Podcast: Adult Vaccines

We have lots of choices to make about our diet and to that doing the right thing when it comes to treating a chronic disease or fighting a virus or losing weight and suddenly our nutrition choices can seem almost overwhelming. Well, I'm here to help. Welcome to the NutritionFacts podcast. I'm your host Dr. Michael Greger. Today we look at the kinds of shots that protect you as you age and we start with the benefits and side effects of the flu vaccine. Every year influenza typically kills between 4,000 and 20,000 Americans. Though the death toll for the 2017 to 2018 season was estimated at 80,000 making it one of the deadliest in the last half century. Most hospitalizations and 90% of flu-related mortality occurred in those 65 and older and most over the age 75. Mortality rates for the flu at ages 75 and older are 50 times higher than those below age 65. Nevertheless, the CDC recommends everyone over the age of 6 months get a routine annual flu shot every year if for no other reason than to help prevent transmission to the more vulnerable. The cruel irony is that older adults, the ones who need protection the most, acquire less robust protection from flu shots due to waning immunity with age. Depending on the season, vaccination typically 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, even if you get the similar relative risk reduction from 6% down to 2.4% since the risk is higher and the consequences greater, the absolute benefits are greater, too. In the northern hemisphere, the flu season can start as early as September and go as late as March. The problem with getting vaccinated too early in the season is that immunity might wane before the season is over, especially in older adults. So, it might be good to wait until October, but getting it anytime throughout the season is preferable to not getting vaccinated at all. Yes, the influenza can cause Guillain-Barré syndrome, an autoimmune attack on your nerves that can leave you paralyzed for weeks, but so too can getting the flu. There may be one to two additional cases of Guillain-Barré per million vaccinations versus about 17 extra cases per million contacts with the flu virus. So, you're much more likely to be temporarily paralyzed by the flu than the flu shot. But, since it takes vaccinating about 30 older people to prevent one case of the flu, getting vaccinated would still, in expectation, raise your overall Guillain-Barré risk. But, the reason flu shots are recommended is not to lower risk of some obscure autoimmune syndrome, but to reduce the common and potentially devastating impacts of the flu that extend well beyond just the respiratory infection. In the week following a confirmed flu infection, the risk of having a heart attack shoots up sixfold. The inflammation of infection can destabilize atherosclerotic class, constrict arteries, and make the blood more liable to clot. So, might flu vaccination save lives in more ways than one? That's why, indirectly, the flu may kill up to three times more. Those who get their flu shots are indeed less likely to die from cardiovascular disease in a given year, as well as all causes put together. In other words, those who get regular flu shots live, on average longer lives. But who disproportionately gets flu shots? White, married, non-smokers of a higher social class with higher education, higher incomes, and health insurance. You can't tell if it's truly cause and effect until you put it to the test. There have been four randomized controlled trials, flu shots versus placebo shots in those with pre-existing heart disease. And overall, those who got the real shots had a 56% lower chance of dying from cardiovascular disease and a 47% lower chance of dying from all causes put together. So, flu shots really can be an extraordinary life saver. Whether the observational data showing fewer deaths across the board, even among those without pre-existing heart disease, similarly pans out is as of yet unknown. But if you notice for secondary prevention, the randomized controlled trials showed even more protection than the observational studies hinted at. Given the benefits, overcoming vaccine hesitancy should be as simple as correcting misinformation. But sadly, debunking vaccine myths may actually backfire. Busting the myth that inactivated flu shots, the type given to older adults, can give you the flu surprisingly makes people even less likely to get it. Similarly, correcting the falsehood that MMR vaccines cause autism or that pertussis vaccination causes as many side effects as people think, paradoxically makes people less inclined to vaccinate. The researchers conclude, "Correcting vaccine myths may not be an effective approach to promoting vaccination." In the next story, we look at how the new shingles vaccine compares to the previous one. >> [music] >> Adult vaccination can be thought of as a cornerstone of successful aging. But a major issue hampering the uptake of shingles vaccination is the lack of awareness of the disease. Shingles is caused by a reactivation of the chickenpox virus later in life. After your body beats back chickenpox, the virus hides in waiting in your spinal cord waiting for an opportunity to strike back. When it does, the virus can surge forth traveling along the path of a nerve branching off the spinal cord wrapping around one side of the body to the front producing skin blisters along the way in a characteristic belt-like pattern that does not cross the midline in the front. Both shingles and the name of the virus zoster are from the Latin and Greek respectively for belt. The blistering rash can be intensely painful, leave scarring or discoloration behind, but usually disappears in a few weeks on its own. However, approximately 30 to 50% of people suffer postherpetic neuralgia, persistent pain that can last for a year or more that sometimes can be debilitating. Usually it affects nerves around your trunk, but in 10 to 25% of cases it can erupt across your face, which can lead to permanent facial muscle weakness, hearing loss, or blindness. As if that's all not bad enough, having shingles as much as quintuples your odds of having a stroke over the subsequent few weeks, a risk that gradually declines over the following 6 to 12 months. It's surprising more people don't know about it since the lifetime risk of shingles is 30%, meaning nearly one in three will get it sometime