The video platform said it would now ban any content with claims about COVID-19 vaccines that contradict consensus from local health authorities or the World Health Organization.
YouTube said in a blog post that this would include removing claims that the vaccine will kill people or cause infertility, or that microchips will be implanted in people who receive the vaccine.
A YouTube spokesman told Reuters that general discussions in videos about "broad concerns" over the vaccine would remain on the platform.
Conspiracy theories and misinformation about the new coronavirus vaccines have proliferated on social media during the pandemic, including through anti-vaccine personalities on YouTube and through viral videos shared across multiple platforms.
Although drugmakers and researchers are working on various treatments, vaccines are at the heart of the long-term fight to stop the new coronavirus, which has killed more than a million people, infected more than 38 million and crippled the global economy.
YouTube says it already removes content that disputes the existence or transmission of COVID-19, promotes medically unsubstantiated methods of treatment, discourages people from seeking medical care or explicitly disputes health authorities' guidance on self-isolation or social distancing.
In its blog post, YouTube said it had removed over 200,000 videos related to dangerous or misleading COVID-19 information since early February.
The company also said it was limiting the spread of COVID-19 related misinformation on the site, including certain borderline videos about COVID-19 vaccines. A spokesman declined to provide examples of such borderline content.
YouTube said it would be announcing more steps in the coming weeks to emphasize authoritative information about COVID-19 vaccines on the site.