65-аас дээш насны хүмүүст өндөр тунт вакцин хийлгэсэн бүлгийн Альцгеймерийн эрсдэл стандарт тунтай бүлгээс бага байжээ.
Техасын Их Сургуулийн Хьюстон дахь Эрүүл мэндийн шинжлэх ухааны төвийн судлаачид 65 ба түүнээс дээш насны 165,000 орчим хүний эрүүл мэндийн мэдээлэлд дүн шинжилгээ хийжээ. Өндөр тунт томуугийн вакцин хийлгэсэн хүмүүсийн Альцгеймерийн өвчнөөр өвчлөх эрсдэл дараагийн хоёр жилд стандарт тун хийлгэсэн хүмүүсийнхээс 22 хүртэл хувиар бага байв. Өндөр тунт вакциныг жил дараалан хийлгэсэн хүмүүсийн хувьд энэ хамаарал арай удаан үргэлжилсэн бөгөөд эмэгтэйчүүдэд эрэгтэйчүүдээс илүү хүчтэй ажиглагджээ.
2022 онд нийтэлсэн өмнөх судалгаанд 65-аас дээш насны АНУ-ын 1.9 сая орчим хүний мэдээллийг шинжлэхэд томуугийн ямар ч тунгийн вакцин хийлгэсэн хүмүүсийн Альцгеймерийн эрсдэл вакцин хийлгээгүй хүмүүсийнхээс ойролцоогоор 40 хувиар бага байсан. UTHealth Houston-ийн мэдээлснээр, өмнөх үр дүнг шинэ судалгаатай хамтатган авч үзэхэд өндөр тунт вакцин хийлгэсэн хүмүүсийн эрсдэл бараг 55 хувиар бага байжээ. АНУ-ын Өвчний хяналт, урьдчилан сэргийлэх төв 2022 оны байдлаар 65-аас дээш насныханд стандарт вакцинаас томуугийн эсрэгтөрөгч дөрөв дахин их агуулсан өндөр тунт вакцин хийхийг зөвлөж байв.
Судалгааны дүн Neurology сэтгүүлд нийтлэгдсэн ч шалтгаан-үр дагаврыг нотлохгүй. Судалгаанд оролцоогүй тархвар судлаач Эрин Абнер өндөр тунт вакцин хийлгэсэн хүмүүс стандарт тун хийлгэсэн хүмүүсээс өөр, эсвэл эрүүл мэндийн хувьд илүү байж болох тул ажиглагдсан хамаарал санамсаргүй байж болзошгүйг анхааруулжээ. Түүнчлэн судалгааны хугацаа Альцгеймерийн өвчний явцтай харьцуулахад богино байв.
Судлаачид вакцин хийлгэхээс өмнөх хоёр жилд томуугийн ямар ч тунгийн вакцин хийлгэсэн хүмүүсийг шинжилгээнээс хасахад Альцгеймерийн эрсдэлтэй холбоотой хамаарал үндсэндээ арилжээ. Өвчин шинж тэмдэггүйгээр олон жил үргэлжилж болдог тул вакцин хийлгэх үед зарим оролцогчид өвчний суурь явцтай байсан байж болох бөгөөд вакцин өвчнөөс сэргийлэхээс илүү шинж тэмдэг илрэхийг хойшлуулсан байх боломжийг судлаачид дурдсан байна. Вакцин хийлгэснээс хойш нэг сарын дотор Альцгеймерийн онош авсан хүмүүсийг хасахад хамгаалах хамаарал найман сарын дараагаас статистикийн ач холбогдолтой болж, нийт оролцогчдын дунд хоёр орчим жилийн дараа статистикийн ач холбогдолгүй болжээ.
Дэлгэрэнгүйг эх сурвалжаас харах
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Vaccination is emerging as one of the most promising ways to protect yourself against future cognitive decline.
Inoculations for shingles, the respiratory syncytial virus (RSV), pneumococcal disease, tetanus, and diphtheria have all been tied to a reduced risk of dementia.
The annual flu vaccine is also part of the mix.
But a new study suggests that a stronger dose could be even better for dementia risk, compared to a standard flu shot.
When researchers at the University of Texas Health Science Center at Houston analyzed the health data of nearly 165,000 adults aged 65 and older, they found that those who received a high-dose influenza vaccine had up to a 22 percent lower risk of developing Alzheimer’s disease over the following two years than those given a standard-dose shot.
Combined with earlier findings for people with no flu vaccination, that’s nearly a 55 percent lower risk of developing Alzheimer’s disease, according to UTHealth Houston.
If a participant received repeated annual high-dose flu vaccines during that time period, rather than standard-dose ones, their lower risk of Alzheimer’s lasted slightly longer.
An even stronger association was observed among women compared to men.
The findings, published in Neurology, suggest that protection from viruses may also protect future brain health.
The research cannot prove cause and effect, and it comes with some limitations, namely the short time span compared to Alzheimer’s progression.
But it is the first study to investigate whether high-dose flu vaccination is associated with a lower Alzheimer’s risk than standard-dose vaccination.
If you’ve never heard of a high-dose flu vaccine, you aren’t alone.
One of the study’s authors hadn’t either.
In 2022, a data analysis by some of the same researchers found that among nearly 1.9 million US adults aged 65 and older, getting any dose of a flu vaccine was linked to a roughly 40 percent reduction in Alzheimer’s risk compared with no flu vaccine.
“The public health department had seen our vaccine research and asked if I could come down to talk to them about it,” explains neurologist and senior author Paul Schulz from UTHealth Houston.
“We went through the findings, and they asked if there was a difference with different dosages; I was confused.
“I was stunned that, as a physician, I didn’t know a higher dose was offered.”
As of 2022, the US Centers for Disease Control and Prevention (CDC) recommends that people over the age of 65 receive a high-dose influenza vaccine, with four times as much influenza antigen as a standard shot.
This vaccine is designed to trigger a stronger immune response in patients, which can be helpful for older people whose immune systems may be slowing down or weakening.
But while many physicians are aware that annual flu vaccines are recommended, especially for older people, there may be a lack of knowledge surrounding the available dosages.
Erin Abner, an epidemiologist who was not involved in the study, told Neurology Today that these findings support current vaccine recommendations for older folk.
But she cautions that this doesn’t prove causation.
The results could still be a “spurious association,” Abner explained, “due to people who can and do get the high-dose vaccine being somehow different or healthier than people who get the standard-dose vaccine.”
In further analyses, Schulz and colleagues found that if they removed all participants who had received a flu vaccine, of whatever dosage, in the two years before their study vaccination, the association with Alzheimer’s largely disappeared.
Because dementia can take decades to become symptomatic, people diagnosed with Alzheimer’s in this recent study likely had the underlying disease already when they received their flu vaccine.
This raises the possibility that the vaccines may be delaying the onset of dementia symptoms, perhaps by reducing inflammation, rather than preventing the underlying disease itself.
When the researchers removed all participants who received an Alzheimer’s diagnosis within a month after the flu vaccine, they found that the protective association did not become statistically significant until eight months after vaccination.
What’s also interesting is that for all participants considered, the association between Alzheimer’s risk and the high-dose flu vaccine petered out after about two years.
After that, it was no longer statistically significant.
This is one of the challenges of studying whether vaccines lead to dementia protection.
It’s a silent disease that can sneak up on us for decades before its symptoms show.
How does an annual vaccine fit into that picture?
Scientists are on the case.
The research has been published in Neurology.
This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
