 The CDC recommends everyone over the age of six months get a routine annual flu shot every year, unless you have some sort of country indications, such as an allergy to any of the components. They recommend trying to get it by the end of October, but maybe beneficial even December or later. How effective are flu vaccines? It depends on the year, but typically it reduces the risk of getting the flu by about 40 to 50%. So in healthy adults, we can say with moderate certainty, we can decrease the risk of getting it from like 2% each year down to just under 1%. Among older adults, you may get a similar relative risk reduction, but the baseline risk is higher and the consequence is greater, so the absolute benefits are greater too. And kids, flu vaccines really shine a high certainty of evidence of a substantial drop in risk, but even in this kind of best-case scenario with vaccination, there's still a risk. So what else can we do? Each year, Americans experience millions of cases of influenza and hundreds of millions of colds. What about elderberry supplements? In a test tube, elderberry extracts can inhibit pathogens, including the flu virus, and in a petri dish, it can rev up the production of flu-fighting molecules from human immune system cells like tumor necrosis factor, as much as nearly 45-fold, and elderberry juice can help mice fight off the flu bow. What about actual people? The first clinical trial was published back in the 90s. A double-blind, randomized placebo-controlled trial to treat flu-like symptoms and odds for improvement before the fifth day in the treated group were more than 20 times the odds in the control group. Two subsequent double-blind, randomized placebo-controlled trials showed similar accelerated healing in the elderberry groups. This is the study I was excited to see elderberry supplementation for cold symptoms in air travelers, given my 200-city book tour, a randomized double-blind, placebo-controlled clinical trial of 312 economy-class passengers. While taking elderberry didn't seem to prevent people from coming down with cold symptoms, the duration and severity of symptoms in those that did get a cold seem to have been lessened, suffering on average about five days instead of seven. A similar study using the herb Echinacea found a lessening of symptom scores that was of only borderline statistical significance. But if you compile all such studies together, even though most of the individual trials didn't find statistically significant improvements, and put them together, there may be about a 20% decreased cold incidence, though there is a concern about selective reporting and publication bias, meaning a bunch of findings in entire studies seem to be MIA, suggesting maybe negative studies were quietly shelved. So we're really not sure about Echinacea, but all the elderberry studies seem to have positive results, suggesting elderberry supplementation provides an effective treatment option when more serious treatment isn't needed. This conclusion came from some with apparent conflicts of interest, though. In fact, each of the four elderberry studies were funded by the elderberry product companies themselves. Any other berries that might help are randomized, placebo-controlled, interventional study funded predictably by Ocean Spray found that the gamma-delta T cells of those drinking a low-calorie cranberry juice beverage for 10 weeks appeared to be proliferating at nearly five-fold the rate. These immune cells serve as like a first line of defense, though they didn't get fewer colds, but they did seem to suffer less, but not enough to actually prevent days from work or an impairment of their activities. But at least, you know, cranberries have never been reported to cause pancreatitis, some guy taking elderberry extract, not only suffered an attack of acute pancreatitis, a sudden painful inflammation of the pancreas, it went away when he stopped it and then reappeared again years later when he started taking it again, which suggests a cause and a fact. Why take elderberry extracts, though, and you could just eat the elderberries themselves? Well, cooked are fine, but consuming raw elderberries can cause you to puke your guts out. Oh, no, you tell me. I found out the hard way, as I explained in an answer to the question, what was the worst day of my life in my how not to die London Real interview? It turns out elderberry fruit form cyanide, such that eight people had to be medivacked out after someone brought freshly squeezed elderberry juice to a gathering.