Vaccines under attack

Immunisation with life-saving vaccines is one of the greatest achievements in public health, but a growing wave of misinformation/disinformation in the wake of the COVID-19 pandemic threatens to undermine the many successes of vaccination.

The World Health Organization (WHO) estimates that the use of vaccines prevents 4 to 5 million deaths annually, and with better global vaccination coverage, this number could increase significantly.

The historical successes of vaccination campaigns are best known for the eradication and/or control of (now forgotten) deadly infectious diseases such as smallpox, which claimed millions of lives and was eradicated in 1980 through a concerted global vaccination campaign. Poliomyelitis too has been almost eradicated globally with cases markedly reduced since 1988 due to the efforts of many organisations, including the WHO, Rotary International, the Global Polio Eradication Initiative, and the Bill & Melinda Gates Foundation.

The reduction of deaths from measles through vaccination is also dramatic. Prior to widespread vaccination in 1963, measles was responsible for 2.6 million deaths globally each year, reduced by vaccination to 800 062 in 2000, and in 2022, there were 107 500 deaths — mostly in children under the age of 5 years, despite the availability of a safe and cost-effective vaccine.

Outbreaks of vaccine-preventable diseases can have devastating economic consequences and it should be emphasised that vaccines not only save lives but also significantly contribute to economic stability by reducing health care costs, increasing productivity, and minimising the burden on health systems.

For example, it has been estimated that for every US$1 invested in childhood vaccination in low and middle income countries, the return on investment is between US$16 and US$44 when considering broader societal benefits including economic productivity and long term health care savings.

Vaccination saves lives, and beyond the historical successes of smallpox, measles, polio and broader childhood and adult vaccination programs as outlined in the national immunisation program (NIP), vaccinations continue to offer significant protection against severe diseases.

COVID-19 vaccines and rising mis/disinformation

The rapid development of coronavirus disease 2019 (COVID-19) vaccines using mRNA, viral vector and/or recombinant protein platforms, demonstrated the power of bioinformatics and industry technology and expertise, together with streamlined regulatory processes, to speedily produce, test and register vaccines, preventing tens of millions of hospitalisations and deaths worldwide.

Without these vaccines, the COVID-19 pandemic could have led to an even greater loss of life, especially in the high risk groups, and further economic disruption. Unfortunately, growing mis/disinformation resulted in a decline in overall immunisation rates, placing millions of children at risk of vaccine preventable diseases.

During the COVID-19 pandemic, myths about mRNA vaccines altering DNA, causing infertility, or containing microchips gained traction online, despite overwhelming scientific evidence proving their safety and efficacy. The economic impact of the COVID-19 pandemic, exacerbated by vaccine hesitancy and mis/dis information on social media outlets, has been in the range of trillions of dollars.

This spread of vaccine misinformation and disinformation is possibly the greatest threat to vaccination efforts of our time. The rise of social media has amplified the spread of such information at an unprecedented scale. Anti-vaccine movements often leverage online platforms to disseminate pseudoscientific claims, conspiracy theories and misleading statistics, leading to fear and doubts resulting in vaccine refusal and outbreaks of vaccine preventable diseases.

Measles and under-vaccination

Recently, we have seen surges in measles cases due to under-vaccination. In 2024, there were 285 cases of measles in the USA and 89% of these cases were unvaccinated; 40% were hospitalised with 52% of hospitalisations among those under 5 years of age. A further surge occurred in 2025 (data to 6 March) involving 378 cases, with 95% of these cases unvaccinated; 17% were hospitalised and there were 2 deaths. Moreover, Europe has reported its highest number of cases in 25 years. From 1 February 2024 to 31 January 2025, 32 265 cases of measles were reported: 45.1% were in children under 5 years with the highest notification rates in infants, and 86.5 % were unvaccinated. In addition, measles is causing significant outbreaks in central Asia where cases have doubled.

Although vaccination rates remain high in Australia, they have decreased since the COVID-19 pandemic. Vaccination coverage for measles, mumps and rubella (MMR) remains below the WHO target rate of 95%, posing the risk of outbreaks. In addition, recent reports from the Grattan Institute show that vaccination rates for MMR have dropped below 90% in some areas including Adelaide, Fremantle, Noosa, Bankstown, with Queensland being the most affected state. There are also several communities in Western Australia where some 10% of infants are not fully vaccinated, thus increasing the risk of outbreaks throughout Australia as vaccination rates fall.

