The protein syncytin, which is essential for formation of the placenta, originally came to the genome of our ancestors, and those of other mammals, via a retrovirus infection. Placental structures have also developed in non-mammalian vertebrates. The Mabuya lizard (pictured: image credit), which emerged 25 million years ago, has a ...

The TWiVerinos discuss restriction of dengue virus vaccine by Sanofi, and data which suggest that Dengvaxia causes enhanced disease in previously uninfected recipients. <span data-mce-type="bookmark" class="mce_SELRES_start"></span>&lt;span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"&gt;&lt;/span&gt;&amp;lt;span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"&amp;gt;&amp;lt;/span&amp;gt;&amp;amp;lt;span data-mce-type="bookmark" style="display: inline-block; width: ...

A dengue virus vaccine was recently developed not only to prevent first infections, but to avoid severe disease that may occur upon second and third infections. This consequence, called antibody dependent enhancement (ADE), now appears to be caused by the vaccine itself. Primary dengue virus infection may lead to a ...

The TWiV ninjas reveal that bacteriophage particles rapidly move across monolayers of eukaryotic cells from different tissues. <span data-mce-type="bookmark" class="mce_SELRES_start"></span>&lt;span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"&gt;&lt;/span&gt;&amp;lt;span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"&amp;gt;&amp;lt;/span&amp;gt; Click arrow to play Download TWiV 470 (71 MB .mp3, 117  min) ...

The influenza virus vaccine is frequently updated to ensure that it protects against infection with circulating virus strains. In some years the vaccine matches the circulating strains, but in others, there is a mismatch. The result is that the vaccine is less effective at protecting from infection. During the 2014-15 ...