Childhood immunisation has stalled in the past year, mainly due to increased global conflict, with the number of children receiving no vaccines increasing to 14.5 million in 2023 – up from 13.9 million in 2022.

There has also been an almost threefold increase in measles cases in the past year – a sign of inadequate vaccinations – including in conflict-ridden Sudan, Yemen and Afghanistan.

This is according to the latest global immunisation estimates for 2023 based on data from 194 countries, that was released on Monday (15 July) by the World Health Organization (WHO) and UNICEF.

Around 55% of the “zero-dose” children “live in countries that have some aspect of the country that is fragile, conflict-affected or a vulnerable setting”, according to Dr Kate O’Brien, WHO Director of Immunization. These areas only contributed to 28% of global births.

Fragile and vulnerable settings usually refer to situations where humanitarian crises, armed conflicts and natural disasters prevail.

Sudan’s vaccination rate plunged from 75% in 2022 to 57% last year, with the result that about 700,000 children received no vaccines. This represents over 43% of all unvaccinated children in the region, noted Dr Ephrem Lemango, UNICEF’s global head of immunisation, at a media briefing to launch the data.

Palestine has been unable to document immunisation figures since September 2023 because of Israeli attacks in the region. However, Ukrainian immunisation has improved despite Russian attacks.

“Children who are living in [conflict-ridden and vulnerable] settings also lack security, lack nutrition, lack healthcare, and are most likely, as a result of those things, to die from a vaccine-preventable disease if they get it,” O’Brien told the briefing.

The needle also did not move for basic immunisation – the global marker for this being that children get three doses of the DTP combination vaccine for diphtheria, tetanus and pertussis (whooping cough).

While 84% of children – 108 million – got three DTP vaccinations in 2023, this was the same figure as the previous year. 

The WHO’s conflict-ridden Middle East and North Africa region recorded a 4% decline DTP vaccination.

Aside from the zero-dose children, 6.5 million children did not get all three doses of DTP. 

The zero-dose children and the under-immunized children amounted to 21 million kids in 2023 – 2.7 million more than before the pandemic, when there were 18.3 million of these un- or under-vaccinated children, O’Brien noted.

The COVID-19 pandemic significantly disrupted childhood vaccinations, one of the most powerful global weapons to protect babies and young children from serious illness and death.

UNICEF, the WHO and Gavi, the global vaccine alliance, united last year with “The Big Catch-up” campaign to regain lost ground. 

Twenty-five of the 35 low-income countries targeted have either recovered to pre-pandemic levels or have improved their coverage in the past year.

Bright spots: HPV vaccine expansion

There was a 3% reduction in zero-dose children in the Americas, largely thanks to an impressive recovery in Brazil.

Africa reduced its zero-dose children by 1% (to 6.7 million), with Chad, South Sudan,  Mauritania, Tanzania and Cameroon singled out for their improvements. Ethiopia also improved its immunisation following a reduction in conflict in Tigray.

Global coverage of the human papilloma virus (HPV) vaccine to prevent cervical cancer jumped by 7% last year, with 27% of girls receiving the first dose of HPV vaccine.

“This increase was largely driven by really strong introductions of HPV vaccine in large countries, including Bangladesh, Indonesia and Nigeria, which were supported by Gavi,” said O’Brien.

However, China, India and Russia have yet to introduce the HPV vaccine.

In addition, most countries are only vaccinating girls although males are both carriers of the virus that can be passed on to females during sex, and can be affected by penile and throat cancers caused by HPV.

O Brien explained that while the WHO recommends that both girls and boys get the HPV vaccine, “the priority, especially in the introduction phase of vaccine, is for provision of the vaccine to girls”, as the largest disease burden relates to cervical cancer.

“Once countries have well functioning programs, then an advancement in the program would be to consider moving including boys.”

Rising measles cases

“Immunization stands as one of humanity’s greatest achievements, and it has saved over 154 million lives over the past 50 years, with measles vaccination alone responsible for about 60% of this,” noted Dr Ephrem Lemango, UNICEF’s global head of immunisation.

“And yet, measles outbreaks continue to rise as measles vaccination coverage stalls. For example, the world saw over 300,000 confirmed measles cases in 2023 which is an almost threefold increase compared to what we had in 2022.”

Lemango noted that only 83% of children received their first measles vaccine dose, and 74% were fully protected by a second measles vaccine.

Afghanistan, Angola and Yemen had the lowest measles vaccination rates. However, countries without conflicts such as Indonesia and Pakistan also had low rates. Some of the setbacks related to countries’ weak economies following COVID, said O’Brien.

“Over the past five years, about 103 countries with inadequate vaccine coverage saw measles outbreaks,” said Lemango. “[This] contrasted sharply with the remaining 91 countries, where coverage exceeds 90% and no outbreaks occurred.”

“Measles outbreaks are the canary in the coalmine, exposing and exploiting gaps in immunization and hitting the most vulnerable first,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General.

“This is a solvable problem. Measles vaccine is cheap and can be delivered even in the most difficult places. WHO is committed to working with all our partners to support countries to close these gaps and protect the most at-risk children as quickly as possible.”

Vaccine hesitancy from COVID misinformation

A rising lack of confidence in vaccines – also a COVID-19 setback  – has affected uptake of routine childhood vaccinations.

“During the pandemic, we all experienced a huge amount of misinformation and disinformation, and this is continuing to reverberate in many countries, and is actually resulting in deaths,” said O’Brien. 

“It’s resulting in children and adults and adolescents not getting vaccinated when they are recommended to be vaccinated, and is causing harm. Misinformation and disinformation, are a health threat themselves, and they actually cost people their lives.”

“The latest trends demonstrate that many countries continue to miss far too many children,” said UNICEF Executive Director Catherine Russell.

“Closing the immunization gap requires a global effort, with governments, partners, and local leaders investing in primary healthcare and community workers to ensure every child gets vaccinated, and that overall healthcare is strengthened.”

Image Credits: Gavi, Gavi.