I’ve been keeping up to date with the latest coronavirus vaccine developments using Derek Lowe’s blog, a resource which I cannot recommend highly enough. A recent post mentioned that vaccines developers are looking out for signs of antibody-dependent enhancement (ADE), which I vaguely remembered from my undergraduate biochemistry days researching an essay on dengue fever. ADE is an interesting immunology phenomenon, and so I thought I’d treat you all to a brief introduction to the issue.