Vaccine industry is being revived

The fact that half of vaccine manufacturers dropped out of the market by the late 1970s exacerbated the problem.

But Greene said major recent advances in vaccine technology had made finds considered unattainable a decade ago look possible.

Improved understanding of immune responses has led to more elusive vaccines, like the ones that have arrived in recent years. Better understanding of the genetic structure of bacteria and viruses, and how to get the body to respond to them more effectively, is fueling the growing optimism for malaria vaccines and other treatments.

In 2004, a small clinical trial of 2,022 children in Mozambique found an experimental vaccine cut the risk of developing severe malaria by 58%.

Separate advances are likely to increase the ability to produce influenza vaccines for routine immunization and, possibly, to protect against a global influenza pandemic.

Traditionally, flu vaccines are grown in millions of fertilized chicken eggs, which can take up to six months. The lengthy process makes it hard for drug makers to keep up with mutating flu strains and limits the amount of vaccine they can produce quickly each flu season.

The egg-based method is problematic for bird flu vaccines because the disease threatens chickens and the egg supply needed to grow the vaccines.

So pharmaceutical companies are developing two methods -- using cell cultures and DNA cloning -- that could speed things up.

Instead of growing the vaccines in eggs, scientists are trying to use cell cultures, which is how vaccines for chicken pox, hepatitis A and polio are made. This summer, the federal government awarded five companies a shared $1 billion to research and implement cell process, which could cut in half the development time for seasonal flu vaccines.

Researchers also are making progress with what are known as DNA vaccines especially for use against the flu. These are made with single genes of a virus, and injected into the skin to produce an immunological response.

Although no DNA vaccine has proved effective yet, scientists say it's a much more direct method for immunizations that holds enormous promise.

daniel.costello@latimes.com

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Immunization boom

Vaccines recently approved or expected soon:

* Pneumococcal disease:

Approved in 2000

* Human papillomavirus:

Approved in 2006

* Rotavirus gastroenteritis,

children:

Approved in 2006

* Shingles, adults:

Approved in 2006

* Herpes simplex:

Expected arrival in 2008

* Rheumatoid arthritis:

Expected arrival in 2012

* Multiple sclerosis

Expected arrival in 2012

Source: Times staff