O.K. lets take a 'short' airline trip.
Imagine we visit a 'witch doctor' living in a village which observes ancient traditions but is located near to modern culture so some modern influences and technology are present. The witch doctor 'milks' some sores on a sick cow. Then proceeds to sacrifice a baby. The baby's flesh is mixed with the cow pus. Then the witch doctor visits a cousin living in the city who works at a mortuary. Some containers of embalming fluid are borrowed and mixed into the rotting mix. As beer is magic, a couple aluminum cans are added to the mixture.

The babies are randomly divided into two equal sized groups.
One group is periodically given a 'magic formula' drink consisting of cow pus, rotting flesh of a sacrificed baby, aluminum beer cans and embalming fluid.
And the other group is given equal opportunities for life except for no 'magic formula'.

• After observing this village for 6 years, which group will have the largest population?
  
• Which group would have the best health?

The following links will answer what ingredients modern vaccines contain

The making of vaccines: from page 95 of:
IMMUNIZATION The Reality Behind the Myth, by Walene James

1. A young calf has his belly shaved.
2. Many slashes are made in the skin.
3. A prior batch of smallpox vaccine is dropped into the slashes and allowed to fester over a period of days.
4. During this time, the calf stands in a headstock so that he can't lick his belly. The calf then is led out of the stock to a table where he is strapped down.
5. His belly scabs and pus are scraped off and ground into a powder.
6. That powder is the next batch of small pox vaccine.

Source for this book: VacLib products

[Keep in mind that the 'original' vaccine was probably made by taking smallpox waste matter (pus) from a human suffering from smallpox and rubbing this into the belly of a calf. The smallpox vaccine may contain a live smallpox virus, or as the newspapers today cautiously describe it, "a near relative" of smallpox.]