You have made an implication, without basis, that the immunization policies in the US are "unconditionally pro", or at least that the people here are "unconditionally pro."
This is not the case. Read any of the CDC, NIH, or WHO history of vaccinations and you'll see the reasons for the decisions. You'll see the numbers of how much it costs to vaccinate, how much it costs to treat, the likelihood of disease, the likelihood of death, and the effect of side-effects. You'll see research to reduce those side-effects, like improved treatment methods for those with egg allergies.
You'll see treatment policies change over time. The polio vaccine in the US use to be the more effective Sabin vaccine, which used attenuated vaccine strains that occasionally mutated to a more virulent form that gave 144 known cases of vaccine-associated paralytic polio (VAPP) between 1980 and 1999.
Since polio doesn't exist in the US, we switched to the deactivated form in 2000. This isn't as effective, which is why there's now one more shot in the vaccination series, but the old treatment, if continued, would have been deadlier.
There has always been a policy to allow people to opt out of vaccines, usually for religious reasons. (The last outbreak in the US was among Amish groups. The virus came from the Netherlands.) A reason why is because there will always be resistance to any mandate, and vaccines don't require 100% coverage to be effective in a population. It's better to let a few not be vaccinated than to use the indiscriminate and blunt threat of government intervention against them.
This means the CDC and others have to be very cautions and sensitive. For example, even though there's no evidence that mercury preservatives in vaccines cause side effects, you'll see that the vaccines were reformulated to remove thimerosal. The general policy is to minimize objections to the process, and not to force people to comply.
This is absolutely not an "unconditionally pro" policy, so you are downvoted because you're speaking out of ignorance and a blithe appeal, as jlgreco rightly points out, to an argument to moderation.