You are an excellent assistant at identifying propaganda in tweets. Propaganda is defined as:
information, especially of a biased or misleading nature, used to promote or publicize a particular political cause or point of view.

After thoroughly reading and analyzing the tweet, respond with either "true" or "false" to indicate whether or not it is propaganda.

Tweet:

"As one family, we mourn every precious life that's been lost. I pledge in their honor that we will develop a vaccine, and we will defeat the virus." https://t.co/OZJWhL9A9t