For many, the instinct in times of uncertainty is to reduce costs, including advertising spend. Research shows that there are benefits to increasing or maintaining ad spend during times of crisis. Here's a roundup:

In this report on advertising in a downturn by IPA via thinkTV, research suggests that reducing your Share of Voice in the market can have detrimental long-term effects. The research states that the long term improvement in profitability outweighs the short term cost reductions and ultimately brands that didn't cut advertising costs emerged more successful in the long run.  

This article from Media in Canada talks about how brands are re-evaluating their messaging. It's an opportunity to pivot during a time of significantly increased media consumption. Likewise, consumers are shifting their expectations of brands. In a study from Kantar, over 77% of respondents said they are looking for brands to take a more authentic and comforting approach, and only 8% think companies should stop advertising during this time.