June 18 (Reuters) - U.S. Health Secretary Robert F.

Kennedy Jr. is considering asking a key government vaccine

advisory panel to examine vaccines that contain aluminum

ingredients, Bloomberg News reported on Wednesday, citing a

source familiar with the matter.

Aluminum-containing adjuvants are ingredients that have been

used in vaccines since the 1930s, according to the U.S. Centers

for Disease Control and Prevention.

An adjuvant, used in some vaccines, helps create a

stronger immune response in people receiving the shot.

Aluminum salts are used in the pneumococcal conjugate

vaccine such as Pfizer's ( PFE ) Prevnar, HPV vaccines such as

Merck's ( MRK ) Gardasil and hepatitis B vaccines.

In all cases, adjuvant-containing vaccines are tested

for safety and effectiveness in clinical trials before they are

licensed for use in the U.S. and once approved, the vaccines are

monitored by the CDC and the FDA, according to the CDC.

The discussions on reviewing such vaccines could evolve,

Bloomberg reported, citing a source who was not authorized to

speak publicly on the deliberations.

Kennedy earlier in June

fired

all 17 members of a CDC panel of vaccine experts, drawing

protest from many vaccine scientists.

The Department of Health and Human Services did not

immediately respond to Reuters' request for comment.