John Oliver talks possibility of another pandemic on season premiere of 'Last Week Tonight'

It was the first episode since his last show, which aired in November, and he covered a lot of ground, including former President Donald Trump's second impeachment trial, the Covid-19 vaccine rollout, and a stark warning about the possibility of another pandemic.

"If we're not very careful, the next pandemic could be even worse," Oliver said, adding, "Now might be the most important time talk about this because scientists attempted to warn us about the 'next' pandemic long before the current one hit, and we didn't really listen."

Oliver played a clip from a 2004 "60 Minutes" segment about the SARS epidemic which cautioned that another, more deadly, pandemic was on the horizon.

He discussed deforestation, urbanization, wet markets and animals as possible causes of the next pandemic, and suggested ways to spot potential health hazards ahead of time.

He also warned usto not get "complacent" with the pandemic we are currently in.

"So for the good of future generations, and in all likelihood, us in a few years' time, we really need to remember how we feel right now and invest accordingly, because the truth is you never know where the next pandemic is going to come from," Oliver said.