Covid, the fifth option to beat the virus, according to the WHO- breaking latest news

The Covid pandemic has started to run again around the world with over 277 million cases and almost 5 and a half million victims. The decline in the effectiveness of vaccines over time has prompted many countries to proceed with third and even fourth doses in an attempt to protect the most fragile and avoid infections even among vaccinated. Omicron is scary because it is transmitted with extreme speed and even if the consequences on health seem to be milder (thanks to the large number of vaccinated people), hospitals risk going into trouble. Many infected do not know why they are, and the chains of contagion are difficult to reconstruct with the exception of super-diffusing events (Christmas dinners, school outbreaks). Winter is still long, and a lot of time will have to be spent indoors, where the virus spreads very easily. Vaccines, hand washing, distancing, masks: everything has been done, and even if in Italy the deaths are much lower than a year ago, the infections are greater and are growing more and more. The virus kills less, but it’s still with us.

Can we still do something to get rid of it? The fifth option is called ventilation and now the World Health Organization also aims to communicate its importance and invites everyone not to neglect an opportunity that could prove to be a winning one to mitigate the risk of infection in closed environments.

We talked about it with Luca Fontana, toxicologist, technical officer of the World Health Organization who deals with engineering environmental controls for Covid treatment centers.

To understand how to combat it, we must first understand how Covid is transmitted: what is the main way of contagion?

«Sars CoV-2 is an airborne virus and infection occurs through exposure to infectious respiratory fluids released as particles of different sizes during exhalation. While larger particles settle rapidly, smaller ones remain suspended in the air for a longer period.

When people are in the immediate vicinity of an infected person, transmission can occur by direct inhalation and by depositing infectious particles on exposed mucous membranes. In poorly ventilated or crowded enclosed areas, these infectious particles can accumulate in the air and be inhaled: also as the closeness to the infected person increases
the concentration of aerosols also increases
and consequently the risk of infection. Currently, there is limited evidence of transmission through surfaces (objects or materials that can be contaminated by viruses such as tools and furniture) in the environment surrounding the infected person ».

Are vaccines not enough to defend us?

“Regardless of the transmission mode,
vaccines help our immune system protect us from severe forms
, but we know that theimpact on transmission is limited: they are effective in protecting us from serious illness and death, but they are not as capable of defending us from infection, therefore the virus continues to circulate in the community, although many people remain asymptomatic. With Omicron, we are seeing an alarming number of reinfections. It is not a defeat of vaccines because they maintain the crucial function of reducing pressure on the health system, ma the circulation of the virus is preventing us from regaining possession of our life and could favor the emergence of new variants ».

And the masks?

“How hand washing and other precautions help reduce the possibility of infection but not eliminate it. Surgical masks, but even more so FFP2, help reduce the amount of aerosol inhaled and to prevent larger particles from depositing on the mucous membranes, but they do not eliminate the risk with a high concentration of particles in the air and long periods of exposure. Furthermore should be worn correctly and systematic indoors, which doesn’t happen so frequently. We think of the schools and offices where students and workers spend long days. And also to other closed environments where for one reason or another we cannot wear a mask, such as restaurants. All ‘opened the aerosol is almost immediately dispersed and diluted in the air, for this reason very few infections are observed compared to closed environments ».

Are there other ways to get out of the pandemic?

“Continue with distancing, good hygiene practices, the use of masks, vaccination but certainly increase the commitment to ensure the management of the contagion risk also through a correct and adequate ventilation of the premises. The ventilation allows to reduce the concentration of infectious aerosol in the air and therefore reduce the risk of infection ».

But what does it mean to ventilate? It consists in bringing fresh and clean air from the outside to the inside and sending the exhaled air, together with the infected aerosol, outside. An important engineering measure of risk mitigation is the
controlled mechanical ventilation
, but it is also possible to intervene simplyand ventilation, i.e. opening the windows. This second option, however, in addition to the significant energy and environmental costs for thermal dispersion, does not allow any checks on the effectiveness of the protection measure “.

In recent years, taking a cue from indoor air quality problems, i air purifiers, that is systems that, by filtering the internal air, reduce the risk of contagion. Of course, they are not a permanent solution and ventilation remains the first option. A promising solution for the cost containment and the personal ventilation, or air changes limited to the breathing area of ​​each subject when in a fixed position “.

