Over the last 20 years GAVI and its partners have vaccinated more than 760 million children in 70 countries, saving the lives of more than 13 million.
But in celebrating World Immunisation Week, the worry is that millions of children would be missing out on vaccines against measles, diphtheria and polio.

Even before the coronavirus pandemic, measles, polio and other vaccines were out of reach for 20 million children below the age of one every year.

Given the current disruptions, the UN Children's Fund (UNICEF) has warned that this could lead to disastrous outbreaks in 2020 and well beyond.
GAVI estimates that at least 21 low- and middle-income countries, are already reporting vaccine shortages as a result of border closures and disruptions to travel.

So far, 14 vaccination campaigns supported by GAVI against polio, measles, cholera, human papillomavirus, yellow fever and meningitis have been postponed, which would have immunised more than 13 million people.
The Director-General of the World Health Organisation (WHO), Dr Tedros Adhanom Ghebreyesus, said this week: "The tragic reality is that children will die as a result."
GAVI has set an ambitious goal to immunise 300 million more children with 18 vaccines by 2025, and to attain this the organisation is looking to raise US$7.4 billion in its upcoming third replenishment that has been scheduled for June.

Dr Tedros said: "We call on the global community to ensure GAVI is fully funded for this life saving work.
"This is not a cost, it's an investment that pays a rich dividend in lives saved.
"Just as immunisation has been disrupted in some countries, so have services for many other diseases that afflict the poorest and most vulnerable people – including malaria.
"Immunisation is one of the greatest success stories in the history of global health," he said, adding: "More than 20 diseases can be prevented with vaccines."
Dr Richard Sezibera, a former Minister of Health in Rwanda, and a long-serving member of the GAVI Board, explained in an Op-Ed for the Africa Briefing website earlier this month: "Now more than ever, the need to bring together public and private sectors in strengthening our healthcare systems is being shown.

"With GAVI, this kind of collaboration has been going on for 20 years and is still going strong with the shared goal of creating equal access to new and underused vaccines for children and persons all around the world."
Dr Sezibera, who is also Chair of GAVI's Programme and Policy Committee, said this year's replenishment was "seeking to build on the historic gains it has made with governments and other partners".  

He added: "We will need to step up with even more.
"Commitments are needed towards increased domestic financing and for recognition of the critical role of vaccines to primary healthcare in Africa, at least for the next period of 2021-2025."

GAVI said that immunisation campaigns required "a coordinated approach that factors in the unique challenges of each country".
It added: "For example, in areas with densely populated urban settlements, there may be challenges with communicating the importance of vaccines, so social mobilisation activities are required.
"Conversely, many GAVI-supported countries have very remote regions that demand a new approach to vaccine delivery, like using autonomous drones to efficiently deliver medical supplies."

The alliance said it was making "health system strengthening grants more flexible to allow countries to reallocate funding towards their COVID-19 response, as well as working with our partners to continue immunisation campaigns where possible".

"The immunisation infrastructure that GAVI has helped build over the past two decades is also being used to help fight the pandemic," the organisation said.