They have “lost” antibodies. Which is normal. Those types of cells don’t last long. B & T cells on the other hand last a very long time. In the case of MERs, a

They have “lost” antibodies. Which is normal. Those types of cells don’t last long. B & T cells on the other hand last a very long time. In the case of MERs, a coronavirus from the same family, immunity is still present for more than a decade.