He spoke about his worries as the Bill & Melinda Gates Foundation pledged $150 million (£110m) to the Coalition for Epidemic Preparedness Innovation (CEPI).
The donation will be used in the fight against Covid-19 as well as any preparation needed for future pandemics.
Speaking about the work done by CEPI, Gates explained: "As the world responds to the challenge of a rapidly evolving virus, the need to deliver new, lifesaving tools has never been more urgent.
"Our work over the past 20 years has taught us that early investment in research and development can save lives and prevent worst-case scenarios. Five years ago, following the Ebola and Zika epidemics, our foundation helped launch CEPI.
"Today, we’re increasing our commitment and pledging an additional $150 million to help CEPI accelerate the development of safe and effective vaccines against emerging variants of the coronavirus and to prepare for, and possibly even prevent, the next pandemic.”
CEPI is on a mission to ensure that the time taken to produce vaccines is within a 100 day window.
According to the Independent, Mr Gates took the opportunity to urge governments to contribute in order to prevent the spread of future pandemics which could include fatalities far worse than the Covid pandemic.
When the Covid-19 pandemic began, CEPI responded immediately, building one of the world’s largest and most diverse portfolios of Covid-19 vaccine candidates—14 in all, including six of which continue to receive funding, and three of which have been granted emergency use listing by the World Health Organization (WHO).
The Gates Foundation founded CEPI in 2017 alongside Wellcome, the World Economic Forum as well as backing from Norway and India. This came following the impact of the Ebola epidemic.
Dr. Jeremy Farrar, director of Wellcome said: "Our new commitment of $150 million recognizes the enormous potential CEPI has to protect lives against emerging infectious diseases.
"The effects of Covid-19 have been sobering. We urge leaders to provide their support and ensure that CEPI reaches its funding target. It is in the world’s collective interest to avoid repeating mistakes and to help future generations prevent epidemics."
In a blog post, Gates explained where things have gone wrong when it comes to Covid, writing: "Creating new vaccines isn’t enough. We also have to make sure that everyone who can benefit from vaccines has access to them, and that’s where the world has collectively failed in its response to COVID.
"While at least 9 billion doses were distributed in the past year, less than one percent went to people in low-income countries.
"It doesn’t make sense that so many people at lower risk of infection in wealthier countries got vaccinated before we reached the most vulnerable people, including the elderly, those with underlying medical conditions, and healthcare workers.
"We need to do better the next time the world faces a pathogen that has the potential to spark a pandemic."