Double-Shot Covid Vaccine Tests Raise New Pandemic Challenge

When it comes to protecting the world from the coronavirus, two doses of a vaccine may be better than one. But doubling the number of jabs each person needs could complicate efforts to immunize billions of people.

The latest results from front-runners in the sprint to come up with a vaccine, including the University of Oxford-AstraZeneca Plc partnership and Moderna Inc., highlight that prospect. Both efforts are conducting final-stage testing with two doses.

Producing vaccines and deploying them to the world’s population in the midst of a pandemic would be a massive challenge even if researchers are able to deliver one-dose inoculations. A need for two would make manufacturing and logistics even more complex.

Those challenges would get even tougher if -- as some experts think is possible -- a vaccine’s efficacy wanes over time and repeat doses are needed, potentially every year.

Read more: https://www.bloomberg.com/news/articles/2020-07-20/double-shot-covid-vaccine-tests-raise-new-pandemic-challenge