A study carried out by Microbiologists at St George’s Hospital, using test data from South West London Pathology (SWLP) laboratories, shows that patients with laboratory evidence of Covid-19 in the first wave of the pandemic were 94% protected against reinfection in the second wave.
The team looked at the laboratory records of 66,001 patients between March and December 2020 and of the 10,727 patients who were infected during the first wave (between February and July 2020), as shown by either by a positive Covid-19 PCR test or a positive antibody test, only eight were re-infected during the second wave (August to December).
This research supports findings from the SIREN study released this week (14 January 2021), which found that previous infection provides 83% protection from reinfection for at least five months. However, researchers from both studies have warned that reinfection is possible and that even those with antibody protection could transmit the virus to others.
The results used for the research came from the SWLP microbiology laboratories, based at St George’s Hospital in Tooting, which serve four hospitals and a population of 1.3 million across south west London. The service is currently running over 1,000 tests a day from patients and staff across the four hospitals and this number is set to increase over the coming months.
Dr. Aodhán Breathnach, a microbiologist at St George’s Hospital who designed the study, says “The overall message coming from the research is a rare bit of good news, which we desperately need in these difficult times. We now know that patients who are infected by the virus do have a high level of protection from the virus for many months.”
We still need to be careful, because immunity may decrease with time, but I am hopeful that this study and other similar work such as SIREN are small steps on the road back to normality”