J&J pause adds to adenovirus vaccine doubts

The Covid-19 vaccine candidates being developed by Astrazeneca and Johnson & Johnson have a couple of things in common. Both have now been linked with a safety scare, and both use an adenoviral vector.

So far, little is known about the adverse event that caused J&J to pause all of its Covid-19 vaccine trials, including the phase III Ensemble study. But if it turns out to be similar to the neurological issue that caused Astra’s US trial to be put on hold, it would be a big problem for the adenovirus approach.