Vaccines both good and bad?

[Cyberman]

I see you're worried about harmful substances entering your body. Excellent. I applaud your caution. Just fyi, do you realise how much radiation you're exposed to on a daily basis?

Cosmic Radiation
The sun and stars send a constant stream of cosmic radiation to Earth, much like a steady drizzle of rain. Differences in elevation, atmospheric conditions, and the Earth's magnetic field can change the amount (or dose) of cosmic radiation that we receive.

Terrestrial Radiation
The Earth itself is a source of terrestrial radiation. Radioactive materials (including uranium, thorium, and radium) exist naturally in soil and rock. Essentially all air contains radon, which is responsible for most of the dose that Americans receive each year from natural background sources. In addition, water contains small amounts of dissolved uranium and thorium, and all organic matter (both plant and animal) contains radioactive carbon and potassium. Some of these materials are ingested with food and water, while others (such as radon) are inhaled. The dose from terrestrial sources varies in different parts of the world, but locations with higher soil concentrations of uranium and thorium generally have higher doses.

Internal Radiation
All people have internal radiation, mainly from radioactive potassium-40 and carbon-14 inside their bodies from birth and, therefore, are sources of exposure to others. The variation in dose from one person to another is not as great as that associated with cosmic and terrestrial sources.

My advice would be to find a disused mineshaft, the deeper the better, and build a bunker there. Make sure the walls are at least twenty feet thick, solid concrete, airtight, and lined with lead. Stay away from all sources of food and water. That way you're not only protected from the external radiation, you yourself will pose no contamination risk to anyone else.