Determinants of COVID-19 vaccine preference: A survey study in Japan

Abstract

Objective Vaccination is a critical measure for containing the COVID-19 pandemic. We survey the determinants that affect the preference for COVID-19 vaccines in Japan, a vaccine hesitant nation. Setting and design : We conducted a randomized conjoint analysis survey of the preference for vaccines on the Internet by recruiting a nonprobability sample of 15,000 Japanese adults. The survey assigned 5 choice tasks to the respondents. In each task, the respondents evaluated 2 hypothetical COVID-19 vaccines and were asked which they would choose. The vaccine attributes included efficacy, major and minor adverse side effects, country of vaccine development and clinical trial, and vaccine type. Treatment The choice task asked the participants to select a vaccine from 2 hypothetical vaccines as an optional vaccine or select a vaccine as a mandatory vaccine with a probability of 0.5 for each. Results Compared to vaccines developed in China, vaccines developed domestically or in the US raised the choice probability by 131% and 96%, respectively. A domestic clinical trial increased the choice probability by 33%. An increase in efficacy from 50% to 90% increased the choice probability by 43%. A decrease in the risk of severe side effects from 1 per 10 thousand to 1 per 1 million increased the choice probability by 38%. The vaccine type was irrelevant. Making vaccination compulsory increased the choice probability of China- and Russia-developed vaccines by 6% and 4%, respectively, and increased that of taking a high-risk vaccine by 5% and a modestly effective (70%) vaccine by 4%. General vaccination hesitancy, political positions, demographic characteristics, education, and income were irrelevant. Conclusions A domestically developed vaccine with a domestic clinical trial could substantially increase the preference for a vaccine. Making vaccination compulsory could modestly reduce the penalty for a vaccine with side effects, geopolitical, and efficacy concerns.

Public Opinion and Sentiment Before and at the Beginning of COVID-19 Vaccinations in Japan: Twitter Analysis

“…Our results showed that negative sentiment predominates positive sentiment in most time in Japan, when most previous studies of other countries exhibited more positive sentiment on social media [23,24,26]. The negative sentiment exhibited by our results consistent with the findings of some previous studies using surveys in Japan [40][41][42][43][44][45], and we provided fine-grained and more practical evidence. We observed a decrease in the correlation of negative sentiment with infection cases and death cases in Table 2, for which the direct reason is the decrease of infection and death cases and the abnormal increase of negative sentiment.…”

COVID-19 Vaccine Hesitancy among Italian University Students: A Cross-Sectional Survey during the First Months of the Vaccination Campaign

“…Lastly, freedom to choose which vaccine to receive, and its association with hesitancy, has been hypothesized by a few authors [47], but the issue is still under-investigated. In our study, the main drivers of choice were comparable to those found among Japanese people in February 2021 [48], except for the country of vaccine production, which we found replaced by vaccine type. This difference may relate to when the various surveys were conducted; unlike the Japanese respondents, our students were exposed to media reports in March and April 2021, alleging a worse performance for Vaxzevira (AstraZeneca AB, Södertälje, Sweden) [29], the most well-known viral-vector vaccine.…”

Trusting COVID-19 vaccines as individual and social goal

“…What is worst, enormous inequalities emerged in vaccine rollout, often mirroring limited access to vaccines due to financial constraints (e.g., in many countries in Africa 4 ), excessive caution in granting approval of foreign-produced drugs (e.g., in Japan 5 ), or supply problems (e.g., in Australia 4 ).…”