For their sake. For your sake. Vaccinate.
Vaccines are safe and effective. Vaccine-preventable diseases are at an all time low thanks to more people being vaccinated, saving lives and millions of dollars in health care costs, but this doesn't mean the diseases have disappeared. Many viruses and bacteria are still circulating. This is why it is important for everyone to receive all of the recommended immunizations on time.
Most vaccine-preventable diseases are caused by germs called viruses or bacteria. Vaccines to help prevent these diseases generally contain weakened or dead viruses or bacteria specific to the disease.
Vaccines help your body recognize and fight these germs and protect you each time you come in contact with someone who is sick with any of these diseases. - MO Dept of Health