But haven’t respiratory diseases always been fought with vaccines?

«In general, respiratory disease or not, vaccines have been a big breakthrough for public health. We think aboutsmallpox eradication and the type 3 poliovirus which causes, indeed, caused the polio. However, history teaches us that the vaccine is not always the magic solution. Sometimes it took environmental interventions to reduce or eliminate a disease. Interesting examples are cholera, yellow fever and malaria. In many countries, cholera has been eliminated through improvements to the water distribution system
and on the sewer system. Yellow fever and malaria through remediation works. It took years and important investments but today we no longer have epidemics of cholera and malaria in Europe for example ».

Equipping a building with controlled mechanical ventilation is a huge investment, will we be repaid by the costs?

“How much is this pandemic costing us? The cost in human lives is simply incalculable, a disaster. But in economic and social terms we can imagine what the costs are. Very high. Therapies, hospitalizations, indirect deaths of those who did not have access to health care in addition to all the economic activities that suffer and the stock exchanges that collapse: all are paying the negative consequences of Covid. The pandemic has upset our lives, our economies and we must put ourselves in the order of ideas that we will not get out of this situation anytime soon. We need a structural change in the approach to the pandemic, we have to start thinking long term.

It is evident that we cannot think of creating a controlled mechanical ventilation system in all buildings overnight. But it’s important to start. We could begin to evaluate the state of ventilation, improve it or reduce the occupation of space. And also better communicate the importance of ventilation to mitigate the risk of infection. Today we can see the list of allergens in any restaurant but we do not know if it is equipped with efficient ventilation: we must aim for that.

However high the initial investment may be, it will still be acceptable when compared with future benefits. It is then up to governments to choose whether and how to encourage this change. After all, in Italy there is a 110% renovation bonus that is being talked about a lot these days: why not include ventilation among the possible works?

Would ventilation bring extra Covid benefits?

Respiratory diseases are the leading causes of death and disability in the world. About 65 million people suffer from chronic obstructive pulmonary disease (COPD) and 3 million die from it each year, making it the third leading cause of death worldwide. About 334 million people suffer from asthma, the most common chronic childhood disease affecting 14% of all children globally. Pneumonia kills millions of people every year and is a leading cause of death among children under 5. Over 10 million people develop tuberculosis (TB) and 1.4 million die from it each year. Improving the quality of the air we breathe would bring huge benefits to our lives and could mitigate the risk of infection not only from Covid, but of all other acute and chronic respiratory diseases ».

Is it possible to install a controlled mechanical ventilation system also in historic buildings?

“I imagine that our engineering colleagues will be able to help us in this but, even if it were not possible, we could always reduce the maximum occupancy of the rooms by adapting the number of people in closed spaces to ventilation”.

Why hasn’t the WHO communicated the importance of ventilation more incisively?

“It is true that little emphasis was placed on airborne transmission outside of healthcare settings at the beginning. All ‘onset of the pandemic the mode of transmission was thought to be through droplets and that the aerosol had a marginal role. The issue has been the subject of great debate within the WHO, which however has always recommended ventilation and spacing as measures to mitigate the risk. Unfortunately, to date we do not have a defined methodology to say if a pathogen is airborne or not and for this reason the scientific debate was particularly heated»

What is WHO doing now to promote ventilation?

We have been working with various experts since 2020 and some technical documents have already been published. The ” ventilation roadmap ” for example provides concrete recommendations on how to improve internal ventilation. Another important work is currently underway. For some months a work group made up of virologists, infectious diseases, engineers, architects, physicists has been working on how to quantify the risk of Covid air transmission. There are two projects: the first aims to create a physical model to be provided to governments on the basis of which they can orient themselves to develop ventilation standards in public environments. At the moment, for example in restaurants, ventilation should not only refer to odor and temperature control as is the case now, but a ventilation standard that is specific to the infection will have to be introduced. The second project is a tool available to everyone thanks to which it will be possible calculate the risk of infection. To give an example, if I wanted to organize a dinner at my house, I can enter the data with the size of the room, the number of guests, the existing ventilation or the size of the windows. The tool will tell me what the real risk is in my home, it can advise me to limit the number of guests or it will tell me how long to open the windows every hour to mitigate the risk of contagion. The model will have to be validated before it can be published e we hope to be able to make it available in the first months of 2022 ».