This is not good news.

How many millions of people got those shots?
So if you got the shots at age 25, you can expect to live another 23 years, and die at age 48?

Wow.
Shockwaves have been sent rippling through the scientific community after a study found that around 30 years have been wiped from the average life expectancy of people who received at least two doses of Covid mRNA "vaccines."
slaynews.com
First,
the journal article referred to by this link is from last year. It's not clear to me why it is treating it as if it's some new article.
Anyway, it claims "The bombshell findings of Prof. Alessandria and his team were published in the renowned Swiss medical journal MDPI." Huh? MDPI is not a medical journal; it's a
publisher of journals. The
journal it's published in is named Microorganisms. Furthermore, MDPI is hardly "renowned", at least not in a positive sense--it's actually been repeatedly criticized for having low quality control when it comes to articles in its journals, so it's "renowned" for having lower quality articles.
So from the get-go we should be a bit cautious trusting the journal article, given MDPI's less than stellar reputation for its journals. But, does even this journal article support the claim? It actually seems like your link plucked one small portion out of context and then wrote up the whole article based on that out-of-context portion. It claims "The alarming study found that the mRNA injections reduce a person’s lifespan by a whopping 37%" and then goes on to claim that this would result in a 30-year reduction in lifetime expectancy. The entire article is based on that assumption of people losing 37% of their lives.
Now, the article is rather technical, so it's hard for me to analyze how accurate or inaccurate some of its claims are. But, again, our purpose here is to determine what the claim actually is. Let's look at the context of that 37% claim.
For those vaccinated with two doses, the loss of life expectancy (RMTL) in 739 days is 1.37 (CI 95 = 1.27–1.48; p < 0.0001) times that of the unvaccinated. This means that the subjects vaccinated with two doses lost 37% of life expectancy compared to the unvaccinated population during the follow-up considered. The difference between the life expectancy (RMST) of the vaccinated and that of the unvaccinated limited to the period considered is −2.71 (CI 95 = −3.40 to −2.01; p < 0.0001) days. However, to have an easily understandable comparison, if we extrapolate this result to the entire life expectancy of the Pescara population, we will obtain a loss of life expectancy difference of about −3.6 months. Obviously, this is an extrapolation made for the sole purpose of giving the reader an idea of the order of magnitude of the RMTL. It may not constitute a realistic prediction, as it would presuppose health conditions to be invariant over time, an assumption that is very difficult to realize.
The first bolded section is where we find the 37%, and the second is when it applies it to someone's full life expectancy. So, when viewed in context, we see that this loss of life expectancy, when applied to the full life of expectancy, says that those vaccinated with two doses will lose, on average... 3.6 months off their life. I don't know how your link misses this, it's
two sentences after the 37% mention. Did they not bother to read their own source? Or did they just stop reading when they saw the "37%" and didn't bother finishing the paragraph? Or are they trying to mislead the reader on purpose for clickbait purposes?
Now, again I lack the knowledge of the subject to try to properly evaluate how accurate the claims of the journal article is. For reasons given before, I'd be on my guard trusting something published by MDPI. But
even if this journal article is absolutely correct about everything, all it's saying is that someone would lose a few months. Your link thoroughly misrepresents what it actually claimed.