I don't know about the math, but I can understand the factors. You have the primary concerns, which are people who are died, people who are unable to work, people who are unable to have kids. Then you have detrimental effects of drop in births, which is then compounded by the number of people who are unable to have birth.

To throw out some random numbers. 1 million people die directly from covid jabs. 7 million are unable to have birth or take care of themselves. That's probably a decline of 10 million possible babies that would normally have been born.