Lakshmi Panagiotakopoulos said she could no longer help vulnerable people after officials removed recommendations to immunize children and pregnant women.

A medical officer at the US Centers for Disease Control and Prevention who was working on the committee that was weighing changes to the agency’s Covid-19 vaccine recommendations resigned on Friday, the same day officials the US Department of Health and Human Services announced they had removed the CDC recommendation for pregnant women and healthy children to get Covid-19 vaccines.

The rewriting of government recommendations will make the effort to get vaccine doses into arms exponentially more difficult, experts say.