NHS staff who had been infected with Covid.

They had an 83 per cent lower chance than someone who had never had the virus of being reinfected within five months.

But most of those who were reinfected suffered no symptoms – meaning those who had been infected in the past had a 94 per cent lower chance of contracting the virus and falling ill with it.

In comparison, the Pfizer vaccine trials resulted in 95 per cent protection after two months – a figure that will have fallen by five months – and the Oxford jab is thought to provide 70 per cent protection.

Professor Hopkins said: ‘This study has given us the clearest picture to date of the nature of antibody protection against Covid-19.

‘Prior infection looks as good as vaccines, at least at this time interval, which is very good news for the population, and it will help alongside vaccines to give a level of immunity in the population that will start to reduce transmission.’

She added some who were reinfected had very high viral loads – whether or not they experienced symptoms – suggesting that they could pass it on to others. But she stressed that this only occurred in a minority and the risk of passing it on remains small.

‘Even if you are infectious you are likely to remain infectious for a very short time,’ she said, adding that the immune system learns to clear the virus from the body rapidly.

But she warned: ‘This protection is not total and we do not yet know how long protection lasts.

‘Even if you believe you already had the disease and are protected, you can be reassured it is highly unlikely you will develop severe infections, but there is still a risk you could acquire an infection and transmit to others.

‘Now more than ever it is vital we all stay at home to protect our health service and save lives.’

Professor Lawrence Young, a virologist at Warwick Medical School, said last night: ‘It will be interesting to know the degree to which previously infected individuals who are subsequently vaccinated are susceptible to reinfection – it could be that these individuals have an even longer-lived protective immune response.

‘The study took place before the UK virus variant took hold so it will be important to determine whether previous infection with the old virus variant is able to offer protection from reinfection with the new variant.’

Dr Simon Clarke, of the University of Reading, said: ‘The study has major implications for how we can get out of the current crisis.

‘The good news is that this study gives further weight that reinfections of Covid are rare, at least at this stage, and that having antibodies will provide protection for a meaningful amount of time, although it may not be lifelong immunity.

‘The concerning finding is that some people who have Covid antibodies appear to still be able to carry the coronavirus and could spread it.

‘This means that the vast majority of the population will either need to have natural immunity or have been immunised for us to fully lift restrictions on our lives, unless we are prepared to see many more people being infected and dying from Covid-19.’

‘This protection is not total’