From halting medical research funding and withdrawing from the World Health Organisation (WHO) to appointing a vaccine sceptic as health secretary, America has gone through some major recent changes in its approach to public health.
Vaccine hesitancy is not a recent development or side effect of these actions, but it has certainly become more widespread. Nowadays, it is increasingly difficult to discern what is real and what is fake online, especially with the widespread dissemination of misinformation by artificial intelligence and conspiracy theorists.
Where does vaccine hesitancy come from?
Vaccine hesitancy can arise for many different reasons.
Something as simple as not having the time to get a vaccine, or in the case of the flu jab, not believing a booster or seasonal jabs are necessary, can be a fairly common reason that people avoid getting vaccinated.
An example of a more extremist belief that anti-vaccine activists, also known as ‘anti-vaxxers’, hold is that the ingredients used for vaccines are unnatural, and cause disease and illness in people rather than providing protection from viruses.
Mercury-based preservatives, such as thimerosal, were common ingredients used in vaccines, though exposure to elemental mercury is dangerous and harmful to the human body. As a compound in a vaccine, however, it is an effective preservative that prevents germ growth and contamination of the drug. Robert F. Kennedy Jr., the USA’s current health secretary, banned thimerosal in all US vaccines in July 2025, after firing and replacing all 17 members of the Centers for Disease Control and Prevention (CDC)’s advisory committee for immunisation practices.
The way vaccines are engineered and created can seem like a mystery to the general public, mainly because people do not know where to look for the knowledge, and due to misinformation and falsities on manufacturing techniques being spread. Lack of education is such an important factor in the rise of vaccine hesitancy, and if some of the myths and mysteries of vaccine development were dispelled, people would feel less scared about what was being put into their bodies.
Why are vaccination rates decreasing?
Amongst RFK’s many claims is the recent association of taking Tylenol (paracetamol) during pregnancy with resulting autism in the baby. This is a shift from the still present anti-vaxxer belief that autism is caused by vaccines, which has been a major driving factor in decreased vaccination rates across the USA and indeed throughout the western world, and has had far-reaching consequences.
The infamous 2019 Samoa measles outbreak has been tangentially linked to RFK’s influence in spreading anti-vaccine sentiments in the island. This crisis resulted in 83 deaths, many of which were children. In October 2025, the CDC declared a measles outbreak in South Carolina with 8 confirmed cases, all of which were unvaccinated individuals.
This follows a recent trend in the USA and the UK, with pockets of measles outbreaks occurring in areas with low measles vaccination uptake.
Measles in particular is a highly dangerous and infectious virus, with a reproduction number (R0) of 12-18, meaning that every infected person will go on to infect 12-18 others. To protect people from measles, over 95% of the population needs to be vaccinated to achieve herd immunity, and to protect those who are either immunocompromised or unable to receive the vaccine themselves.
The majority of adults have already had the MMR (measles, mumps, and rubella) vaccine, but that is not who this current wave of vaccine hesitancy will affect. Children are especially susceptible to infection, and measles poses a distinct danger to them in the form of subacute sclerosing panencephalitis (SSPE), which is a fatal brain disorder arising from measles infection complications.
These are worrying times for the protection of public health. The recent COVID pandemic has only highlighted how important vaccination is for protecting yourself and those around you from viral infection. The measles vaccination coverage has not yet recovered to pre-COVID levels in the UK, and with mounting mistrust and anti-vax sentiments, it will struggle to reach them anytime soon.
