Although flu season is still at least a month way - not that anything having to do with influenza is entirely predictable - the season for flu shots has already begun.

This year's flue vaccine contains protection against the so-called Russian, Texas and B-Hong Kong influenzas, all of which were around last year and all of which are expected to make repeat appearances this flue season.

Of the three, Russian flu is the strain the experts are betting on as the most prevalent, as it appeared at the end of last winter and therefore is likely to be the dominant strain this year.

The panel of experts convened last winter by Health, Education and Welfare Secretary Joseph Califano in the face of the Russian flu scare has recommended that only those persons in so-called high risk categories be immunized this year.

Anyone with a serious chronic condition, such as heart or lung disease, kidney disease or diabetes, is considered high risk, as is anyone 65 or older.

However, says Dr. David Brandling-Bennett, of the federal Center of Disease Control, in Atlanta, "the advisory committee on immunization practices does not recommend the vaccine for people not in the high-risk groups. It's a double negative. We don't advise them to get the vaccine but we don't advise them not to."

Unlike 1976, when the federal government launched a highly controversial nationwide immunization campaign to prevent an epidemic of socalled swine flu - a threat that never materialized - th experts have not recommended a nationwide campaign against the Russian flu.

Rather, they have opted for a return to our standard national practice of making vaccine available for those in the high-risk categories and others who are particularly eager for protection against influenza.

The decision to have a flue shot or not to have a shot basically comes down to taking a health gamble.

On one hand, through the swine flu experience we learned that about one person in 100,000 who is immunized against influenza will develop Guillan-Barre syndrome, a generally self-limiting form of parlysis that usually goes away within a matter of weeks. About one in every 1 million to 2 million people who do develop Guillan-Barre will die from it.

On the other hand, some schools in this country experienced an infection rate as high as 80 percent when the Russian flu struck last winter.

And while influenza is generally a benign disease in an otherwise healthy individual, it makes one feel miserable and causes countless days lost from school and work.

So does one risk the infintestimal chance of paralysis or death - one estimate is that you have the same chance of being struck dead by Guillan-Barre you do of being struck by lightning - and avoid the flu, or do you avoid Guillan-Barre and risk the flu?

One factor in making such a decision is age. If a person is over 25, the odds are that he or she has been exposed to flu similar to the Russian variety some time, therefore has some natural immunity against it.

On the other hand, those under 25 who did not have the Russian flu last season probably have no natural immunity.

What it all comes down to, then, is choosing between the two risks and then talking to one's physician, to see which risk they feel is the most sensible.