Can’t solve pandemics – vaccine hesitancy prevents herd immunity.

Vaccine hesitancy—the reluctance or refusal to vaccinate despite the availability of vaccines- is rising worldwide. Even though vaccines are considered one of the most important achievements of public health, preventing an estimated 2.5 million deaths each year worldwide and reducing disease-specific treatment costs [1], the World Health Organization (WHO) identified vaccine hesitancy as one of the top ten global health threats of 2019 [2].

Vaccine hesitancy is not a new trend. Since 1795, when Edward Jenner published the book titled “An Inquiry into the Cowpox”, vaccination has become a mainstream medical practice all over the world [3]. Nevertheless, from their beginnings, inoculations have had their detractors. The earliest ones were men of the church. They reasoned that infectious diseases were a God-given fact of life and death. Some medical doctors, those that were earning a lot of money from useless but lucrative cures, also enrolled in the anti-vaccination movement early [3]. Vaccination was associated with diverse hazards including tuberculosis, cancer, madness, blood poisoning, and syphilis [4]. From the middle of the 19th century, Great Britain and the countries under its influence made vaccination compulsory. Parents that refused to inoculate their children were sent to prison. The results were disastrous, with social riots that ended with the abolishment of the acts that made vaccination compulsory in 1909. The lessons provided by these first experiences were clear: the risks of vaccination must not be silenced, and compulsory vaccination was not the answer to the lack of public confidence in vaccines.

Nowadays, vaccine doubters are increasing in number. In several Western countries, diseases that had nearly been eradicated are coming into sight again due to their vaccine rates weakening. Vaccine refusal has been increasing in many EU member states [5]. Between 2000 and 2019, the uptake of measles-containing-vaccine first-dose has decreased in 12 EU member states [6]. Moreover, 14 EU member states were below the immunization rate threshold of 95% that was required to achieve herd immunity in 2019 [7]. The same situation could be found in seasonal influenza and other infectious diseases [5]. The last episode of vaccine hesitancy is related to the COVID-19 pandemic. Some people are afraid that the pace of both scientific review and vaccine control could compromise safety. Differences in acceptance rates rage enormously from country to country around the world [8,9]. Governments, public health officials, pharmacy companies, and other stakeholders are worried about people’s willingness to receive vaccines when appropriate [10].