Pharmaceutical giant Pfizer shared promising results Thursday regarding its COVID-19 booster dose for children aged 5 to 11.

The company said that an additional shot of its mRNA vaccine increased antibodies against Omicron by 36 times for the age group, based on data it conducted from a subset of its a 140-person study. The children participating in the study had no indication of a prior COVID-19 infection, and no safety issues were observed.

Pfizer's booster vaccine for the age group is 10 micrograms, just like previous doses. For comparison, adults receive 30 micrograms.

This findings come as the Food and Drug Administration's lead on vaccine safety, Dr. Peter Marks, said that if additional COVID shots are to be made available this fall, a decision regarding future doses needs to be made in June. Other vaccine manufacturers, such as Moderna, are currently working to create variant-specific doses.

"Many variants are coming, and Omicron was the first one that was able to evade, in a skillful way, the immune protection that we're giving," Pfizer CEO Albert Bourla told CBS last month.

The World Health Organization has urged nations worldwide to ensure 70% of their populations have received their COVID-19 vaccines halfway through the year. According to the U.N. health agency, however, 75 nations have vaccination rates under 40%.

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