Measles is a highly contagious, serious viral disease. Before the introduction of measles vaccine in 1963 and widespread vaccination, major epidemics occurred approximately every two to three years and caused an estimated 2.6 million deaths each year.
An estimated 128 000 people died from measles in 2021 – mostly children under the age of five years, despite the availability of a safe and cost-effective vaccine.
Measles is caused by a virus in the paramyxovirus family, and is normally passed through direct contact and the air. The virus infects the respiratory tract, then spreads throughout the body, causing severe disease, complications and even death.
Accelerated immunization activities by countries, WHO, the Measles & Rubella Partnership (formerly the Measles & Rubella Initiative), and other international partners successfully prevented 56 million deaths between 2000-2021. Vaccination decreased measles deaths from 761 000 in 2000* to 128 000 in 2021.
Effects of the COVID-19 pandemic
The COVID-19 pandemic led to setbacks in surveillance and immunization efforts. The suspensions of immunization services and declines in immunization rates and surveillance across the globe left millions of children vulnerable to preventable diseases like measles.
No country is exempt from measles, and areas with low immunization encourage the virus to circulate, increasing the likelihood of outbreaks and putting all unvaccinated children at risk.
We must regain progress and achieve regional measles elimination targets, despite the COVID-19 pandemic. Immunization programs should be strengthened within primary healthcare, so efforts to reach all children with two measles vaccine doses should be accelerated. Countries should also implement robust surveillance systems to identify and close immunity gaps.
Signs and symptoms
The first sign of measles is usually high fever, beginning about 10 to 14 days after exposure to the virus and lasting four to seven days. A runny nose, cough, red and watery eyes, and small white spots inside the cheeks can develop in the initial stage. A rash erupts after several days, usually on the face and upper neck. The rash spreads over about three days, eventually reaching the hands and feet, and lasts five to six days before fading. On average, the rash occurs 14 days after exposure to the virus (within a range of seven to 18 days).
Most measles-related deaths are caused by disease-related complications. Serious complications are more common in children under five years, or adults over 30 years of age. The most serious complications include blindness, encephalitis (an infection that causes brain swelling), severe diarrhoea and related dehydration, ear infections, or severe respiratory infections such as pneumonia. Severe measles is more likely among malnourished young children, especially those with insufficient vitamin A or weakened immune systems from HIV/AIDS or other diseases.
Who is at risk?
Any non-immune person (not vaccinated or vaccinated but did not develop immunity) can become infected. Unvaccinated young children and pregnant persons are at highest risk of severe measles complications.
Measles is still common, particularly in parts of Africa and Asia. The overwhelming majority of measles deaths occur in countries with low per capita incomes or weak health infrastructures that struggle to reach all children with immunization.
Damaged health infrastructure and health services in countries experiencing or recovering from a natural disaster or conflict interrupt routine immunization and overcrowding in residential camps increases the risk of infection.
Measles is one of the world’s most contagious diseases, spread by close or direct contact with infected nasal or throat secretions (coughing or sneezing). One person infected by measles can infect nine out of 10 of their unvaccinated close contacts.
The virus remains active and contagious in the air or on infected surfaces for up to two hours. It can be transmitted by an infected person from four days prior to the onset of the rash to four days after the rash erupts.
Measles outbreaks can result in severe complications and deaths, especially among young, malnourished children. In countries close to measles elimination, cases imported from other countries remain an important source of infection.
No specific antiviral treatment exists for measles.
Severe complications from measles can be reduced through supportive care with good nutrition, adequate fluid intake and dehydration treatment with WHO-recommended oral rehydration solution, which replaces fluids and essential elements lost through diarrhoea or vomiting. Antibiotics should be prescribed to treat eye and ear infections, and pneumonia.
All children diagnosed with measles should receive two doses of vitamin A supplements, given 24 hours apart. This restores low vitamin A levels during measles that occur even in well-nourished children and helps prevent eye damage and blindness. Vitamin A supplements may also reduce the number of measles deaths.
Routine measles vaccination, combined with mass immunization campaigns in countries with high case rates are crucial for reducing global measles deaths. The measles vaccine – in use for about 60 years – is safe, effective and inexpensive. It costs approximately one US dollar to immunize a child against measles.
The measles vaccine is often incorporated with rubella and/or mumps vaccines. It is equally safe and effective in the single or combined form. Combining vaccines slightly increases the cost, but allows for shared delivery and administration costs.
In 2021, 71% of children received both doses of the measles vaccine, and about 81% of the world’s children received one dose of measles vaccine by their first birthday, the lowest since 2008. Two doses of the vaccine are recommended to ensure immunity and prevent outbreaks, as not all children develop immunity from the first dose.
Approximately 25 million infants missed at least one dose of measles vaccine through routine immunization in 2021.
In 2020, WHO and global stakeholders endorsed the Immunization Agenda 2021–2030. The Agenda aims to achieve the regional targets as a core indicator of impact, positioning measles as a tracer of a health system’s ability to deliver essential childhood vaccines.
WHO published the Measles and rubella strategic framework in 2020, establishing seven necessary strategic priorities to achieve and sustain the regional measles and rubella elimination goals.
During 2000–2021, supported by the Measles & Rubella Initiative (now the Measles and Rubella Partnership) and Gavi, measles vaccination prevented an estimated 56 million deaths; mostly in the WHO African Region and Gavi-supported countries.
Without sustained attention, hard-fought gains can easily be lost. Where children are unvaccinated, outbreaks occur. Based on current trends of measles vaccination coverage and incidence, the WHO Strategic Advisory Group of Experts on Immunization (SAGE) concluded that measles elimination is under threat, as the disease resurged in numerous countries that achieved, or were close to achieving, elimination.
WHO continues to strengthen the Global Measles and Rubella Laboratory Network (GMRLN) to ensure timely diagnosis of measles and track the virus’ spread to assist countries in coordinating targeted vaccination activities and reduce deaths from this vaccine-preventable disease.
The IA2030 Measles & Rubella Partnership
The Immunization Agenda 2030 Measles & Rubella Partnership (M&RP) is a partnership led by the American Red Cross, United Nations Foundation, Centers for Disease Control and Prevention (CDC), Gavi, the Vaccines Alliance, the Bill and Melinda French Gates Foundation, UNICEF and WHO, to achieve the IA2030 measles and rubella specific targets. Launched in 2001, as the Measles and Rubella Initiative, the revitalized Partnership is committed to ensuring no child dies from measles or is born with congenital rubella syndrome. The Partnership helps countries plan, fund and measure efforts to permanently stop measles and rubella.