There is a need for Western Pacific countries to maintain high coverage of measles vaccination and to increase surveillance of cases at international borders, the WHO Regional Director for the Western Pacific, Dr. Saia Ma’u Piukala urged, citing a 255% increase of measles cases from 2022 to 2023 in Western Pacific countries.

Measles cases went up 255% from 2022 to 2023 in the Western Pacific Region, a total of 5044 cases, compared to lower levels of measles infections in 2021 with 1080 cases, and 2022 with 1422 cases. This increase was caused by gaps in vaccination coverage and disease surveillance, and travel of people from countries experiencing outbreaks.

WHO Regional Director for the Western Pacific, Dr. Saia Ma’u Piukala urged, “Anytime there’s measles in a community, it is a threat. Even countries that have achieved elimination can’t relax. They have to maintain high coverage of measles vaccination and strong systems for picking up cases that get imported through international travel. Without this, measles transmission can become re-established."

The World Health Organization Regional Office for the Western Pacific said the declines in vaccination coverage in several Western Pacific countries during the COVID-19 pandemic, ongoing measles outbreaks in the Philippines, and persistent endemic measles transmission in Malaysia, all pose a threat of measles resurgence in the region for 2024 and 2025.

"If measles is imported into communities where vaccination coverage is below 95%, the risk of outbreaks increases."

"Around 3.6 million children in the Western Pacific region missed their routine immunisations during 2020-2022. The resurgence of measles worldwide increases the risk of importation to countries throughout the Western Pacific, including those where measles had previously been eliminated."

Measles is one of the most infectious diseases on earth, spreading easily when an infected person breathes, coughs or sneezes. A single person infected with measles can potentially infect 12 to 18 additional people, and the disease can lead to severe complications and death. However, it is almost entirely preventable through two doses of measles vaccine.

From 2000 to 2022, measles vaccinations prevented 57 million measles deaths worldwide.

Pacific countries to eliminate measles cases

Twenty-one Pacific island countries and areas are currently on track to eliminate measles and rubella by 2025. After a measles outbreak in the Pacific in 2019, efforts were taken to improve vaccination coverage and surveillance for the disease. Since early 2020, there have been no ongoing transmission of measles or rubella in the Pacific island countries.

Through regularly conducted vaccination campaigns and catch-up activities, great work has been done to close immunisation gaps in the Pacific. The WHO is working with Tonga, Cook Islands, Kiribati, Samoa, Solomon Islands, and Vanuatu, to expand serology and molecular testing for measles and rubella in laboratories in the Pacific.

“The Western Pacific must not forget the bitter lessons we have learned from previous measles resurgences in the Region,” says Dr Saia Ma’u Piukala. “Countries must keep working to reach every child with lifesaving vaccines, strengthen surveillance systems, encourage health workers to stay vigilant and educate people about the importance of checking that their vaccinations are up-to-date so we can avoid a resurgence in the future."

Meanwhile, the Western Pacific region office said that additional equipment and training are due in the coming months.

Supporting countries to reduce immunisation gaps, increase surveillance

From 2022 to 2023, eleven countries in the Western Pacific, including Fiji, Kiribati, Marshall Islands, the Federated States of Micronesia, Mongolia, Palau, Papua New Guinea, the Philippines, Samoa, Solomon Islands and Viet Nam, conducted nationwide measles and rubella vaccination campaigns or catch-up vaccination activities.

Cambodia and the Lao People’s Democratic Republic are planning nationwide measles and rubella vaccination campaigns this year. However, more needs to be done to ensure countries in the region maintain robust immunity through vaccination, especially among populations that are harder to reach and people who are travelling.

Strong early warning and disease surveillance systems with complete case investigations are also vital for health authorities to quickly find and confirm potential measles or rubella cases before they become a larger outbreak.

Meanwhile, the WHO regional office for Western Pacific urged the public to ensure that they are fully protected with two doses of measles-containing vaccine, especially for travellers who, if unvaccinated, could expose young children and other vulnerable people in communities to which they are traveling to infection. It is also vital for health workers to ensure their patients are fully vaccinated and they can recognise and report possible cases of measles to prevent outbreaks.