Editor,

The following is in response to the Feb. 20 letter to the editor by Ed. A. Drum.

Mr. Drum made unsubstantiated claims about how the MMR vaccines are developed.

Here is the pertinent language from the FDA website of the package insert included with each vial of Merck’s vaccine:

“M-M-R II is a sterile lyophilized preparation of (1) ATTENUVAX (Measles Virus Vaccine Live), a more attenuated line of measles virus, derived from Enders’ attenuated Edmonston strain and propagated in chick embryo cell culture; (2) MUMPSVAX (Mumps Virus Vaccine Live), the Jeryl Lynn™ (B level) strain of mumps virus propagated in chick embryo cell culture; and (3) MERUVAX II (Rubella Virus Vaccine Live), the Wistar RA 27/3 strain of live attenuated rubella virus propagated in WI-38 human diploid lung fibroblasts.{1,2}

“The growth medium for measles and mumps is Medium 199, a buffered salt solution containing vitamins and amino acids and supplemented with fetal bovine serum, containing SPGA: sucrose, phosphate, glutamate, and recombinant human albumin, as stabilizer and neomycin.

“The growth medium for rubella is Minimum Essential Medium (MEM) [a buffered salt solution containing vitamins and amino acids and supplemented with fetal bovine serum] containing recombinant human albumin and neomycin. Sorbitol and hydrolyzed gelatin stabilizer are added to the individual virus harvests.”

www.fda.gov/downloads/BiologicsBloodVaccines/UCM123789.pdf

I have included the link so anyone can check for him or herself.

Marcia Nelson

Oak Harbor