The following information on WI-38 (similar to MRC-5 ~ see below ~) might be useful.
Science, Volume 257, 21 August 1992, page 1027.
Author: Dr Leonard Hayflick.
In his editorial "Fetal tissue research" (26 June p 1741) Daniel I. Koshland, Jr, says that reserarch on the use of fetal tissue "could lead to the development of cell lines or drugs that could be the basis of large-scale therapy." In face, normal human fetal cell strains have been used in precisely this way inthe United States since 1962. Thirty years ago, my colleagues and I reported that a poliomyelitis vaccine produced in such cells was both safe and efficacious. Our human fetal cell strain, WI-38, and similar strains derived from surgical abortions are used in the United States for the production of vaccines against poliomyelitis, rubella, adenoviruses and rabies."
Journal. American Society of Microbiologist, Vol 48, No 3, 1982, pg 122,
About Our members, Leonard Hayflick.
Extract: "He proved experimentally that cultured normal fetal human cells are capable of reproducing only about 50 times, and then they die; cells from older donors age and die sooner. In the course of his studies in 1962, Dr. Hayflick isolated a normal human cells strain (WI-38) which exhibits the Hayflick likit. This strain, which still grows in laboratories throughout the world, can support the growth of most known human viruses...Dr. Hayflicks WI-38 is also the basis for producing superior vaccines now used to inoculate millions of people against polio, measles, German measles, adenoviruses, mumps and rabies."
I have in my hand the Merck Sharp and dohm package insert from an MMR II vaccine given in 1991 (still used today). At the top it says that "live attenuated rubella virus grown in human diploid cell (WI-38) culture, with two reference, 1 and 2.
Ref 1 = Plotkin S.A. et all. "studies of immunisation with living rubells virus: Trials in children with a strain cultured from an aborted fetus. Am J, Dis Children 110: 381 - 389, 1965.
the MMR used today is still cultured from Wi-38, and as far as I know, that is still, as described "from an aborted fetus"
MRC-5 is another "human diploid tissue" which is also from an aborted fetus, and of the vaccines we use, the following also use MRC-5:http://www.medsafe.govt.nz/profs/dat.../havrixinj.htmhttp://www.medsafe.govt.nz/profs/dat...rilirixinj.htm
MMR II continues to use aborted fetal tissue - see bottom under Actionhttp://www.medsafe.govt.nz/profs/dat...m/mmriiinj.htm
Havrix - Hepatitis A is also on MRC-5http://www.medsafe.govt.nz/profs/dat.../havrixinj.htm
Twinrix, a Hepatitis B and A combo is also on MRC-5http://www.medsafe.govt.nz/profs/dat...twinrixinj.htm
Regarding Varivax the following may be of interest:
VARIVAX 1995 data sheet, Merck & Co., Inc. No 7779300:
“…VARIVAX is a preparation of the Oka/Merck strain of live, attenuated varicella virus. The virus was initially obtained from a child with natural varicella, then introduced into human embryonic lung cell cultures adapted to and propagated in embryonic guinea pig cell cultures, and finally propagated in human diploid cell cultures (WI 38). Further passage of the virus for varicella vaccine was performed at Merck Research Laboratories in human diploid cell cultures (MRC-5) that were free of adventitious agents...”
“…Each 0.5 ml dose contains the following: a minimum of 1350 PFU (plaque forming units) of Oka/Merck varicella virus when reconstituted; approximately 25 mg of sucrose; 12.5 mg hydrolysed gelatine; 3.2 mg sodium chloride; 0.5 mg monosodium L-glutamate; 0.45 mg of sodium phosphate dibasic; 0.08 mg of potassium phosphate monobasic; 0.08 mg of potassium chloride; residual components of MRC-5 cells including DNA and protein; and trace quantities of sodium phosphate monobasic; EDTA; neomycin, and fetal bovine serum. The product contains no preservative."
J Pediatrics 1995;127:518-25:
“…The nearly 2 ug of unmodified mammalian DNA in each dose of Varivax exceeds that present in any other approved childhood vaccine”
another extract - they studied the MRC-5 line:“…generally accepted upper limits for chromosomal abnormalities. A clonal 7;12 chromosomal translocation in the MRC-5 cells used to produce some lots of Varivax exceeded these limits for structural abnormalities. To evaluate the theoretical concerns raised by this observation Merck undertook a comprehensive assessment of MRC-5 (aborted foetal) cells to document that they were not tumorigenic. MRC-5 cells from the cell banks used to produce vaccine
(1) did not produce tumours when injected into nude mice
(2) reached senescence normally, and
(3) did not exhibit a malignant phenotype.
Moreover, cells bearing the 7;12 translocation did not proliferate preferentially during the lifetime of the cell line in comparison with MRC-5 cells lacking the translocation. No human disease associated with abnormalities involving a 7;12 translocation has been reported. Outside experts concurred with the FDA’s assessment that the risk of MRC-5 DNA’s inducing a malignant transformation in vaccinees under the condition of vaccination was exceedingly low”
Here is a description of exactly what these cells are:
for those who didn't know how to get around the search on the link provided, here is the description of MRC-5 and the direct link so that you can confirm that MRC-5 is human fetal cells from a 14 week fetus.http://phage.atcc.org/cgi-bin/search...171&text=MRC-5
IRR-MRC-5 [ATCC X-55; ATCC X55; irradiated MRC-5]
Depositors: J.P. Jacobs
Tissue: lung; fibroblast
Comments: These cells are provided to be used as feeder cells to support the growth of other cells.
They have been irradiated and will not replicate.
It is recommended that the feeder cells be plated 24 hours before use.
The cells will begin to deteriorate in 2 to 3 weeks after plating.
Once the feeder cells have attached, the culture medium may be changed to accommodate the cells to be supported.
Age Stage: 14 weeks gestation
That enough for you?