Residents undergo a free rapid nasopharyngeal antigen swab test for Covid-19 at a test center in a school gym on November 20, 2020 in Bolzano, South Tyrol, northern Italy.
PIERRE TEYSSOT | TBEN | Getty Images
LONDON – People who have contracted the coronavirus are “very unlikely” to contract the disease again for at least six months, according to a new study from Oxford.
The researchers say the results are “exciting” because they represent an important step in understanding how Covid-19 immunity works.
The study, published on Friday, claims to be the first large-scale research into protecting people from reinfection after contracting the coronavirus. It was part of a major collaboration between the University of Oxford and the Oxford University Hospitals NHS Foundation Trust but has not yet been peer reviewed.
This follows a string of encouraging vaccine results over the past two weeks following end-stage trial readings from Pfizer-BioNTech and Moderna, as well as positive phase two results from AstraZeneca-Oxford.
There is growing optimism that a Covid vaccine could help end the coronavirus pandemic that has claimed more than 1.3 million lives worldwide.
Public health officials and experts have warned that it could take months, or even more than a year, to distribute enough doses of any potential vaccine to achieve so-called herd immunity and suppress the virus.
‘Really good news’
The study covered a 30-week period between April and November with 12,180 healthcare workers employed at Oxford University Hospitals.
Workers were tested for antibodies against the virus that causes Covid-19 in order to detect who had previously been infected. They were tested for the disease when they were not feeling well with symptoms and as part of regular testing.
The results showed that 89 of the 11,052 staff members without antibodies developed a new infection with symptoms. However, none of the 1,246 staff with antibodies developed symptomatic infections. Staff with antibodies were also less likely to test positive for the virus without symptoms.
“This is really good news, because we can be sure that, at least in the short term, most people who contract COVID-19 will not have it again,” said Professor David Eyre of the Department of Oxford University’s Nuffield Population Health. .
In addition, the researchers said the opposite was also found to be true. Healthcare workers who did not have antibodies to Covid were more likely to develop the infection.
A paramedic takes a woman out of an ambulance outside Burgos Hospital in Burgos, northern Spain on October 21, 2020, the first day of a two-week lockdown in an attempt to limit contagion of the new coronavirus COVID-19 in the surface.
Cesar Manso | TBEN | Getty Images
The researchers said there was not yet enough data to make a judgment on protection against initial infection beyond a six-month period. The study will continue to collect data, in the hopes of verifying how long the protection against reinfection can last.
“This is an exciting discovery, indicating that infection with the virus provides at least short-term protection against re-infection – this news comes the same month as other encouraging news on COVID vaccines,” said said Dr Katie Jeffery, director of infection prevention and control for Oxford University Hospitals.
A previous study by staff at Oxford University Hospitals NHS Foundation Trust, published on November 5, found that anti-Covid-19 antibodies had dropped by half in less than 90 days.
This study, which has not yet been peer-reviewed, said antibody levels peak lower and drop faster in young adults.
“We know from a previous study that antibody levels decline over time,” Eyre said, referring to research published earlier this month.
“But this latest study shows that there is some immunity in those infected. We will continue to closely monitor this cohort of staff to see how long the protection lasts and whether the previous infection affects the severity of the infection if the people are infected again. “