Measles Vaccination and Prevention: Protecting Your Child and Community
This is the second article in our three-part series on measles. In this installment, we explore the measles vaccine, current recommendations, and why vaccination remains our best defense against this highly contagious disease.
The Vaccine That Changed History
Before the introduction of the measles vaccine in 1963, measles was an almost universal childhood experience in the United States. Each year, approximately: • 3-4 million people were infected • 48,000 were hospitalized • 1,000 developed encephalitis (brain inflammation) • 400-500 died from measles complications
Today, thanks to widespread vaccination, measles cases have decreased by more than 99% in the United States, and the disease was declared eliminated (absence of continuous transmission for 12+ months) in 2000. However, outbreaks still occur when the virus is imported from other countries and spreads among unvaccinated populations.
Understanding Measles Vaccines
Two types of measles vaccines are available in the United States, both containing live but weakened (attenuated) measles virus:
Measles, Mumps, and Rubella (MMR) Vaccine Two MMR vaccines are currently licensed in the U.S.: • M-M-R II (manufactured by Merck) • PRIORIX (manufactured by GlaxoSmithKline)
These vaccines are approved for people 12 months and older. Both products are considered equivalent and can be used interchangeably.
Measles, Mumps, Rubella, and Varicella (MMRV) Vaccine • ProQuad (manufactured by Merck) • Licensed for children 12 months through 12 years of age • Combines the MMR vaccine with the chickenpox (varicella) vaccine
The single-antigen measles vaccine is no longer available in the United States.
Current Vaccination Recommendations
The American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC) recommend:
Routine Vaccination Schedule • First dose: 12-15 months of age • Second dose: 4-6 years of age (before kindergarten)
The minimum interval between doses is 28 days for MMR and 90 days for MMRV.
Special Circumstances For infants traveling internationally or during community outbreaks: • Infants 6-11 months should receive one dose of MMR before departure • This early dose does NOT count toward the routine two-dose series • MMRV should NOT be given to children under 12 months
Catch-up Vaccination If your child has missed the recommended ages: • Children over 12 months who haven't received any doses should get their first dose as soon as possible • The second dose can be given as soon as 28 days after the first dose
How Well Does the Vaccine Work?
The measles vaccine is remarkably effective: • One dose is approximately 93% effective at preventing measles • Two doses are approximately 97% effective • Even in the small percentage of vaccinated people who do get measles, the disease is typically milder with fewer complications
A small percentage of people (up to 7%) may not respond to their first dose of vaccine (primary vaccine failure). This is why a second dose is recommended for everyone.
What to Expect After Vaccination
Most children who receive the measles vaccine have no side effects. When side effects do occur, they're usually mild and may include: • Soreness at the injection site • Fever (occurring in about 5-15% of recipients, usually 7-12 days after vaccination) • Mild rash (about 5% of recipients) • Temporary pain and stiffness in the joints (more common in adolescents and adults)
More serious reactions are rare. Seizures, often associated with fever, can occur after MMRV vaccine and are more common in children aged 12-23 months compared to those receiving separate MMR and varicella vaccines. For this reason, providers should discuss the benefits and risks of both vaccination options with parents.
Who Should NOT Receive the Measles Vaccine
While measles vaccination is safe for most people, certain groups should not receive it:
• People with severe allergic reactions to a previous dose or to components of the vaccine • Pregnant women (pregnancy should be avoided for at least 28 days after vaccination) • People with severe immunodeficiency, including:
Patients with severe primary immunodeficiency
Patients receiving treatment for leukemia or lymphoma
Patients on high-dose immunosuppressive therapy
People with severe HIV infection (defined as CD4+ T-lymphocyte percentage <15% for age ≤5 years, or CD4+ T-lymphocyte percentage <15% or count <200 lymphocytes/mm³ for age >5 years) • People who have recently received immune globulin products (timing varies) • Moderately or severely ill people (vaccination should be postponed until recovery)
If your child has any of these conditions, talk with your healthcare provider about the best approach to protection.
Building Community Immunity
Measles is so contagious that we need very high vaccination rates—92-94%—to prevent its spread within communities. This concept, known as "community immunity" or "herd immunity," is especially important for protecting:
• Infants too young to be vaccinated • People with medical conditions that prevent them from being vaccinated • The small percentage of people for whom the vaccine doesn't work
When vaccination rates fall below the community immunity threshold, outbreaks can occur. This has happened in several areas of the United States in recent years, typically in communities with lower vaccination rates.
Global Context: The Worldwide Fight Against Measles
While great progress has been made, measles remains a significant global health concern: • Worldwide, measles deaths decreased by 94% between 2000 and 2020 • As of 2021, 76 countries had achieved or maintained measles elimination status • However, the COVID-19 pandemic disrupted vaccination services worldwide, leading to decreased measles vaccine coverage (from 86% in 2019 to 81% in 2021) • This decline, coupled with reduced surveillance, has increased the risk of outbreaks
When travelers from the United States visit countries where measles is common, they can become infected and bring the virus back home, potentially sparking outbreaks in unvaccinated communities.
Vaccine Storage and Administration
The effectiveness of the measles vaccine depends on proper storage and handling: • MMR vaccines must be stored according to manufacturer specifications • MMRV vaccine must be stored frozen between -58°F and +5°F • Improperly stored vaccine may fail to protect against measles
Vaccines are administered as a 0.5 mL dose, either subcutaneously or intramuscularly, depending on the specific formulation.
Evidence of Immunity to Measles
In certain situations (e.g., college admission, healthcare employment), documentation of immunity to measles may be required. Acceptable evidence includes:
Documentation of age-appropriate vaccination:Preschool-aged children: 1 dose School-aged children (K-12): 2 doses Adults not at high risk: 1 dose High-risk adults (healthcare workers, college students, international travelers): 2 doses
Laboratory evidence of immunity
Laboratory confirmation of previous measles infection
Birth before 1957 (presumed to have had measles naturally)
In Our Next Installment
In the final part of our series, we'll discuss what happens when measles cases occur in communities, including how to respond to exposures, treatment options, and how healthcare providers and public health officials work together to contain outbreaks.
Have questions about the measles vaccine or your child's vaccination status? Contact your healthcare provider to ensure your family is protected. Remember, staying up-to-date on recommended vaccinations is one of the most important ways to protect your child's health.
