Who Is at Risk From Unvaccinated Kids?

Immunization protects you and your child from vaccine-preventable diseases as well as everyone around you. This is because herd immunity dictates that if most people are immune to a disease, the risk of community transmission is diminished in addition to the incidence of disease and illness.

Even people who refuse vaccination or don't believe in herd immunity benefit from community-wide vaccination as the risk of infection decreases. However, if a large sector of the population does not get the recommended vaccines, diseases thought to be eliminated can begin to return. This is the case with measles, which was declared eliminated in the United States in 2000 but is now recurring in pockets throughout the country.

Myths and Misconceptions

One of the classic myths among anti-vaccine proponents is that unvaccinated children pose no risk to the public because most people are vaccinated. The underlying assumption is that if harm is done, only the unvaccinated individual will be affected.

As the recent measles outbreak has shown, this is not the case. In fact, as the spread of measles continues in the United States, others who might otherwise be safe are beginning to be affected.

This includes the following:

• Infants too young to be vaccinated are often exposed at hospitals or healthcare provider's offices where someone with measles is seeking care.
• People with weak immune systems are vulnerable to infection, as happened in Pittsburgh in 2018 when a college student was believed to have exposed around 100 people with cancer to measles.
• Healthcare workers are often placed at needless risks, such as occurred in 2013 when a healthcare provider developed measles encephalitis during the large outbreak in Fort Worth.

Outbreaks like these affect everyone in a community, even those who do not get sick.

Children at Risk

Among the groups who are most at risk of the anti-vaccine movement are infants and children who are too young to be vaccinated. These are often children of parents who fully intend to get them vaccinated but simply can't because of their age.

This is an especially big problem with pertussis (whooping cough) as infants don't begin to achieve full protection from the DTaP vaccine until their third shot at 6 months. In the California pertussis outbreak of 2010, 10 infants died, nine of whom were less than 2 months old.

Among some of the other vaccine-preventable diseases that younger children may get during gaps in their vaccination schedules:

• Influenza: Children don't get their first dose of the influenza vaccine until they are 6 months old, and a second dose is delivered a month later.
• Measles: Children don't get their first dose of the measles mumps rubella (MMR) vaccine until they are 12 months old and aren't fully protected until they get their second dose at 4 to 6 years of age.
• Chickenpox: Chickenpox, like measles, is scheduled so that children get their first dose of the varicella vaccine at 12 months and the second dose at 4 to 6 years of age.

Younger children are also at risk for polio, rubella, and mumps until they are old enough to be vaccinated.

Immune Deficiency Risks

Children and adults with weak immune systems may be at risk of vaccine-preventable diseases for different reasons. Some are immunocompromised and cannot receive certain vaccines (particularly live vaccines) because the vaccines can end up causing illness. Others are unable to achieve the same immune protection following vaccination due to an underlying immune deficiency.

In either instance, the lack of an intact immune system places these individuals at greater risk of infection and illness than those with a robust immune response.

There are at least 180 different primary immune deficiency disorders (rare, genetic disorders that impair the immune response) and many secondary ones (like HIV, organ transplants, and cancers like lymphoma and leukemia) that can place a child at an increased risk of infection.

One example involved a toddler with acute lymphoblastic leukemia (ALL). According to the CDC report, a 4-year-old child with ALL developed complications from a chickenpox infection 22 days after exposure despite being vaccinated against the disease. She died several days later due to multi-organ failure.

Allergy Risks

There are also situations where a child may be old enough to be vaccinated and has a strong immune system but still can't get some or all of their vaccines.

Although uncommon, a life-threatening allergic reaction may preclude some children from getting or completing a vaccine course. For example, if a child has had a life-threatening reaction to the antibiotic neomycin, they would likely be allergic to the polio vaccine, chickenpox vaccine, and MMR vaccine.

Unlike children whose parents refuse them vaccines, these kids have true medical exemptions to getting vaccinated.

Summary

Vaccines are effective. Even so, an aversion to vaccines places the wider community at risk of diseases that should be fully under control.

While most children in the United States are vaccinated, data from the CDC suggests that nearly three in seven do not complete the 7-vaccine series recommended by age 3. That leaves many kids under-protected against diseases they might otherwise avoid.

If you are unsure whether you or your child needs vaccines or vaccine boosters, speak with your healthcare provider.

Vaccinations Healthcare Provider Discussion Guide

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