Measles is highly contagious and almost entirely preventable through vaccination. But the Covid pandemic led to a decline in vaccine coverage for the disease.

The WHO in its latest statement said, "There is now an imminent threat of measles spreading to different regions around the world," as Covid-19 led to a steady decline in vaccination coverage and weakened surveillance of the disease.

The WHO said nearly 40 million children missed vaccine doses last year for measles. Whereas in July, the UN said 25 million children have missed out on routine immunizations against diseases, including diphtheria, largely because the coronavirus disrupted routine health services or triggered vaccine misinformation.

Measles is one of the most contagious human viruses and is almost entirely preventable through vaccination. However, it requires 95% vaccination coverage to prevent community outbreaks.

In 2021, officials said there were about nine million measles infections and 128,000 deaths worldwide.

The WHO and the US Centers for Disease Control and Prevention (CDC) said continued drops in vaccination, weak disease surveillance and delayed response plans due to Covid-19, and ongoing outbreaks in more than 20 countries, mean that "measles is an imminent threat in every region of the world."

Measles can be dangerous, especially for babies and young children. Measles typically begins with a high fever, cough, runny nose and red, watery eyes.

Tiny white spots may appear inside the mouth two to three days after symptoms begin, according to US CDC. Three to five days after symptoms begin, a rash breaks out. It usually begins as flat red spots that appear on the face at the hairline and spread downward to the neck, trunk, arms, legs, and feet. Small raised bumps may also appear on top of the flat red spots.

The Centre has asked states to consider administering one additional dose of Measles and Rubella vaccines to all children, aged 9 months to 5 years in vulnerable areas.