Measles is a serious disease that can cause significant complications, including blindness, ear infections, encephalitis, gastroenteritis, and respiratory issues including pneumonia. Measles during pregnancy can adversely affect the mother and result in complications for the newborn. Although a rare complication, a persistent measles infection can cause subacute sclerosing panencephalitis (SSPE), that typically presents in early adolescence and has a progressive course with a high mortality rate. Globally there are 4 to 11 cases of SSPE per 100 000 measles cases. SSPE can be prevented through vaccination.

Health care workers must be role models

Health care workers, especially doctors, nurses and pharmacists, play a critical role in administering vaccines and countering vaccine hesitancy. They are often the most trusted sources of medical information for patients, are important role models, and their participation in supporting vaccine uptake is critical. Vaccine hesitancy among health care workers will negatively impact public confidence. Studies have shown that when health care providers express doubts about vaccines, patients are less likely to get vaccinated. Conversely, the uptake of influenza and COVID-19 vaccines among health care workers was shown to improve vaccination rates in the general population. Addressing vaccine hesitancy within the medical community by emphasising the whole of life vaccination approach through continuous education and training is crucial to maintaining high immunisation rates in the community.

Politicians and public figures are also influential and results from a recent study suggested that a political speaker’s endorsement of the COVID-19 vaccine might increase vaccine uptake with those who identify with that speaker. Conversely, an expert’s factually accurate message may not increase voting intentions.

The juxtaposition of a self-declared “antivaxxer” overseeing vaccine programs in the USA and the plans to reinvestigate any link between vaccine use and autism, which has been firmly discredited, as well as the USA’s withdrawal of funding from the WHO, will likely further undermine the public’s confidence in vaccines. The recent announcements by the USA to withdraw funding for vaccines for poorer countries, and also from US state health departments, increases the risk of outbreaks of childhood infectious diseases, as well as tuberculosis (TB) and malaria in developing countries. According to the WHO, TB is re-emerging as the world’s leading cause of death from a single infectious agent with drug-resistant strains becoming a potential public health security threat.

We need to challenge and change the social media narrative through active steps to combat vaccine disinformation, which might include stronger regulation of misinformation online; proactive communication efforts to counter misinformation with easily understandable, evidence-based information (eg, the WHO Vaccine Safety Net); community engagement to help reach vaccine-hesitant populations and build trust in immunisation programs; and, fact-checking and science literacy to emphasise critical thinking in schools and the community at large, which may help individuals discern credible sources from misleading ones. Without strong immunisation programs, the world risks reversing decades of progress in disease prevention, endangering millions of lives and economies.

The COVID-19 pandemic is not over

Protection of high risk groups, such as immunocompromised patients and the elderly, through the use of booster vaccines is still critical to minimise COVID-19 cases and deaths; however, hundreds of Australians are still dying from COVID-19, especially at-risk vulnerable elderly people in aged care facilities. In the three month periods leading up to July 2023 and July 2024, there were very similar numbers of deaths in aged care facilities from COVID-19: the total for 3 May to 26 July 2024 was 442 deaths, compared to the similar period, 5 May to 27 July 2023, with 439 deaths indicating that vaccine boosters were not being administered. The elderly should be aware and also receive appropriate vaccinations for influenza virus, pneumococcal disease, shingles and pertussis.

Pandemic X

Another pandemic will come. Novel infectious disease threats have continued to emerge, such as mpox, which was twice declared a public health emergency of international concern by WHO. There is currently a pandemic of bird flu viruses affecting a variety of animals, including dairy cows (H5N1) in the USA and hens (H7 viruses) (some in Australia), and there are various arboviruses potentially emerging as pandemic candidates.

We cannot know what will cause the next pandemic but we can prepare by ensuring we have strong surveillance and laboratory systems, continuous monitoring of the animal–human interface, the sharing of viral genomes on databases, investment and support for industry to develop diagnostic kits as well as vaccines and antivirals, strong community and health care worker education programs, ensuring high rates of vaccinations against the diseases listed in the NIP, and the reliance on evidence through reliable scientific organisations rather than speculation and fear from social media outlets.

Professor Gary Grohmann is a consultant virologist and adjunct professor at the University of Sydney.

Acknowledgements: Gratitude to Dr John McEwen and Professor Robert Booy for reviewing the manuscript.

The statements or opinions expressed in this article reflect the views of the authors and do not necessarily represent the official policy of the AMA, the MJA or InSight+ unless so stated. 

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