Approaches to Combatting the COVID-19 Pandemic

Findings and Recommendations

There are infectious diseases that are both more or less contagious and more or less fatal than COVID-19. However, what makes COVID-19 so dangerous is that it is a newly emerged viral disease for which there was no existing immunity in humans. COVID-19 could rapidly infect the majority of the global population, much more than any other infectious disease. A worst-case scenario suggested that, without any countermeasures, 90% of the world population could have got infected (1).

Such development occurs quickly, with one infected person transmitting to others at an average speed of 4-8 days (1).

Further uncertainty and risk are posed by the fact that emerging diseases can have higher mutation rates, which can lead to more or less harmful strains. This is the case with variants that crowd out older strains, such as the variants Alpha to Omicron, which is thought to be possibly four times more contagious and to require an additional vaccination dose (1). The mutations even go so far that the recovered have little natural immunity from infection with an older strain of the virus and the effectiveness of vaccines decreases with each major variant (1).

COVID-19 kills by the millions. The pandemic caused 1.78-1.80 million confirmed deaths globally in 2020 (1). By the end of 2021, this number has grown to 5.41-5.45 million (2). By April 2022, it is projected to increase to 6.59 million, even with the current countermeasures and vaccination plans (3). Including unreported cases, the global death toll is estimated at 12.6 million by the end of 2021 and projected to rise to 13.9 million by April 2022 (4). Another estimate of total deaths - confirmed and unreported - includes as many as 18.6 million at the end of 2021 (5).

These figures include undiagnosed cases but not the aggravating impact of COVID-19 on other health issues. Anyway, the death toll per year surpasses by far that of any other infectious disease (including pneumonia/lower respiratory infections, tuberculosis, hepatitis, HIV/AIDS or malaria). The annual COVID-19 death toll is also higher than that of child and maternal undernourishment. It was similar to that from outdoor air pollution in 2020, which included the build-up of the pandemic, but much higher in 2021 (1). The impacts of COVID-19 exceed those of all other global problems covered by the Global2030 review, such as neonatal mortality or unsafe water (see the following diagram) (2).

However, deaths from COVID-19 could have been much higher if strong countermeasures had not been undertaken. Worst-case scenarios, assuming no mitigation measures, indicated a multiple death toll in the tens of millions, similar to the 1918/19 influenza pandemic death toll ("Spanish flu") (1). Therefore, it is appropriate that countries treat COVID-19 as the most immediate global challenge.

The human impact of COVID-19 can be reduced not only by lockdown and containment measures, but now also - at lower societal and economic costs - through the roll out of the largest vaccination programme in human history. However, the COVID-19 vaccination programmes face obstacles as they need to be expanded globally and will need to be repeated, to an extent currently unknown.

COVID-19 can transmit from person to person via

• respiratory droplets released through coughing, sneezing, laughing, shouting, singing or speaking (1)
• aerosols released in the same way and additionally through breathing out, or formed by droplets shrunk through evaporation, allowing for airborne transmission of COVID-19 up to several meters, or room scale (2), probably being infective for at least three hours (3) (4)
• and contact to lips, nose or eyes, e.g. by hands contaminated with the virus from a handshake or a surface contaminated by droplets or touch (5).

These transmission paths can be prevented by

• wearing face masks, which protect both the wearer and others against contaminated droplets and aerosols (1). There are different types of face masks available:
• N95, FFP2 or FFP3 masks/respirators have a 92.8-99.9% efficacy, if fitted correctly, otherwise efficacy is below 70% (2).
• surgical masks have a 75-94.5% efficacy, if fitted correctly, otherwise below 70% (3). -
  The Hong Kong general public had a face mask usage of 96.6%, and an 82.7-95.7% lower incidence rate of COVID-19 compared to major non-mask-wearing countries (4).
  Source: Chi-Chung et al. (April 2020), p. 111.
   
