Reinfection

Subject: Science and tech

Context:

Centers for Disease Control (CDC) in the United States acknowledge that there had been instances in which people had tested positive again after having recovered from the disease once.

Concept:

• It could be because of what it described as “persistent viral shedding”.
• Recovered patients can have low levels of virus for up to three months after the infection, and though it is no longer enough to make the person sick or transmit the disease to others, it can get detected in diagnostic tests.
• These first cases of reinfection show that the immunity developed after contracting the disease once may not be long-lasting, and the virus could continue to circulate in the populations even after levels of community-wide immunity, either through natural infection or by vaccination, are reached.
• It has also triggered concerns about the effectiveness of vaccines being developed for the infection.