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Pfizer and Moderna have both announced promising results in the phase 3 trials of their COVID-19 vaccines. Here’s how they differ.

Storyful

The success of two COVID-19 candidate vaccines marks a turning point in the long history of vaccines and could lead to major advances against a variety of diseases.

Vaccines developed by Pfizer/BioNTech and Moderna are more than 95% effective against COVID-19, trials show. Both depend on a technology never before used in a commercial vaccine that could upend the way future ones are made.

This new messenger RNA technology, as well another method that depends on viruses to deliver vaccines, are transforming the field, said Brendan Wren, a professor of vaccinology at the London School of Hygiene and Tropical Medicine.

“It could be quite a new era for vaccines and vaccinology,” he said. “We seemed to move ahead in this one year 10 years.”

These technologies had