In a push for more Americans to be vaccinated, Sen. Bernie Sanders reminded of a well-known meme.Sanders tweeted Monday, "I am once more asking you to get immunized."This line was taken from a campaign ad for Sanders that went viral in 2019. Sanders requested donations from supporters.10 Things in Politics: Keep up to date with the most recent political and economic news. Loading Something is loading. Click Sign up to receive marketing emails and other offers from Insider.Sen. Bernie Sanders resurrected an iconic meme from his presidential campaign in 2019 to encourage Americans to get vaccinated for COVID-19.Although the senator from Vermont may not have been elected president, it was able to win the Internet. A screenshot of a campaign advertisement that Sanders posted in December 2019 went viral. It asked for donations from supporters to meet the Federal Election Commission fundraising deadline.Sanders stated in the video, "As 2019's FEC fundraising deadline approaches, I am again asking for your financial assistance."According to Know Your Meme (an unofficial database that tracks internet phenomena), the latter half of this line gained popularity in 2020. "Memes imagining different scenarios in which monetary contributions are being requested" according to Know Your Meme.Sanders tweeted Monday the famous line: "I am again asking you to get vaccinated."This tweet comes as the Delta variant surges across the US, as a plateau in vaccination rates slowly ticks upward. According to data from Centers for Disease Control and Prevention, 70% of adults in the United States had received at least one dose (COVID-19) vaccine by Monday.Apart from urging Americans get the shot, Senator has repeatedly called on US pharmaceutical companies (including Pfizer, Moderna and Johnson & Johnson) to surrender intellectual property rights to COVID-19 vaccinations. This would allow global production of vaccines.Sanders stated that "we have to obviously ensure that every American gets vaccinated in the quickest possible" during a May appearance on "Meet the Press" on NBC News. We have a moral obligation to help the rest, but it is also in our self-interest. This pandemic will come back to bite us if it continues spreading in other countries.Since then, pharmaceutical companies have opposed the calls and the World Trade Organization has failed to agree to a proposal to issue temporary waivers on IP rights.According to Reuters, Sanders was one of nine senator Democrats who urged President Joe Biden in April to temporarily waive IP rights to vaccines to allow vaccines to be made locally by other manufacturers. Later, the Biden administration announced that it supported the temporary waiver. They stated that "extraordinary circumstances" require "extraordinary measures".