Viral Contaminants found in Infant Vaccines.
This study was passed along by Dr. Mercola and is well worth reading:
by Vincent Racaniello, March 29/2010
Delwart laboratory obtained samples of eight infectious attenuated viral vaccines from the manufacturers: oral poliovirus vaccine (OPV, Bharat Biotech), rubella (Meruvax-II, Merck), measles (Attenuvax, Merck), yellow fever (YF-Vax, Sanofi Pasteur), human herpes 3 (Varivax, Merck), rotavirus (Rotarix, GlaxoSmithKline; and Rotateq, Merck) and multivalent measles-mumps-rubella (MMR-II, Merck). The vaccines were treated with DNAse and RNAse to remove nucleic acids that are not protected by viral capsids. Nucleic acid was then extracted from the vaccine, amplified by polymerase chain reaction, and subjected to DNA sequencing. A total of 501,753 sequence ‘reads’ were done.
The sequence analysis revealed the expected vaccine strains in each preparation, and in three cases, other unexpected viral sequences. The retrovirus avian leukosis virus was found in the measles vaccine, but at a very low level (700 nucleotides from 4 sequence reads). A virus similar to simian retrovirus was identified in Rotateq (276 nucleotides from 1 sequence read). Significant levels of porcine cirovirus 1 were found in Rotarix. The entire viral genome sequence was deduced from 6344 sequence reads, comprising over 40% of the reads done for that vaccine.
The avian leukosis virus sequences found in the measles vaccine are in intact virions, as DNA treatment of the vaccines did not prevent their detection by polymerase chain reaction (PCR). However simian retrovirus DNA was not detected by PCR after DNAse treatment of Rotateq. Therefore the viral DNA detected in Rotateq vaccine most likely originates from host DNA present in the vaccine preparation. The cells used to produce Rotateq are Vero cells – African green monkey kidney cells. A defective form of simian retrovirus DNA, called proviral DNA, is integrated into Vero cell DNA.
How did a porcine virus contaminate Rotarix, which is produced in Vero cells? The answer is not known, but the authors speculate that the culprit might be porcine trypsin, which is used during the propagation of Vero cells. Over 100,000 porcine circovirus 1 DNA molecules were detected in each vaccine dose, fully 10 times higher than the amount of rotavirus present. However, it’s not known if the porcine circovirus present is infectious.