My patient caught Covid-19 twice. So long to herd immunity hopes.

[Chemisse]

32. This is not totally surprising considering recent studies about antibodies.

Here is one article about a study from last month:

You May Have Antibodies After Coronavirus Infection. But Not for Long.

https://www.nytimes.com/2020/06/18/health/coronavirus-antibodies.html article, which refers to this study: https://www.nature.com/articles/s41591-020-0965-6

Antibodies — protective proteins made in response to an infection — may last only two to three months, especially in people who never showed symptoms while they were infected.

The conclusion does not necessarily mean that these people can be infected a second time, several experts cautioned. Even low levels of powerful neutralizing antibodies may still be protective, as are the immune system’s T cells and B cells. But the results offer a strong note of caution against the idea of “immunity certificates” for people who have recovered from the illness, the authors suggested.

Antibodies to other coronaviruses, including those that cause SARS and MERS, are thought to last about a year. Scientists had hoped that antibodies to the new virus might last at least as long.

“These reports highlight the need to develop strong vaccines, because immunity that develops naturally during infection is suboptimal and short-lived in most people.”