duckduckgo doesn't manage %100 of their search results - meaning that when you search there you are going to get a mixed bag of results and most of those results are not coming from the search index DuckDuckGo maintains.

DuckDuckGo uses its web crawler, DuckDuckBot, and up to 400 other sources to compile its search results, including other search engines like Bing, Yahoo, and Yandex, and crowdsourcing sites like Wikipedia.

Depending on what you are looking for I suggest looking around various search engines to see what you get.

startpage.com

ecosia.org

I also suggest refining your search. You can explicitly tell the search engine to shut up and give you results no matter what.

+"vaccinated person hospitalized"