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Buckinghamshire Healthcare NHS Trust staff contribute to vital piece of COVID-19 jigsaw

Buckinghamshire Healthcare NHS Trust staff have played a vital role in an urgent Public Health England trial. The SIREN study, looking to understand how long people infected with COVID-19 in the past are likely to be protected against reinfection, published its interim analysis 12th January and found: 


  • Antibodies from past COVID-19 infection provide 83% protection against reinfection for at least 5 months;

  • Reinfections in people with antibodies were rare – experts identified 44 potential reinfections among 6,614 participants who showed evidence of previous infection;

  • However, early evidence also suggests a small number of people with antibodies may still be able to carry and transmit COVID-19.

  • Public Health England continues to stress the importance of following the stay at home rules and remembering hands, face, space - whether you have had the virus or not.


Thousands of health care workers across the UK, including hundreds at Buckinghamshire Healthcare NHS Trust have been regularly tested since June for new COVID-19 infections as well as the presence of antibodies, which suggest people have been infected before.


SIREN study leaders are clear this first report provides no evidence towards the antibody or other immune responses from COVID-19 vaccines, nor should any conclusions to be drawn on their effectiveness. The SIREN study will consider vaccine responses later this year.


PHE scientists working on the study have concluded naturally acquired immunity as a result of past infections provide 83% protection against reinfection, compared to people who have not had the disease before. This appears to last at least for five months from first becoming sick.


While the SIREN study will continue to assess whether protection may last for longer, this means people who contracted the disease in the first wave may now be vulnerable to catching it again.


PHE also warned that although those with antibodies have some protection from becoming ill with COVID-19 themselves, early evidence from the next stage of the study suggests that some of these individuals carry high levels of virus and could continue to transmit the virus to others.


It is therefore crucial that everyone continues to follow the rules and stays at home, even if they have previously had COVID-19, to prevent spreading the virus to others. Remember to wash hands regularly, wear face coverings and make space from others to help reduce the likelihood of passing on the virus.


It is vital that, with cases at their highest level to date and the R number above 1 across the country, people do everything that they can to avoid the risk of transmitting the virus to other people.


Professor Susan Hopkins, Senior Medical Advisor at Public Health England and the SIREN study lead said:


“This study has given us the clearest picture to date of the nature of antibody protection against COVID-19 but it is critical people do not misunderstand these early findings.


“We now know that most of those who have had the virus, and developed antibodies, are protected  from reinfection, but this is not total and we do not yet know how long protection lasts. Crucially, we believe people may still be able to pass the virus on.


“This means 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 that 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.


“We are immensely grateful to our colleagues in the NHS for giving up their time to volunteer, and whose continued participation at a time of great stress is making this research possible.”


Read the full interim analysis for the trial here


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