Children may still have potential to spread coronavirus even if antibodies are detected, warns study
Many questions currently remain around how Covid-19 impacts children, their role in transmission and how long it takes them to clear the virus from their systems. Researchers have now found that the coronavirus and antibodies can coexist in young patients. According to the investigators, with most viruses, when one starts to detect antibodies, the virus is not detected anymore. But with Covid-19, they saw both. This suggests that children still have the potential to transmit the coronavirus even if antibodies are detected, says Dr Burak Bahar, lead author of the study and director of Laboratory Informatics at Children’s National Hospital, US.
“The results for this study showed us that the presence of antibodies alone might not be adequate to call a patient cleared from the virus. In addition, some age groups require a longer time to be tested negative for the virus. The findings add to the growing body of research studying how kids are impacted by the virus and the role they play in the spread of the virus,” Dr Bahar told MEA WorldWide (MEAWW).
Dr Bahar says the next phase of research will be to test if the virus that is present alongside the antibodies can be transmitted to other people. It also remains unknown if antibodies correlate with immunity, and how long antibodies and potential protection from reinfection last, she adds.
Antibodies are proteins that help fight off infections and can protect against getting that disease again (immunity). According to the US Centers for Disease Control and Prevention (CDC), antibodies are disease-specific. For example, measles antibodies will protect a person from getting measles if they are exposed to it again, but they will protect someone from getting mumps if they are exposed to mumps. In the case of Covid-19, there is currently no evidence that people who have recovered and have antibodies are protected from a second infection.
The team also includes experts from the George Washington University Health Sciences, US. They used a retrospective analysis of 6,369 children tested for SARS-CoV-2, the virus that causes Covid-19, and 215 patients who underwent antibody testing at Children’s National between March 13, 2020, and June 21, 2020. They found that children can have Covid-19 antibodies and the virus in their system simultaneously. Out of the 215 patients, 33 had co-testing for both the virus and antibodies during their disease course. Nine of the 33 showed the presence of antibodies in their blood while also later testing positive for the virus, reveals the analysis published in the Journal of Pediatrics.
The study also assessed the timing of viral clearance and immunologic response. It found the median time from viral positivity to negativity, when the virus can no longer be detected, was 25 days. “The median time to seropositivity, or the presence of antibodies in the blood, was 18 days, while the median time to reach adequate levels of neutralizing antibodies was 36 days. Neutralizing antibodies are important in potentially protecting a person from re-infection of the same virus,” the findings state.
The authors also found that patients aged 6 through 15 years old took a longer time to clear the virus (median of 32 days) compared to patients 16 through 22 years old (median of 18 days). Females in the 6-15 age group also took longer to clear the virus than males -- a median of 44 days for females compared to a median of 25.5 days for males.
According to Dr Bahar, the takeaway from the study is that people cannot let their guard down just because a child has antibodies or is no longer showing symptoms. “Our findings are one more piece of a very complicated puzzle. But each piece is critical for developing policies to slow the rate of viral transmission in our community. We must remain diligent about good hand hygiene, social distancing, and wearing a mask,” she recommends.