Published: Nov. 3, 2022 By

To end the “persistent and dangerous global health threat” of COVID-19, the world must take a “vaccine-plus” approach, which includes improved indoor air ventilation and filtration, and increased masking, testing and treatment. That’s just one of 57 recommendations included in a new study published today in the journal Nature by 386 multidisciplinary experts from more than 100 countries and territories. 

The authors agreed that there are many immediate and near-term actions that government leaders, businesses and the public can take to end the threat without exacerbating socio-economic burdens or putting the most vulnerable at greater risk. These include cross-disciplinary pandemic preparedness and response, addressing pandemic inequities, rebuilding public trust and combatting false information. 

They were also almost unanimous in their consensus that indoor areas with poor ventilation present the highest risks of transmission.

“Unfortunately, COVID-19 is not yet over,” said Jose-Luis Jimenez, co-author of the study, distinguished professor of chemistry at CU Boulder and fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES). “But there are many things we can and should be doing about it here in the U.S. and across the world, and a high priority should be paying attention to and taking action by cleaning our indoor air.”

Jose-Luis Jimenez

Jose-Luis Jimenez, distinguished professor of chemistry at CU Boulder and fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES).

Finding consensus

The findings of the consensus study, led by the Barcelona Institute for Global Health, have been endorsed by over 180 organizations worldwide. They come more than 2.5 years into the COVID-19 pandemic, as SARS-CoV-2 continues to circulate globally at unacceptable levels, threatening public health and straining health care systems.

As of October 2022, more than 630 million COVID-19 cases and over 6.5 million deaths have been reported—although the real death toll has been estimated to be upward of 20 million. In addition, millions of patients with cancer and chronic disease have experienced dangerous healthcare delays, and long COVID-19 continues to elude definitive treatment, posing an ongoing threat to survivors. The virus also continues to mutate and evade immunity. 

Due to the large number of experts consulted, the wide geographical representation and the consensus-building study design, the study may prove to be a model for responding to future global health emergencies, said Jeffrey Lazarus, lead author and coordinator of the study, and researcher at the Barcelona Institute for Global Health.

The panel of experts carried out a Delphi study, a research methodology that challenges experts to garner consensus on answers to complex research questions. The multidisciplinary panel of academic, health, NGO, government and other experts created a set of 41 statements and 57 recommendations across six major areas—communication, health systems, vaccination, prevention, treatment and care, and inequities—directed at governments, health systems, industry, and other key stakeholders.

The highest-ranked recommendations emphasize the need for coordinated strategies by both societies and governments to avoid fragmented efforts and make health systems more responsive to people’s needs. It also highlights a “vaccines-plus” approach, as 97% of the experts agree that vaccines alone are insufficient to end COVID-19 as a public health threat. Other recommendations with at least 99% agreement by the authors include communicating effectively with the public and engaging communities in managing the pandemic response. 

The paper emphasizes health and social policy recommendations that can be implemented in months, not years, to help bring this public health threat to an end, according to Quique Bassat, co-author of the study and ICREA professor at Barcelona Institute for Global Health. 

Airborne agreement 

The experts overwhelming agree that the SARS-CoV-2 virus is primarily transmitted through the air in a smoke-like manner—not through heavy respiratory droplets that quickly fall to the ground, or by touching surfaces—and should be addressed accordingly. 

“The airborne acknowledgement is very important,” said Jimenez, who is a leading expert in the airborne transmission of COVID-19. “Understanding and acknowledging how this virus primarily transmits between people is vital to its prevention. It is also critical for communicating accurate messages about how to stop contracting and transmitting this deadly and disabling disease.” 

Structural changes such as improving indoor ventilation and air filtration are even more critical now, he said, as those most at risk of severe disease can no longer rely on others to practice basic prevention measures, such as wearing masks or isolating when testing positive for COVID-19. 

96% of the authors agree or somewhat agree that wide use of high-filtration and well-fitting face masks (such as N95s, KN94s, KN95s and FFP3 respirators) are important to reduce transmission, especially in high-risk settings like hospitals, indoor bars and restaurants, gyms and any space with talkative or highly active unmasked groups of people. 

Jimenez notes that opening building and car windows, using portable air filters (such as HEPA filters or low-cost Corsi-Rosenthal boxes), and upgrading air filtration systems in a building’s HVAC system to MERV13 filters (which can capture very fine particles) all improve indoor ventilation and air filtration. 

Joshua Barocas

Joshua Barocas, associate professor of infectious disease and internal medicine at the University of Colorado Anschutz.

A compounded threat for public health and healthcare

The pandemic is still disproportionately impacting vulnerable populations, and without addressing the inequities involved, it will continue to be a public health threat around the world, said Joshua Barocas, co-author on the paper and associate professor of infectious disease and internal medicine at the University of Colorado Anschutz.

“This is perhaps the area by which every other public health response needs to be measured against. Are we just providing vaccinations? Or are we making sure that anyone who is eligible for a vaccination can get it?” said Barocas. 

Comprising two of the top 10 recommendations, the study states that “pandemic preparedness and response should address pre-existing social and health inequities,” and that low and middle-income countries need better access to technologies that allow them to develop and maintain their own affordable vaccines, tests and therapeutics. 

The authors note that the COVID-19 pandemic has also compounded other infectious disease outbreaks, like Ebola, Monkeypox, Polio and HIV, as well as other public health crises, such as antimicrobial resistance, drug overdoses, housing insecurity, gun violence, war and famine. It has also put unsustainable strain on health care systems globally, affecting access to and quality of care for both acute and chronic health conditions. 

“If we don’t address the systemic issues and collateral damage of COVID-19 as a public health threat, that puts us all at risk for worse health outcomes in general,” said Barocas.