In 1985 my mother was exposed to German Measles due to a failure in herd immunity. Herd immunity is created when the "herd" is vaccinated to the point where the disease, infection, or bacteria has nowhere to go, and no hosts to hide in.
This is a lie and those who "edit" these media outlets have a responsibility to correct it before publication.
Herd immunity does not prevent individual infections. To do so you'd need 100% effective coverage and you never obtain that. Among other things there are people who do not get vaccinated; some for personal reasons, some for medical reasons. To obtain 100% coverage you'd have to force all of those people to be vaccinated including those who were at serious risk of being killed by the vaccine itself, such as those who have severely-compromised immune systems, and even doing that would not achieve it, since immunity failure even if you do take a given vaccine does happen.
Herd immunity is the goal of reducing the transmission rate of a given infection to below 1.0. That is, for a given person who is already infected for the disease to spread it must infect at least one more person. If it does, it spreads exponentially. If it does not, that particular group of infections eventually dies out. If an particular infection has a transmission of 0.9 then if there are 100 infected people in a population they infect 90, who infect 81 and so on -- until it reaches zero.
HERD IMMUNITY DOES NOT PREVENT TRANSMISSION. THAT IS A COMMON AND DAMNABLE LIE AND ANYONE WHO SPEAKS THAT LIE DESERVES TO BURN IN HELL. IT'S DAMNABLE BECAUSE THOSE WHO ARE VACCINATED BUT FAIL THE IMMUNITY BUILD, WHICH TYPICALLY CANNOT BE DETECTED UNTIL EXPOSED (AT WHICH POINT IT'S TOO LATE, AS WAS THE CASE WITH THIS WOMAN'S MOTHER) OR WHO CANNOT TAKE THE VACCINE FOR MEDICAL REASONS ARE LED TO BELIEVE THEY ARE SAFE WHEN THEY ARE NOT.
My mother remembers getting a rash all over her body on Valentine's Day and being sick for a week. She didn't know what it was. She didn't know she needed her MMR vaccine booster, as they weren't standard at the time (as they are now). The other thing that she didn't know? She was pregnant at the time. With me.
As a result, I was born with Congenital Rubella Syndrome. I had cataracts in both eyes, a heart defect and hearing loss, plus a handful of other weird symptoms that I would find out later are classically CRS related but didn't seem so at the time.
Reality is that if you either (1) can't take the vaccine or (2) have immunity failure and did take the vaccine if exposed you will still likely contract the disease. Herd immunity just decreases the number of additional people who, when exposed, will contract it to less than 1.0 for each person who becomes sick.
There are other ways to obtain herd immunity than vaccination. For example if you can detect exposure before contagion occurs in a given person you can isolate them until the disease has run its course and produced natural immunity, which is superior to vaccination in that it has much closer to 100% odds of producing lifetime immunity in a given person. (Of course this assumes you survive the disease itself!) If you are successful in quarantining people in this fashion you also produce herd immunity and you do so without vaccines. The problem is that it requires a level of medical surveillance that is completely impractical to obtain for highly-contagious diseases such as measles, which have natural transmissions efficiencies in non-immune populations that boggle the mind.
The cruel hoax run by places like CNN and other media and medical outlets, and which has a political bent to it, is that due to the lack of 100% coverage from vaccines -- a level of coverage that is scientifically impossible to obtain -- with or without vaccination you must still make a maximum effort to prevent disease carriers from entering the population in order to avoid those without immunity from becoming severely ill.
That means you must police those who enter your nation and that means that unregulated entry of any sort is a severe threat to public health and must be prohibited.
In short unregulated entry -- illegal immigration -- kills people.
Of course that is contrary to the "narrative" that walls are immoral and that people like the "Dreamers" are "just looking for a better life."
Uh, no. Every person who comes into this nation through other than a regulated, screened point of entry is a potential disease carrier and some percentage of them are carrying active infections.
We regulate the transport of agricultural goods and demand inspection at points of entry to attempt preventing this risk among livestock and plant species. One of the primary purposes of limiting crossing into the United States (or any other nation) at controlled points staffed by persons who can inspect those who enter is to apply said controls to humans and the infectious diseases they may carry with them.
Such surveillance is never perfect and never can be but intentionally aiding and abetting the destruction of said surveillance by advocating for or permitting in any form illegal immigration that by its nature evades such surveillance is not only insane it's a criminal act of intentionally exposing people to infectious diseases -- and must be stopped.