Gene therapies and COVID-19 vaccines: a necessary discussion in relation with viral vector-based approaches.

The COVID-19 pandemic is adding an unanticipated concern for those affected by genetic diseases. Most of the new treatment achievements for these patients are made possible as a result of advances in viral-based products. Among them, adenoviruses (AdV) and especially adeno-associated viruses (AAV) are important players. The concerns and the conversation around this issue have increased as COVID-19 vaccines approach the market. What if the viral vectors become the mainstream strategy for vaccine development? Will the immune response elicited against the vector compromise the efficacy of future gene therapies? Patients with genetic diseases and patient advocacy groups are requesting information to the medical community about the potential impact of these vaccines in future gene therapy treatments, and physicians and scientists are not able to provide satisfactory answer yet. Importantly, the frequency of cross-reactivity among different AAV serotypes can be as high as 50%. This would have potential implications for patients with genetic disorders who could benefit from gene therapies, often coming in the form of AAV-based gene therapies. As in many other aspects, this pandemic is challenging our capacity to coordinate, plan ahead and align different medical objectives. In this case, having such conversation early on might allow us to make the right choices while we are still on time.