First, we have no actual behavioral studies in this area—as opposed to the case of smoking cessation rewards. Similarly, as the proponents of vaccination rewards admit, there is no data on how to set the appropriate reward.
Second, the proposal might backfire. People who already do not trust vaccines may consider the mere availability of payment as confirmation that vaccination is especially risky or undesirable. And people or organizations interested in promoting disinformation about vaccines may portray payment originating from the government as “proof” of deep-state or hidden agendas associated with vaccination. If people perceive the monetary incentive in this way, that could contribute to increased vaccine hesitancy – precisely the opposite of what it is intended to do.
Third, we worry about the socioeconomic underpinnings of this proposal. An amount close to $1,000 is supposed to prompt a person to change attitudes toward vaccination. In practice, this means that richer individuals, who might not be moved by $1,000, can just ignore the reward. Poorer people, however, are expected to change their behaviors in exchange for money. This is a paternalistic approach that does not help build trust in the government and public health authorities among poorer communities.