Evaluation of the Impact of Shandong Illegal Vaccine Sales Incident on Immunizations in China

"...public trust in vaccination is not always based on scientific evidence but often results from many factors related to psychology, social science, and politics..."

On March 18 2016, the news site thepaper.cn reported a case of illegal vaccine sales uncovered by the police in East China's Shandong province. The incident triggered widespread public concerns over vaccination safety and provoked a public health crisis in China. This study aimed to evaluate the impact of the incident on immunisations, to investigate the variation of the immunisation coverage of the National Immunization Program Vaccines (NIPV) and the sales volume growth rate of Category II vaccines, and to understand the reasons for non-vaccination and perspectives on immunisation.

In China, vaccines are divided into 2 categories: Category I vaccines are those that are provided free of charge by the government to the citizens, mainly including the NIPV; Category II vaccines are the vaccines that need to be self-funded. In contrast to Category I vaccines, which are distributed with stringent cold-chain management by the Centers for Diseases Control and Prevention (CDC), the procurement and distribution of Category II vaccines are usually undertaken by enterprises. The incident that started at Shandong province involved only Category II vaccines, which were apparently stored and transported without the proper care to obtain higher profits. On April 13 2016, it was confirmed that the illegal vaccines had been disposed of, more than 200 people had been detained for their involvement in the incident, and 357 government employees had received punishments.

The researchers conducted a study comprising 2 cross-sectional surveys: at 2 months (May 2016) and 7 months (October 2016) after the incident. Although NIPV were not involved in the incident, the immunisation coverage of NIPV decreased by 5.6 percentage points in the first survey, with a decline of 11.1 in the region of the incident, and it decreased by 0.6 in the second survey compared to same period in 2015. The sales volume growth rate of Category II vaccines decreased by 25.8% in the study area and by 48.8% in the region of the incident in April 2016 compared to April 2015.

In addition, the researchers interviewed 2,255 and 2,189 guardians of children in the first and second surveys, respectively, who did not receive the NIPV vaccination according to the vaccination schedule after the incident. A total of 86.8% of the respondents said they had heard of the incident. The main information source regarding the incident was the internet, accounting for 49.6% of the respondents. Overall, 15.8% of respondents in the first survey and 7.0% in the second survey did not vaccinate their children according to the NIPV schedule because of the incident. Although the proportion of parents who were hesitant about their children receiving vaccinations decreased from 22.3% to 8.6% in the second survey, 34% of respondents still avoided Category II vaccines for their children, indicating that it will take considerable time to eliminate the negative stigma associated with the incident.

That said, after the government took the necessary steps to contain the incident and carried out positive publicity and health education, the immunisation coverage of NIPV in September 2016 only decreased by an average of 0.6% compared with that in September 2015. This indicated that the negative influence on NIPV vaccination might be weakening or may have even gradually disappeared. In addition, the use of Category II vaccines gradually improved by 10% to 15% between August and September 2016, which seems to indicate that the concerns raised by the incident had eased.

This study showed that there was a substantial impact on vaccination, as vaccinations decreased after the incident; however, the public seemed to remain observant and did not rush to make a decision while the situation was unclear. Thus, a prompt communication response to the incident might be helpful to mitigate the negative impact in such situations.