As the coronavirus pandemic continues to take a heavy toll on the world’s population, scientists are seeking to determine the protective effect of previous infection with the coronavirus, and a new study published in BMC Medicine concludes that, at least with prevalent variables, the risk of contracting the virus again among unvaccinated people decreases by 80% or more.
More cases of reinfection are reported with an average interval of more than 100 days between the first and second infection, however, several researchers have shown neutralizing antibodies to the virus for nine months or more and their ability to prevent re-infection.
One study in the UK examined 12,000 health care workers (HCW) monitored for 6 months, which showed a reduced risk of contracting the virus in nasopharyngeal swabs.
The current study, published in news-medical, looks at both recurrence rates and symptoms for COVID-19 among participants based on baseline detection of antibodies.
What did the study show?
The researchers conducted the study in Switzerland, studying about 4,800 cases, and the participants were followed for about 8 months, at baseline, 3% of the participants, or 144, had antibodies to the virus.
All symptomatic participants were followed up in approximately 24 (median) questionnaires until vaccination, over 5,300 swabs were performed, both tests showed similar accuracy, but the mean number of swabs was lower among sera versus negative individuals, at 47% and 57%, respectively. At least one positive smear was tested during the follow-up period in 550 participants.
The study suggested that while 80% of people with antibodies were protected from infection at six months, effectiveness waned to 47% of older adults (65 years and older).
As the coronavirus pandemic continues to take a heavy toll on the world’s population, scientists are seeking to determine the protective effect of previous infection with the coronavirus, and a new study published in BMC Medicine concludes that, at least with prevalent variables, the risk of contracting the virus again among unvaccinated people decreases by 80% or more.
More cases of reinfection are reported with an average interval of more than 100 days between the first and second infection, however, several researchers have shown neutralizing antibodies to the virus for nine months or more and their ability to prevent re-infection.
One study in the UK examined 12,000 health care workers (HCW) monitored for 6 months, which showed a reduced risk of contracting the virus in nasopharyngeal swabs.
The current study, published in news-medical, looks at both recurrence rates and symptoms for COVID-19 among participants based on baseline detection of antibodies.
What did the study show?
The researchers conducted the study in Switzerland, studying about 4,800 cases, and the participants were followed for about 8 months, at baseline, 3% of the participants, or 144, had antibodies to the virus.
All symptomatic participants were followed up in approximately 24 (median) questionnaires until vaccination, over 5,300 swabs were performed, both tests showed similar accuracy, but the mean number of swabs was lower among sera versus negative individuals, at 47% and 57%, respectively. At least one positive smear was tested during the follow-up period in 550 participants.
The study suggested that while 80% of people with antibodies were protected from infection at six months, effectiveness waned to 47% of older adults (65 years and older).