Wednesday, October 21, 2009

ASO3 and ASO4 adjuvants--my error

ASO3 is the GlaxoSmithKline adjuvant being used in some swine flu vaccines. It is not being used in the United States. It does contain squalene. It is being used in Canada and Europe. The presence of novel adjuvants in swine flu vaccines has become very controversial in some countries. WHO recommended that countries use the adjuvants to stretch the world supply of swine flu vaccines.


ASO4 (not ASO3) is the GSK adjuvant used in Cervarix and Fendrix (a European Hepatitis B vaccine for patients with renal failure). It contains an aluminum salt and other ingredients. The package insert for Cervarix says it contains aluminum hydroxide, while the Fendrix insert says it contains aluminum phosphate, and refers to the adjuvant as ASO4-C. So it appears the ASO4 adjuvants in the two GSK vaccines are not identical.

Both ASO4 adjuvants contain Monophosphoryl lipid A (aka MPL or MPL-A). MPL has not been included in any previously-licensed vaccines in the US, and is considered a novel adjuvant. MPL is derived from bacterial lipopolysaccharide and is an immunomodulator. When MPL was used in experimental anthrax vaccines, squalene was included in the vaccines. However, neither the Cervarix nor Fendrix package inserts state that these vaccines include squalene. Therefore, my previous posts claiming those vaccines contained squalene are wrong. I will try to clarify the makeup of ASO4, and apologize for this error.

UPDATE: This article, whose authors work for Novartis and have shepherded MF59 along, clarifies the makeup and background of ASO4, ASO1, ASO2 and MF59.


Unknown said...

you aren't alone - I was mixing them up until a week or so ago, myself.
We need to get the patents to see truly what is in them.

They make it purposefully complicated so we are all confused and don't know what is going on

Tween, MPL, Triton, MF59, aso3, aso4 and the beat goes on

Sheri Nakken, RN, MA

Unknown said...

Dr. Nass,
Thank you for your informative weblog.

To your knowledge, has ASO3 been used in any vaccine anywhere for anyone that was not elderly or immune compromised? My research has failed to show anything of the sort. When Novartis refers to the 40,000 who've had MF59 injected into them safely, these are elderly people who took the Fluad vaccine.

In Canada, our entire H1N1 vaccine complement of 50 million doses(short of 1.2M doses for pregnant women) is coming from GSK and contains ASO3. I suspect that as the USA wants more vaccine, it'll start authorizing such adjuvants. Right now, the USA is getting an unadjuvenated vaccine with a decent antigen titer, but it takes longer to create the volume requested because the virus grows so poorly in eggs.

Anonymous said...

ASO4 is in Cervarix. What exactly is the difference between ASO and ASO4. Could it be PZP?