Why Freeriding is Bad for COVID-19

--- title: Why Freeriding is Bad for COVID-19 tags: live-v0.1, behaviour, policy permalink: https://c19vax.scibeh.org/pages/freeriding ---  {%hackmd 5iAEFZ5HRMGXP0SGHjFm-g %} {%hackmd GHtBRFZdTV-X1g8ex-NMQg %} # Why freeriding might be a disastrous strategy ## Individual protection and group benefits Vaccines protect against infection by activating the body's natural immunity. Vaccinations therefore offer direct benefits to the individual who receives the vaccine. However, vaccinations also protect others around the person being vaccinated by reducing the spread of the disease. When enough people are vaccinated against diseases that can be spread from person to person, this creates ["herd immunity"](https://www.immunology.org/celebrate-vaccines/public-engagement/guide-childhood-vaccinations/how-vaccines-work), which means that even those people who cannot get a vaccine (e.g., because they are too young or have a health condition) are protected because the disease cannot spread when nearly everybody in a population is vaccinated. **Vaccinations therefore play a dual role: they protect the person being vaccinated, but they also offer protection to others in society, even people we don't know.** ## Opportunities for altruism and freeriding The dual role of vaccinations opens up an avenue for altruism ([Brewer et al., 2017](https://journals.sagepub.com/doi/10.1177/1529100618760521)): We may decide to get vaccinated to protect other, weaker members of society. Indeed, when people are reminded of the prosocial consequences of vaccinations, they often become more willing to get vaccinated ([Betsch et al., 2017](https://dx.doi.org/10.1038/s41562-017-0056)). However, the dual role of vaccinations also creates an opportunity for the opposite response: Some people may decide to become "freeriders" and let others get the vaccine while they get the beneficial effect of herd immunity without being vaccinated. Vaccination decisions thus pose a social dilemma in which the choice to be vaccinated increases the public good by conferring herd immunity, and the choice not to be vaccinated represents freeriding on others’ prosocial actions while also putting oneself and others in danger. Freeriding is often considered unfair and morally unjustified ([van den Hoven, 2012](https://dx.doi.org/10.1093/phe/phs023)). It is therefore unsurprising that vaccinated individuals show less generosity toward nonvaccinated individuals in experiments because they are seen to be in violation of a social contract ([Korn et al., 2020](https://dx.doi.org/10.1073/pnas.1919666117)). However, the situation with coronavirus is special and it is crucial to explain why freeriding should be avoided even more than normal. ## The implications of freeriding There are serious reasons why freeriding in relation to the COVID-19 vaccine might be disastrous, both for the freeriders themselves and for the people around them: * **Individual safety**: We cannot be certain that someone is not in danger of getting sick from COVID-19. By remaining unvaccinated, even if you do not belong to a high-risk group, [you increase the possibility of contracting coronavirus](https://hackmd.io/8Z8HRpVlTomKMWV9ZDK1qw), getting sick and spreading it to others. Furthermore, belonging to a low-risk group does not necessarily mean that one is safe from severe illness. In fact, COVID-19 has been shown to cause serious neurological problems ([Ellul et. al. 2020](https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3589350)) and long-lasting adverse effects ([Yelin et al., 2020](https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30701-5/fulltext)), and it does not spare any group, even young people without comorbidities. At the same time, side-effects from the vaccine have so far been relatively [mild and scarce](https://www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination/coronavirus-vaccine/). This means that the individual risks one could expect in relation to the COVID-19 vaccine are rather insignificant compared to the risk of getting sick from the virus. * **Herd immunity**: Even if freeriding was an effective individual strategy (which is not, as explained above), if it becomes a norm, the necessary percentage of the vaccinated population needed to reach herd immunity will not be reached (or will be reached much later) and everyone will continue to be at risk ([Brewer et al., 2017](https://journals.sagepub.com/doi/10.1177/1529100618760521)). In the case of COVID-19, freeriding is particularly problematic for two reasons. First, because the vaccines and the disease are novel, we must start immunizing from scratch. Second, because it is unknown how long the vaccines will offer protection, the level of immunization required in the first year may be particularly high. When a vaccine can be assumed to provide life-long protection, the level of immunization that is required to achieve herd immunity is a function of the "reproductive number" (_R_$_0$). The reproductive number represents the number of people that an infected person will in turn infect on average. For COVID-19, where estimates for _R_$_0$ (without lockdown) are in the range of 2.5 -- 3.5, then a "perfect" vaccine (100% effective) will achieve herd immunity if between 60 -- 72% of people are immunized. If a vaccine is 80% effective, then herd immunity will require immunization levels of 75 -- 90% for the values of _R_$_0$ that have been cited for COVID-19 ([Anderson et al., 2020](https://dx.doi.org/10.1016/s0140-6736(20)32318-7)). Now suppose the duration of protection provided by the vaccine is only a few years, rather than life-long. The figure below, taken from Anderson et al., shows the implications for the first year after vaccine rollout (panel A) and for subsequent years once vaccination has been ongoing for 2-3 years. ![](https://i.imgur.com/9EDeXal.png) It is clear from panel A that even a highly effective vaccine (say around 90%) requires that around 90% of the population are vaccinated in the first year to achieve herd immunity _if the protection it offers is limited to one year_. * **Sensitive groups**: Specific groups of people may not be able to get vaccinated, at least until we have more data about potential side-effects (individuals with a history of [severe alergic reactions to other vaccines or to components of the COVID-19 vaccines](https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/allergic-reaction.html), [children aged below 16 for Pfizer's and 18 for Moderna's & Oxford-AstraZeneca's vaccines](https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html), and [pregnant/breastfeeding women](https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/pregnancy.html)), while seriously immunosuppressed patients may be in [risk of reduced vaccine efficiency](https://www.ajmc.com/view/covid-19-vaccine-considerations-for-the-immunocompromised). This means that, for all of these people, the only hope for safely returning to a normal life without the constant fear of getting sick with COVID-19 is through herd immunity. If freeriding becomes a norm among the people who are able to get vaccinated, then these sensitive groups are condemned to exclusion and constant risk of getting sick.  ## Conclusion Evidence suggest that the protection offered by COVID-19 vaccines last at least six months ([Hall et al., 2022](https://www.nejm.org/doi/10.1056/NEJMoa2118691)). Hence, individuals who received two shots are less likely to contract the virus and risk hospitalization or admission to an intensive care unit (ICU). Given the resource intensive treatment of COVID-19 patients and the limited availability of ICU beds, although not offering herd immunity, the vaccine still helps to conserve resources in the heavily-strained healthcare system. These facts highlight the **small individual benefits** that one can expect from freeriding and the **extreme possible individual and social risks** it can cause. Thus, it is important to communicate them widely in order to decrease willingness to freeride and efficient vaccination ([Betsch, Böhm, & Korn, 2013](https://psycnet.apa.org/record/2013-30843-007)). :::success Would you like to find out more about why freeriding might be a disastrous strategy for managing COVID-19? We created a search query specifically for this page, which links you to other interesting resources like Twitter threads, blogposts, websites, videos and more. Check out the search query that we generated specifically for this page [here]( https://hypothes.is/groups/Jk8bYJdN/behsci?q=individual+benefits). Would you like to know more about how we generated the search queries and how our underlying knowledge base works? 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