United Nations agencies and the GAVI vaccine alliance said on Friday that 80 million children in at least 68 countries may be at risk of diphtheria, measles and polio because routine immunization efforts have been thrown into disarray by travel restrictions, delivery delays, and parents' fear of leaving home.
"If we neglect the supply chains and immunization infrastructure that keep these programs running, we also risk harming our ability to roll out the COVID-19 vaccine that represents our best chance of defeating this pandemic", Berkley told reporters via a World Health Organization conference call.
Measles and polio immunisation campaigns have been particularly badly hit, with measles campaigns suspended in 27 countries and polio campaigns in 38.
"We can not let our fight against one disease come at the expense of long-term progress in our fight against other diseases", said Henrietta Fore, UNICEF executive director.
Meanwhile health workers have been redeployed to treat COVID-19 patients, and some parents have been unable to get their children to vaccination sites due to movement restrictions.
She said countries needed to step up efforts to track unvaccinated children, and find innovative solutions, as Laos has done by immunising children in supermarkets.
"As the world comes together to create a lifesaving vaccine for Covid-19, we must not forget those that already exist".
London is hosting a virtual Global Vaccines Summit on June 4 where GAVI is seeking $7.4 billion for 2021-2025 to immunize an additional 300 million children.
The novel coronavirus has killed at least 332,000 people since the outbreak first emerged in China last December, according to a tally from official sources compiled by AFP.
"As the world passes five million recorded cases of COVID-19, we recognise the importance of building national unity and global solidarity to learn from each other and suppress the virus everywhere", Tedros said.