Four key problems that will need to be addressed during the next pandemic

The four key problems

Problem 1. Misunderstanding about the terms ‘aerosol’ and ‘airborne’ transmission, and what procedures are ‘aerosol generating’

Traditionally, the terms ‘aerosol’ and ‘airborne’ were used to only refer to pathogens that can travel over long distances to cause infection. Yet, such aerosols can be produced by those infected and can transmit over much shorter conversational distances, simply by breathing and talking, traditionally referred to as ‘droplet’ transmission. This ambiguous term includes both smaller particles that can remain airborne, and larger particles that fall to the ground under gravity. Thus, aerosol transmission has always been a component of respiratory virus transmission and, therefore, no elaborate aerosol-generating procedures (AGPs) are required.¹

The phenomenon of AGPs arose because of the unusual characteristic of severe acute respiratory syndrome-coronavirus 1 (SARS-CoV-1), which mostly reached its peak viral load later during the infection, after patients had been admitted to hospital, when medical procedures, such as nebulisers, bronchoscopy and intubation, were required to maintain adequate respiration. This characteristic was unique to SARS-CoV-1, and did not apply to SARS-CoV-2 or the majority of other respiratory viruses, which are most infectious around the time symptoms develop, or immediately before.² The differences between SARS-CoV-1 and SARS-CoV-2 and the erroneous application of the term ‘AGP’ derived for SARS-CoV-1 to SARS-CoV-2, led to serious delays in recognising and accepting that SARS-CoV-2 behaved differently.

Problem 2. Some policy-makers, the media and some scientific experts were too ‘binary’ in their answers to the public in terms of questions about SARS-CoV-2 early during the pandemic

There were numerous disagreements between policy and scientific experts, in both the media and academic arenas, over many questions that had a direct public health impact; for example whether SARS-CoV-2 was aerosol transmitted,^3–5 whether masks worked,^6,7 whether children could become infected and transmit,⁸ and whether asymptomatic infection and transmission occurred, among others.^9,10

Early during the pandemic some politicians, policy makers and the media confidently declared one answer to these important scientific questions, even if such answers were supported by pilot data or mathematical models that had a large number of assumptions. Over the following 3 years, model parameters and assumptions were refined as more data regarding SARS-CoV-2 were collected. In some cases, this resulted in scientists eventually drawing conclusions opposite to what was initially thought.

These ‘paradigm shifts’ are crucial for the development of modern science as we know it. Normal scientific activity often progresses under a prevailing framework or model; paradigm shifts arise when the dominant model under which normal science operates is rendered incompatible with accumulating data, facilitating the adoption of a new theory or paradigm. There are numerous examples of such occurrences in human history (Table 1). However, during the COVID-19 pandemic, the certainty with which some leaders answered such statements relating to COVID-19 prematurely, only to backtrack or reverse those statements later, resulted in public mistrust and a much lower belief in science, when, in fact, this is a sign of scientific progress.

Problem 3. Public health guidance did not take into account that certain groups were less able to follow this guidance compared with other groups, even though the science behind it was robust

Physicians commonly encounter this situation in their daily practice. For example, patients might continue to eat fatty foods, even after their GP has advised them to stop because of their cardiovascular risk. However, in this situation, the main person suffering is the patient. With public health interventions and highly transmissible infectious diseases, the impact of not following the guidance might impact the wider community. This is why, during the COVID-19 pandemic, we also saw the rapid creation and passing of new laws to enforce public health infection control measures in the general population.

Unfortunately, enforced lockdown measures did not always take into account the fact that some family members had to physically leave their home to earn an income to support their families. This meant that the rules were broken, allowing the virus to spread further, although, generally, lockdown measures were still relatively effective in reducing the numbers of new COVID-19 cases over weeks to months. Furthermore, prolonged isolation can be harmful to certain groups, such as children, students and those living in care homes. For the next pandemic, there might need to be a limited amount of exposure allowed to preserve better the mental health of such groups. Trying to strike a balance between supporting the more vulnerable individuals while adequately maintaining greater protection for the larger community is always difficult, although some populations ran effective community lockdowns with daily support visits.¹¹

Problem 4. Worsening of existing inequalities

Individuals who were able to work from home in most countries were generally working in more highly paid professions and could financially tolerate national lockdown measures better that those working in the trade, hospitality, ‘gig’ or manual labour economies. These same individuals were more likely to be able to afford to send their children to private schools, which had better internet-based learning capabilities and, thus, their learning did not fall too far behind during school closures. These are only two examples of where the pandemic restrictions exacerbated differences between families in different economic strata, which required Government interventions to try to reduce these inequalities (eg furlough for workers, extra laptops for school children to learn from home, and some leniency in end-of-year school examinations).

Of particular note were the significantly poorer clinical outcomes in patients with COVID-19 from ethnic minority groups. This was initially thought to be related to genetics or biology (ie a higher risk of severe disease once infected). However, over the course of the pandemic, it became clear that this was more likely to be the result of the degree of social deprivation, which made these groups more likely to be exposed to infectious individuals, as well as of the general health of those from ethnic minority groups.^12,13

Such health inequalities also manifested more indirectly later during the pandemic, when COVID-19 vaccination became available, in terms of both vaccine supply and cultural elements. Despite the efforts of GAVI and COVAX, international collaborations to procure and distribute vaccines equitably among global populations that needed them, overseas ethnic minority populations often did not receive sufficient vaccines; even when available, these populations were much less keen to receive them compared with their White counterparts.¹⁴ This vaccine hesitancy in certain ethnic groups had the impact of allowing the virus to spread further in certain populations, particularly in those that had initially controlled the virus well with mass-masking and other non-pharmaceutical interventions (eg Vietnam, Thailand, Malaysia, South Korea, Japan and China). Even during the early COVID-19 vaccine trials, some countries found it harder to recruit volunteers from ethnic minorities to participate, resulting in vaccine licensing data that were poorly representative of these ethnic minority populations.¹⁵

Finally, there were inequalities of diagnostic assay reagent supplies to enable laboratories to test for the virus, with some preferred customers in some countries receiving their reagents first and in higher quantities than others. This raises the additional issue of supply-chain equality and how to deal with this equitably, when such reagents are generally supplied by private commercial companies. Is it more important to test a large conurbation populated with younger healthier working people than a small rural village community with older retirees?