Advisers from the Centers for Disease Control and Prevention in the United States voted for a recommendation that people with impaired immune systems should be vaccinated with a third dose of Covid.

Eleven members of the CDC Immunization practice Advisory Committee voted on Friday to support a third dose of the vaccine for people with impaired immune systems. This proposal is subject to final approval by Rochelle Walensky, director of the Centers for Disease Control and Prevention.

The US Food and Drug Administration expanded its emergency use authorization for Moderna Inc and Pfizer Inc-BioNTech vaccines late Thursday to allow enhanced injections. Patients with organ transplants and similar impaired immune systems will be eligible for booster injections.

FDA's decision was supported by the results of a study published Wednesday in the New England Journal of Medicine. The study showed that the third dose of Moderna Inc vaccine significantly increased the Covid antibody level of 55% of organ transplant patients. The study found that only 18% of people in the control group who received the placebo produced the required antibody levels.