in their lives. Young adults only have about a one in a thousand chance of getting it every year, whereas in older adults that climbs to closer to one in a hundred each year. That comes out to a million cases of shingles every year in the United States. Thankfully, there is a shingles vaccine. The first became available in 2006 using a live weakened strain of the virus. The efficacy was only about 50% and couldn't be used in immunocompromised individuals such as those with HIV or on immunosuppressant drugs such as many on chemotherapy. Thankfully, in 2017, a recombinant shingles vaccine was approved with a 90 to 97% efficacy for preventing an outbreak. It requires two separate injections two to six months apart and is expensive, like 280 bucks, but covered by Medicare and most private insurance plans. It also can cause transient systemic symptoms such as muscle aches, fatigue, headaches, or fever and chills serious enough to interfere with several day activities about 10% of the time. But the new vaccine is considered so much more effective that it's recommended for everyone starting at age 50, even if you were previously immunized with the old one. Given that the new vaccine is only about five years old, longer-term safety and efficacy data is still coming in, but >> [music] >> so far, so good. As soon as I turned 50, I lined up for mine. Finally today, the benefits and side effects of the pneumonia [music] vaccine. Vaccines are considered one of the greatest public health achievements of the last century having eradicated smallpox, a scourge that killed hundreds of millions of people and greatly reducing other major diseases such as measles and polio. To this day, vaccines are estimated to save millions of lives a year. More than 90% of US children get common childhood vaccinations such as polio or their measles, mumps, and rubella shot, but most adults fail to get their full complement of recommended adult vaccinations. Assuming you got all your childhood vaccinations and aside from any emergent pandemic needs, the CDC recommends all healthy adults get annual flu shots, tetanus boosters every 10 years, though the World Health Organization doesn't think this is necessary, shingles vaccination at age 50, and pneumonia vaccine at age 65. Certain groups need others, such as a hepatitis B series for healthcare workers or men who have sex with men. Ask your medical professional for a personalized schedule. How safe are vaccines? In a systematic review and meta-analysis, the RAND Corporation screened more than 50,000 citations and concluded that routine vaccinations can be considered safe with only rare serious adverse effects, such as severe allergic reactions in 1 to 10 in a million, and transient autoimmune syndromes, Guillain-Barré and immune thrombocytopenic purpura in 1 to 3 in a million, and 10 to 30 in a million for flu shots and MMR vaccines, respectively. Of course, any adverse effect should be weighed against any protective effects that vaccines may provide. In my last video, I talked about the effectiveness of flu vaccines. What about pneumonia vaccines? "Pneumonia may well be called the friend of the aged," wrote the father of modern medicine, Sir William Osler, over 100 years ago in 1898. "Taken off by it in an acute, short, not often painful illness, the old man escapes those cold gradations of decay so distressing to himself and to his friends." The thought was that pneumonia mercifully killed those who would soon die anyway from potentially more protracted painful illness. But these days, healthy older adults hospitalized for pneumonia are not significantly more likely to die in the subsequent 2 years than younger adults in the same situation. Because of comorbidities at At ages, though, pneumonia is the fourth leading cause of death in the world and the ninth leading cause in the United States. The most common cause of community-acquired pneumonia, as opposed to hospital-acquired, is a bacteria known as pneumococcus or streptococcus pneumoniae. In addition to pneumonia, pneumococcus can cause inner ear infection, sinusitis, or pinkeye. It gets serious when it starts to invade the bloodstream, which can result in meningitis, infection of the brain, endocarditis, infection of the heart valves, or sepsis, a life-threatening organ dysfunction caused by blood poisoning. Thankfully, we have vaccines against pneumococcus. The first was developed over a century ago, but they fell out of favor after penicillin was discovered, thinking antibiotics would eliminate the threat. Unfortunately, these days up to 40% of these kinds of streptococcal infections are resistant to at least one antibiotic, and despite our miracle drugs, mortality rates of invasive pneumococcus in the elderly remain around 15 to 30%. However, randomized controlled trials have found that pneumococcus vaccines reduce the risk of those 65 and older getting pneumococcal pneumonia by 64% and even more importantly, your risk of invasive pneumococcal disease by 73%. Like the flu vaccine, population studies have found that pneumonia vaccines can reduce the risk of both heart attacks and the overall risk of dying, but unlike flu vaccines, there aren't randomized controlled [music] trials to confirm these bonus benefits. Visit nutritionfacts.org/audio to see all the podcast episodes with descriptions that include links [music] to their associated videos, sources cited, and other details are available on each video's page. Information about my books, How Not to Die, How Not to Diet, and How Not [music] to Age is all at nutritionfacts.org/books, [music] including some of the newer titles including lowering LDL cholesterol naturally with food. All proceeds from all book sales that I get go to charity. And I've got a new book in the publication pipeline, How Not to Hurt. It's going to be available in December 15th of this year, 2026. [music] And don't forget to sign up for our free newsletter nutritionfacts.org/subscribe [music] to stay updated on the latest bite-size videos and articles. [music] Nutritionfacts.org is a science-based nonprofit and everything on the website is free. There are no ads, no corporate [music] sponsorship, no kickbacks, strictly non-commercial, not selling anything. Just put it up as a public service, as a labor of love, as a tribute to my grandmother whose own life was saved with >> [music] >> evidence-based nutrition. Thanks for listening.