Flu season arrives Down Under

It's flu season! Gotcha. Okay, it's winding down in the Southern Hemisphere and won't get rolling in the northern half of the world for a few more months.

But just because the viruses are mainly Down Under doesn't mean they're not making medical news -- and not necessarily good news.

Development one is data from the World Health Organization that shows about a third of nearly 800 people from South Africa to Chile to Australia tested from April to August were infected with a flu virus strain that's resistant to one of the frontline, anti-flu drugs, oseltamivir, or Tamiflu.

That's about twice the resistance rate detected in the same family of virus from a larger survey done mostly in the Northern Hemisphere between September 2007 and last March.

Tamiflu is one of the drugs people turn to if they realize quickly that they're coming down with the flu. It uses an enzyme that stops the spread of virus from infected to healthy cells. It also is considered one of the stopgap drugs that might be used in the event that a flu pandemic (say from a mutant bird flu strain) should break out.

Now the presumed good news is that the nation's flu experts decided early last spring to order up an entirely new mix of flu strains to be included in the flu shots for the upcoming season.

Last season's vaccine formula turned out to be largely a mismatch for the strain that by January was infecting most people coming down with the flu nationwide.

So the new vaccine mix includes bits of that flavor of virus, A-Brisbane-10-2007, as well as a good match for the strain being found resistant to Tamiflu, A-Brisbane-59-2007, (an H1NI-like strain).

Not only are experts hoping for a better vaccine fit this winter, the vaccine industry and public health agencies across the country are gearing up to deliver a record number of flu shots, starting as early as next month.

With the addition of kids 5 to 18 to the pool of people for whom flu shots are recommended, basically only young babies and healthy adults under 50 who don't work in health care are left out of groups particularly encouraged to get a flu shot this fall.

And flu vaccine manufacturers are well on their way to shipping a record 143 million doses to doctors, pharmacies and clinics, with a goal of having most of the serum in place by the end of October.

Flu is viewed most dangerous for young children and older adults, because their immune systems aren't thought to be as strong as healthy adults in their prime.

But another study involving 32 survivors of the 1918-19 flu pandemic, reported online recently by the journal Nature, found that all still had antibodies that reacted to a 1918 virus protein recovered from the frozen body of a victim buried in Alaskan permafrost.

Researchers were able to recover rare B cells -- immune cells that produce antibodies -- from eight blood samples taken from the survivors - aged 91 to 101, and found they were still ready to defend against a renewed assault from the virus that killed some 50 million people.

They went on to test the antibodies in lab mice infected with the 1918 flu. Those given the highest doses of the antibodies lived, but those given low doses, or none, died.

Scientists involved in the study say it not only demonstrates how long-lived immunity can be, but suggest the antibodies might be reproduced in large quantities to protect people if another virus similar to the 1918 flu breaks out again.

In the meantime, a number of vaccine developers are working with gene-altered bacteria and cold viruses to deliver so-called "universal' flu vaccines that could either block uptake or generate a broad immune response against many flu strains at once.

Ideally, such technology might one day eliminate the dicey choosing of flu strains for the seasonal shots, eliminate the risk of shortages, and offer protection against sudden surges of new and deadly strains of flu.

On the Net: http:www.nature.com

www.cdc.gov/flu/

www.who.int

(Distributed by Scripps Howard News Service, http://www.scrippsnews.com)