Facebook says it is continuing its work to combat vaccine misinformation in the wake of the death of a young child from the flu.

According to NBC News, the four-year-old child died after his mother followed advice given to her from the members of one of Facebooks largest anti-vaccine groups.

The mother was a member of Stop Mandatory Vaccination, one of the largest known health misinformation groups with more than 139,000 members. According to NBC, she asked the group for advice after her child exhibited flu-like symptoms, including a high fever and a seizure. 

None of the recommendations included seeking medical help, and the mother reportedly said she did not pick up a prescription for the anti-viral drug Tamiflu. The child was eventually hospitalized and died. 

According to the Centers for Disease Control and Prevention, there have been more than 19 million cases of the flu reported this season. It has hit children especially hard; the CDC reported 78 child deaths from the flu during the 2019-2020 season. 

In a statement to NBC, Facebook said it is working hard to reduce vaccine misinformation everywhere on the platform, including in private groups. 

But the childs death shows the limits of Facebooks efforts. The company has been reluctant to completely ban anti-vaccine groups on its platform, and instead has implemented policies meant to better promote credible content. 

In March, Facebook announced it was taking steps to limit the circulation of anti-vaccine content on its platform. Under the plan, Facebook will no longer promote anti-vaccine groups and pages in search results, and will not surface them in users’ newsfeeds. 

Facebook-owned Instagram’s search and “explore” features will also no longer promote posts that spread anti-vaccine content.

The company also said it would reject ads promoting false information about vaccines.