How would Covid-19 vaccine makers adapt to variants? By tweaking their vaccines, a process that should be easier than coming up with the original shots.

Viruses constantly mutate as they spread, and most changes aren’t significant. First-generation Covid-19 vaccines appear to be working against today’s variants, but makers are already taking steps to update their recipes if health authorities decide that’s needed.

Covid-19 vaccines by Pfizer and Moderna are made with new technology that’s easy to update. Updating other Covid-19 vaccines such as AstraZeneca could be more complex.

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