It’s still possible to transmit Covid even if you are immune to virus

A new study led by Public Health England (PHE) gives early warning that some people with existing Covid immunity can still carry high levels of the virus and could theoretically transmit it.

Susan Hopkins, senior medical adviser at PHE and co-leader of the study has highlighted this possibility.

“We found people with very high amounts of virus in their nose and throat swabs that would easily be in the range which would cause levels of transmission to other individuals.”

Hopkins stressed the need for people who had previously caught Covid-19 and recovered to obey social distancing rules, wear masks and observe hygiene to avoid transmitting the disease. On this basis, a relaxation of lockdown would be a long time coming.

However, another report, known as the Siren study, is more optimistic. Dr Simon Clarke, Associate Professor in Cellular Microbiology at the University of Reading, says, “The Siren 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 reinfection of Covid is 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.”

He also give us an idea of what the conditions should be for release of lockdown. “The concerning finding is that some people who have Covid antibodies (from an infection) appear to still be able to carry the coronavirus and could spread it to others. 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,” he said.

Lawrence Young, Virologist and Professor of Molecular Oncology at Warwick Medical School added that because the results cover the months before the new variant took hold, “it will be important to determine whether previous infection with the old virus variant is able to offer protection from re-infection with the new virus variant”.

Recent reports suggest not all vaccines will be equally effective the latest variants, but we must keep a sense of perspective. Professor Sarah Gilbert, a pioneer of the Oxford-AstraZeneca vaccine, states that they may have a reduction in efficacy against mild to moderate disease and may not reduce the total number of Covid cases.

We must remember, she says, they’ll still offer protection against severe disease, hospitalisation and death.