Can you catch Covid-19 twice?

The hope is that a recovered patient has developed enough Covid-19-specific antibodies to fight off a secondary infection. However, in one study on convalescent patients in China, 30% of those studied had very little or no detectable antibodies in their blood plasma. It would seem that those people were able to neutralise the infection without the need to develop antibodies, either because their innate immune response or the T cells in their adaptive immune response, or a combination of both, were sufficient. Those with the lowest counts of antibodies were most likely to be the youngest patients.BBC