Hviid et al. 2019 Vaccine-Autism Study: Much Ado About Nothing?

The controversy surrounding measles, mumps, and rubella (MMR) vaccination and autism has been ongoing for over 30 years. It is rooted in the parent-led grassroots movements of the 1990s; and a case-series clinical study in 1998 by Wakefield et al. This controversy cascaded through numerous observational studies and US Institute of Medicine reports, culminating in 2019 with a population-based observational study by Hviid et al. This study was hailed at the time by the US media and medical establishment as conclusive proof that the MMR vaccine does not increase the risk of autism, even among “genetically susceptible children”. However, as detailed in this critical review, Hviid et al. did not faithfully intend or interpret the data to test this hypothesis and, therefore, cannot possibly have falsified it. We elucidate methodological flaws, discrepancies, irreproducibility, and conflicts of interest for Hviid et al. In addition, the conclusion from Hviid et al. cannot be generalized to the CDC childhood vaccination schedule. All these salient features have remained oblivious to so many regulators, mainstream media, and professional associations in the USA. This reveals the need for more communication about the limitations of available evidence to facilitate informed consent for the childhood vaccination schedule.