Misc 12/01/2021

Covid-19 immunity lasts at least 8 months

The amount of antibodies and immune cells detected in recovered patients point to a protective immunity

Toni Pou
2 min
Tècnics d’un laboratori alemany en plena feina de detecció de casos positius de covid-19 en mostres.

BarcelonaSince the beginning of the pandemic, one of the questions that has been asked most often is how long the antibodies and cells that the immune system generates to protect the body from the virus last. "It takes time to know," the scientists said. And indeed, as months go by, the evolution of this immune response becomes better known. In November, it became known that the antibodies produced during the infection lasted for a minimum of five months. According to a new study, led by experts from the La Jolla Institute for Immunology in the United States and published in the journal Science, natural immune memory after contracting the disease lasts at least eight months.

The scientists have analysed samples from 188 people who have recovered from covid-19 for antibodies and B and T cells, two parts of the immune system that are responsible, respectively, for helping to produce antibodies and destroying cells infected with the virus. The sample included a wide range of clinical pictures, from asymptomatic to severe cases, but most of the people studied had presented mild symptoms and had not required hospitalisation. The results indicate that in 95% of the patients the levels of the various types of antibodies studied are maintained or, at most, drop slightly after eight months. A similar thing happens with B and T cells.

The authors are characteristically cautious. However, although they state that the specific mechanisms of the immune response that protects against this new coronavirus are not yet sufficiently well understood, they also explain that it is reasonable to think that the antibodies contribute to sterilising immunity, that is, to the fact that the disease does not develop, and that the B and T cells are responsible for reducing the severity of the disease if it does occur. Therefore, they conclude that "long-lasting immunity to re-infection is a possibility for most individuals".