In this post, four members of Rethink Priorities’ invertebrates team—Daniela R. Waldhorn, Marcus A. Davis, Peter Hurford, and Jason Schukraft—outline their views on the value, feasibility, and danger of quantitative estimates of invertebrate sentience. Marcus and Peter provide numerical estimates of sentience for each of the taxa we investigated for our invertebrate sentience project, Daniela offers a qualitative ranking of the same taxa, and Jason argues that we are not yet in a position to deliver estimates that are actionable and robust enough to outweigh the (slight but non-negligible) harm that publishing such estimates prematurely might engender.

Animal Equality and Faunalytics put together a field study testing individual video outreach on belief and diet change. They found statistically significant results on both. Together with a Reducetarian Foundation study, we now think there is sufficient evidence to establish that individual outreach may work to produce positive change for nonhuman animals. However, evidence in this study points to an estimate of $310 per pig year saved (90% interval: $46 to $1100), which is worse than human-focused interventions even from a species neutral perspective. More analysis would be needed to see how individual outreach compares to other interventions in animal advocacy or in other cause areas.

We investigated the cost-effectiveness of vaccine research and development to learn about how cost-effectiveness estimates are made and where they might go wrong. By doing this, we became far more wary of taking these estimates literally. Many people will do things like reducing their cost-effectiveness estimate by a factor of 10x and call this a conservative estimate, but in light of this exercise and other examples, this is not enough. Furthermore, our research underscored that donating to the Against Malaria Foundation (AMF) may be a really hard baseline to beat and that it is important to do some degree of investigation before assuming things beat AMF. Lastly, our research has some implications for biosecurity that merit further exploration.

We looked at academic literature for vaccine cost-effectiveness as a whole and we also performed individual case studies on seven contemporary and historical vaccines to try to estimate the total cost-effectiveness of researching and developing a vaccine from scratch. Looking back historically, we find a range of $0.50 to $1600 per DALY, depending on the vaccine. Using this historical information, we derive an estimate for the total cost-effectiveness of developing and rolling out a “typical” / ”average” vaccine as being $18 - $7000 / DALY. The smallpox vaccine, malaria vaccine, and rotavirus vaccine may all be more cost-effective investments in total than marginal investments in distributing bednets, especially when pursued to the point of completely eradicating the disease. However, there are many important assumptions made by these models, and changing them could strengthen or undermine these conclusions.

Previously we estimated how expensive it is to research and develop a vaccine and also how expensive it is to roll-out a vaccine. If vaccines are to be cost-effective, we need to realize significant benefits in return for this expenditure. We take a closer look at the specific and tangible benefits that vaccines have shown to provide, both for our health and the economy.

We previously estimated the cost of developing a vaccine from scratch to be $460M to $1.9B with a mean of $960M. However, this still does not tell us the full cost of a vaccine, because developing a vaccine but then not ever using it accomplishes nothing. Instead, you need to roll out the vaccine to people, which costs more money. Thus, vaccine R&D could be thought of as “unlocking” the opportunity to roll-out a vaccine, and the hope is that the high cost-effectiveness of rolling out a vaccine will help offset the high cost of vaccine R&D. In this essay we evaluate the costs of rolling out a vaccine.

Previously, we estimated how long it takes to research and develop a vaccine and came up with a conclusion that it would take “an average of 29 years [to develop a] typical vaccine, though with high uncertainty based on uncertainties in each approach and on many particular vaccines not being typical”. However, if we want to know the cost-effectiveness of vaccine research, it’s not enough to know how long a vaccine takes, but how much total money it would cost. We attempt to estimate typical research and development costs for new vaccines.

Interventions related to vaccines seem to be highly cost-effective. The World Health Organization calls vaccines “one of the most powerful and cost-effective of all health interventions,” and the Copenhagen Consensus says that "[v]accination may be the most effective public health intervention of all time.”

We review historical evidence on timelines for developing new vaccines, and the cost-effectiveness of developing vaccines.