How flawed ‘droplet spread’ narratives shaped the UK's COVID policy response

In a recent analysis published in the British Medical Journal, Trisha Greenhalgh and colleagues explored inaccurate narratives of the mode of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, propagating that it spreads through droplets and fomites but not air. The authors examined four complementary hypotheses to explain why these flawed narratives prevailed in the United Kingdom (UK) for so long.

Analysis: How covid-19 spreads: narratives, counter narratives, and social dramas. Image Credit: Tomas Vynikal / Shutterstock

Psychological

In the face of complex and contradictory evidence, people are unlikely to change their beliefs due to the effort required and the likelihood of aversion. As a result, policymakers narrowed the parameters within which they could make decisions while still appearing accountable due to the complexity and urgency of COVID-19’s threats.

Scientific elitism

Scientists value their favored methods and impose a narrow and rigid set of acceptable scientific methods that academic Kurt Danziger called “methodolatry.” They could not discard their long-held droplet-but-not-airborne narrative. Instead, they chose to ignore the science of indoor air quality and aerosols because they felt this part of science was in its infancy compared.

Logistical

Due to the national shortage of high-grade personal protective equipment (PPE), the UK policy advisory groups adhered to a droplet-but-not-airborne narrative and facilitated that existing stocks go further.

Political

Had they propagated SARS-CoV-2 as an airborne infection, the UK government would have needed a paradigm shift in policy making, with strategic actions from those responsible for public safety. Under the guise of empowering the public, they chose populism that appeals to public desires for normalcy and validates anti-science sentiment. It further marginalized aerosol science by depicting its recommended measures as obscure, unaffordable, and against the public interest. Furthermore, it saved the government from making an up-front investment in an environment that may not reap benefits for many years.

Not only could the UK contain widespread SARS-CoV-2 spread by relying on mitigation measures aimed at an assumed droplet pathogen (e.g., handwashing, social distancing), they under-emphasized measures to reduce airborne transmission. As a result, a narrow group of scientific advisers and their misguided policies led to uncalled-for deaths in care homes, high infection rates among health workers, and delayed public disclosure.

The researchers quoted contrasting early announcements regarding SARS-CoV-2 transmission in the UK and Japan. Japan’s government agreed that in the absence of enough scientific evidence, people should avoid crowded places, places with poor ventilation, and close proximity to conversations and vocalizations.

Contrastingly, public health policymakers from England assumed the droplet mode of SARS-CoV-2 transmission with high certainty. Hence, they recommended washing hands often, using sanitizers, and following all general principles to prevent respiratory viruses from spreading.

Furthermore, the UK policymakers assumed the superiority of randomized trials, which typically serve clinical medicine but not always public policy. Aerosol scientists have shown that SARS-CoV-2 is transmitted through the air using laboratory studies, real-world case studies, and computer modeling. Nearly ten streams of evidence support the airborne transmission of SARS-CoV-2.

For example, nosocomial infections occurred despite strict distancing, and droplet precautions worked well only with airborne precautions. Another remarkable example is the phenomenon of long-range transmission, where SARS-CoV-2 infected people who never physically met or touched any common surface. In studies, SARS-CoV-2 was found to be viable in building ducts, and the virus was transmitted from animal to animal through air ducts when cages were connected.

Eventually, the UK policymakers rejected or dismissed a wealth of evidence on the science of optimizing indoor air quality. Instead, they ritualized droplet precautions. These measures became ubiquitous, people washed hands for 20 seconds, quarantined and disinfected their homes, and stayed 2m apart, and institutions also policed the various artifacts and practices. “Clean” and “contaminated” came to be demarcated in terms of droplet precautions and not air purity, which further downplayed or obscured the narrative of SARS-CoV-2’s aerosol transmission.

The UK reported 18,104 COVID-19-related deaths above the five-year UK average among care home residents between March and June 2020. Furthermore, Public Health England’s guidance for care homes did not stress the importance of ventilation, mask use, or personal protective equipment, which most likely amplified transmission between infected residents and care home staff. Conversely, in Hong Kong, all care home staff mandatorily used masks by late January 2020, preventing excess care home deaths during the first wave of COVID-19  between March and June 2020.

The UK’s public health officials ignored that since everyone generates aerosols, everyone is therefore prone to contracting COVID-19. A review of the aerodynamics of respiratory acts showed that a critical triad of poor ventilation, crowding, and loud vocalization generates enough aerosol for superspreading events. Indeed, these findings raised questions, such as whether more attention should be paid to measures, such as ventilation or filtration of air, or ensuring that fewer people share air for shorter periods.

Conclusions

The COVID-19 pandemic affected all domains and layers of society, economic, legal, political, and religious. Cognitive biases and satisficing behavior of policymakers, the tendency to favor some scientists and reject outside-track scientific voices, and politicians’ alignment with populist sentiments proved precarious. Though COVID-19 continues to claim lives and cause long-term illness more than two years after its emergence, the mitigations needed to manage its airborne transmission remain under-recognized. The inside track for pandemic policy making in the UK and via the World Health Organization was narrow, partisan, and extraordinarily, never mentioned masks or ventilation.

The authors proposed ten specific questions about the UK policymakers’ accountability concerning past and ongoing omissions in the COVID-19 context. By doing so, the science of SARS-CoV-2 transmission would be free of historical mistakes, vested interests, ideological manipulation, and policy satisficing. Furthermore, it would increase inclusivity and support for interdisciplinarity and pluralism routes, thus reducing the massive inequalities caused by COVID-19.

How covid-19 spreads: narratives, counter narratives, and social dramas, Trisha Greenhalgh, Mustafa Ozbilgin, David Tomlinson, consultant cardiologist and electrophysiologist, BMJ 2022, DOI: https://doi.org/10.1136/bmj-2022-069940, https://www.bmj.com/content/378/bmj-2022-069940