Expanding capacity for vaccines against Covid-19 and future pandemics: a review of economic issues

We review economic arguments for using public policy to accelerate vaccine supply during a pandemic. Rapidly vaccinating a large share of the global population helps avoid economic, mortality, and social losses, which in the case of Covid-19 mounted into trillions of dollars. However, pharmaceutical firms are unlikely to have private incentives to invest in vaccine capacity at the socially optimal scale and speed. The socially optimal level of public spending may cause some sticker shock but-as epitomized by the tagline 'spending billions to save trillions'-is eclipsed by the benefits and can be restrained with the help of careful policy design and advance preparations. Capacity is so valuable during a pandemic that fractional dosing and other measures to stretch available capacity should be explored.

Optimal vaccine subsidies for endemic and epidemic diseases

Vaccines exert a positive externality, reducing spread of disease from the consumer to others, providing a rationale for subsidies. We study how optimal subsidies vary with disease characteristics by integrating a standard epidemiological model into a vaccine market with rational economic agents. In the steady-state equilibrium for an endemic disease, across market structures ranging from competition to monopoly, the marginal externality and optimal subsidy are non-monotonic in disease infectiousness, peaking for diseases that spread quickly but not so quickly as to drive all consumers to become vaccinated. Motivated by the Covid-19 pandemic, we adapt the analysis to study a vaccine campaign introduced at a point in time against an emerging epidemic. While the nonmonotonic pattern of the optimal subsidy persists, new findings emerge. Universal vaccination with a perfectly effective vaccine becomes a viable firm strategy: the marginal consumer is still willing to pay since those infected before vaccine rollout remain a source of transmission. We derive a simple condition under which vaccination exhibits increasing social returns, providing an argument for concentrating a capacity-constrained campaign in few regions. We discuss a variety of extensions and calibrations of the results to vaccines and other mitigation measures targeting existing diseases.

Designing advance market commitments for new vaccines

Advance market commitments (AMCs) provide a mechanism to stimulate investment by suppliers of products to low-income countries. In an AMC, donors commit to a fund from which a specified subsidy is paid per unit purchased by low-income countries until the fund is exhausted, strengthening suppliers' incentives to invest in research, development, and capacity. Last decade saw the launch of a $1.5 billion pilot AMC to distribute pneumococcal vaccine to the developing world;in the current pandemic, variations on AMCs are being used to fund Covid-19 vaccines. This paper undertakes the first formal analysis of AMCs. We construct a model in which an altruistic donor negotiates on behalf of a low-income country with a vaccine supplier after the supplier has sunk investments. We use this model to explain the logic of an AMC-as a solution to a hold-up problem-and to analyze alternative design features under various economic conditions (cost uncertainty, supplier competition). A key finding is that optimal AMC design differs markedly depending on where the product is in its development cycle.