As the days shorten and the weather cools, the flu season approaches. Medical experts, locally and nationally, strongly advise people to get their flu shots.

The flu season typically doesn’t get underway in earnest until November, but the vaccine needs two or three weeks to generate its full immune effect.

Although it’s too early to predict how dangerous this year’s flu season will be, experts point out that the influenza experience in the southern hemisphere often anticipates what will happen in the northern hemisphere.

One who makes that point is Dr. Randy Bergen, a pediatric infectious disease specialist with Kaiser Permanente’s Diablo region, which includes Pleasanton and Dublin.

Bergen leads Kaiser’s anti-flu efforts in Northern California. He noted in an email that “Australia just weathered one of its worst flu seasons on record, which can mean a severe flu season is on its way to the U.S.”

Writing last weekend in the New York Times, physician Donald McNeil noted a grim bit of recent history: Two years ago, the harsh 2017-2018 flu season “Down Under” preceded one of the worst U.S. flu seasons in decades. Some 79,000 Americans died of flu and its complications.

That’s about how many Americans die in two years of car crashes.

Community protection through vaccinations and good hygiene can mean the difference between a mild flu season and a harsh one with high levels of absenteeism, hospitalization and deaths.

Young Children and the elderly

Protection against the flu is important for everyone, but especially for very young children, the elderly, and those suffering already from other serious illness, notes Dr. Jake Scott, an infectious disease specialist with Stanford Health Care-ValleyCare in Pleasanton.

The U.S. Centers for Disease Control estimated that 80 percent of the 180 children known to have died of influenza during 2017-18 had failed to get their flu shots.

Two studies presented last week at a medical conference in Washington, D.C., gave more detail on the protective effects of flu shots in people of varying ages.

One study, carried out at seven pediatric medical centers, found that vaccinated children were 46 percent less likely to be hospitalized than unvaccinated children.

That study looked at the records of 3,441 children hospitalized from the flu during the 2016-17 and 2017-18 flu seasons.

The other, larger study, of more than 43,000 adults, found that those vaccinated against a common flu type, H1N1, were significantly less likely to have to be admitted to intensive care.

For those 65 and older, the reduction was by 28 percent, while for those 18 to 64, the reduction was by 19 percent.

For the 18- to 64-year-olds, those vaccinated were 17 percent less likely to get pneumonia and 36 percent less likely to die.

Statistics like these buttress the views of people like Kaiser’s Bergen and Stanford-ValleyCare’s Scott, who treat influenza patients on a daily basis during the flu season.

Grudging Respect

Scott has developed a grudging respect for influenza for both personal and professional reasons. He has young children, one of whom was too young last year (under six months) to be vaccinated.

“The flu can be very serious, especially in a young kid,” he said.

“Last year I saw a fatal case of influenza related to complications. As a parent, too, (flu shots are) increasingly important in terms of public health benefits.”

People who get vaccinated protect not only themselves, he said. They also protect those around them including people who are not immunized.

In addition to the very young, these may be adults with certain medical conditions and compromised immune systems, who can’t safely be vaccinated.

Such people are highly vulnerable because flu victims can become contagious before they know they are sick, Kaiser’s Bergen says.

Even if they would be willing to stay home, they may not know they should, so they circulate and endanger others.

Most years, only about half the population gets vaccinated. That fraction should be a lot closer to 100 percent, Bergen believes.

“Even the young and healthy need a flu vaccine every year,” he said.

“It is possible to catch the flu and not show symptoms for two days. During that time, you can pass the flu on to others.

“It’s important to get vaccinated early because it can take about two weeks to build immunity… Last year was the longest flu season in decades, with 36,400 to 61,200 flu-related deaths, according to the Centers for Disease Control.”

Death Among the Elderly

During the exceptionally harsh 2017-8 flu season, more than 12,000 Americans aged 65 and older died of the flu, according to AARP, which pays close attention to issues involving the elderly.

Whether this year’s season is equally severe or turns out to be milder, the elderly generally are more frail, less able to stand up to the medical stresses that a serious infection brings.

Scott has pointed out that fallout from the inflammatory storm caused by the flu can lead to increased risk for stroke and heart attack.”

Surveys show that the elderly are more likely to get flu shots than other demographic groups, but they also have less responsive immune systems.

This observation motivated the development of a high dose vaccine with four times more antigen than standard vaccines. (Antigens are the part of the vaccine that triggers the immune response.)

The high dose vaccine protects against three virus strains rather than the four of the standard vaccines. Scott recommended the high dose for seniors, if available.

If it is not – supplies sometimes run out – get the standard vaccination, he and others say.

No one claims that getting a flu shot means you can’t possibly get the flu. Flu viruses are too diverse and too changeable for 100 percent protection. Vaccination does improve the odds, however, and it eases the symptoms of those who do get sick.

In short, partial protection is better than none.

In the meantime, follow simple but effective procedures for reducing exposures to viruses. They include frequent hand washing, the use of alcohol gel, and keeping hands away from face and eyes.

If you do get sick, stay home. Don’t spread your illness to others.