About the retroviruses in the MMR...I've found day one of the meeting:
http://www.fda.gov/cber/minutes/0907evolv.txt
(starting on page 47...FDA link, no copyright)
(The speaker is said on page 26 to be Dr. Elwyn Griffiths from the World Health Organization)
So the WHO was worried about what???
What was the WHO's primary concern, and why?
http://www.fda.gov/cber/minutes/0907evolv.txt
(starting on page 47...FDA link, no copyright)
(The speaker is said on page 26 to be Dr. Elwyn Griffiths from the World Health Organization)
Quote:
| Now we mustn't think, of course, that we know everything at this stage. I mentioned that we have had enormous progress in the last 30 years or so. We must be prepared for surprises. Two recent events I think have raised awareness of the challenge there is in dealing with viral contamination of cell lines and vaccines which are used in their preparations and the consequences. One was the detection of very low 48 levels of reverse transcriptase in chicken cell- derived vaccines using this newly developed assay -- we call it PERT assay. This is from -- like measles vaccine is an example and mumps is another example. All the vaccines produced in eggs will contain very, very low levels of RTAs. And this, of course, when it first was discovered raised a lot of alarm bells. People were thinking, yes, there must be retroviruses in here and so on. And this really led to quite a lot of activity trying to show where this activity was coming from. Is it real retrovirus or what do we have there? What is the problem? Or do we just have some non-specific activity which really looks like reverse transcriptase? And much work -- and WHO was very much interested in this, of course, because if national control authorities of one country ban a vaccine because it is considered to be potentially unsafe, this has ripples throughout the whole of the vaccine community. I mean, what is not safe for one set of kids in one country must be unsafe for other kids of course. So there was a lot of work to try and make sure that this activity -- where did it come from and so on. And manufacturers and the national control authorities were very active here. It has now been 49 shown to be particle associated, but extensive studies have shown no transmission or productive infection, and that of course is good news. But as we will hear later on in the meeting, what about the potential for interaction between these particles and some of the viral vaccines -- the actual virus which is used for producing the vaccine during growth. We need to be sure -- I am thinking of pseudotypes and so on here. This is an issue which we need to address in this meeting. |
What was the WHO's primary concern, and why?