• cloth masks have different efficacies against the COVID-19 virus, from 25 to 89%, depending on the material used. If no nose clip is integrated, the efficacy is even lower, as a leakage of 1% roughly halves the filtration capacity (5).
• masks with a ventile only protect the wearer (6)
• wearing eye-protection or faceshields (7) or (large) glasses (8) could prevent viral transmission via the eye
• physical distancing, e.g. maintaining a distance of 1.5-2 metres or more (9); but this does not help in rooms filled with aerosols (10)
• good ventilation in closed rooms (11)
• cough hygiene by coughing into a tissue, elbow or non-reusable handkerchief (12)
• hand hygiene by avoiding handshakes, avoiding touching handles used by others, avoiding touching ones face and regularly washing hands thoroughly with soap or disinfection solution (13)
• applying disinfectants to contaminated surfaces (14)
• and last but not least, reducing the frequency and duration of direct contacts with other persons, particularly those not using the above-mentioned means of prevention (15).

Combining these preventive measures will be more effective in reducing the virus' transmission.

The measures are included in the prevention plans of many businesses and institutions as well as in governmental policies to address COVID-19.

At the beginning of the pandemic, in Western countries, there was some reluctance to be seen wearing or to recommend wearing face masks to individuals in a non-medical setting. Considerations to ensure adequate supplies for medical personnel conflicted with considerations to preventing transmissions by use of face masks by other people. "Perhaps it would also be rational to recommend that people in quarantine wear face masks if they need to leave home for any reason, to prevent potential asymptomatic or presymptomatic transmission. In addition, vulnerable populations, such as older adults and those with underlying medical conditions, should wear face masks if available." "As evidence suggests COVID-19 could be transmitted before symptom onset, community transmission might be reduced if everyone, including people who have been infected but are asymptomatic and contagious, wear face masks." (1) With widespread evidence encouraging the use of face masks, their usage was eventually recommended for the general population. An important reason for this follows from the fact that infected people become contagious before developing symptoms (2), and sometimes without developing any (3). This includes children, adolescents and adults (4). Thus, one does not know who can transmit the virus, including oneself.

Tuberculosis: The lockdown measures to reduce COVID-19 did have a positive impact in temporarily reducing tuberculosis transmission. However, that effect could easily get more than outweighed by a 3 months suspension in tuberculosis services, followed by a further 10 month periods to return services to normal, which would result in an additional 1.20 million cases of tuberculosis over the next 5 years. These negative impacts could be mitigated by rapid restoration of tuberculosis services and targeted interventions (1).

Malaria prevention: Whilst most malaria prevention services were able to progress during 2020, even a 25% disruption in access to effective antimalarial treatment in sub-Saharan Africa could lead to 46,000 additional deaths (1).

Treatment services: The COVID-19 pandemic led to the partial or complete disruption of treatment services for hypertension (in 53% of 163 WHO member states), diabetes and diabetes-related complications (49%), cancer (42%) and cardiovascular emergencies (31%) (1).

Food security: COVID-19 was projected to double the number of people facing food crises in low and middle-income countries to about 265 million by the end of 2020 (1).

Poverty: COVID-19 was projected to push 71-100 million people into extreme poverty in 2020. Long-term progress in poverty reduction is about to be reversed, conflicting with the UN SDG target to eradicate extreme poverty by 2030 (1).

Most of these impacts are caused by disruptions to economic activities, transport and social contacts. Such disruption can emerge through lockdown policies or through a disorderly process of contact avoidance and loss of trust. In low and middle-income countries, decision-makers often face a grim dilemma to choose between allowing the virus to take its death toll or to put food security and non-COVID health care at risk as a side-effect of a lockdown.

An early model scenario indicated that without mitigation measures, the COVID-19 pandemic could have claimed approximately 40 million lives in 2020, but with mitigation measures, the death toll could have been reduced to around 4 million (1) (see also our article on the study). This was close to a later, more elaborate modelling of 2.09 million reported deaths and 4.19 million total deaths by end 2020, taking the countermeasures applied into account. By April 2022, the same model projects 6.59 million reported deaths or 13.9 million total deaths. Different scenarios of this study show that more severe courses of illness from the Omicron variant would lead to a higher death toll, while a third dose of the vaccine or less hesitancy against vaccination would result in a slightly smaller death toll, and 80% mask usage would reduce it even further (2) (see diagram below). This may be due to the fact that face masks can be produced and distributed faster and take effect faster than vaccines.

In the coming months it is absolutely critical to uphold or extend prevention measures such as mask wearing and physical distancing while also continuing and extending COVID-19 vaccination programmes, as they appear not to be sufficient to achieve and maintain herd immunity so far.