Read the letter one of Belgium's top virologists sent his children on how they can safely get on with their lives

• Peter Vanham lives in Geneva, Switzerland and is the head of the International Media Council at the World Economic Forum and a member of its COVID-19 Taskforce.
• His father, Guido Vanham, is a Belgium-based virologist, a microbiologist who studies the rapid spreading of viruses.
• Guido Vanham sent a letter to his three children with tips for how to combat 'fatigue' from following COVID-19 restrictions and for how to stay safe as areas of the world begin to reopen.
• He advises taking off masks when outdoors and away from crowds, opening windows as much as possible, and shielding children from lockdown: 'Kids need to go to school.'
• The full text of his letter is shared below, with permission from Vanham's son, Peter.

Dear Peter, Johan and Nele,

I hope you are all well.

It is so good to hear you all doing so well. Johan, Roxane, Nele, and Jeffrey, we're happy to see the kids back in school, and Peter and Valeria, it's good that you are doing so well in Geneva. It's been about half a year since the COVID pandemic started, and I understand you must have "COVID fatigue" by now. So let me offer you some advice and tips on how to go about your daily lives in the coming months. It's needed, I reckon, because we still have a way to go.

First, I want to warn you to not react with extreme thoughts or debates. You may think it's "annoying" to have to wear masks in more places again now that confirmed cases are rising again, or be asked to see less people, or to stay away from crowded indoor spaces. You may think that the risk of this "second wave" becoming more deadly is overblown.

Or you may think the opposite — that we should lock down all social life again, including schools, workplaces, and restaurants. You're free to think all of these things.

But remember: The virus doesn't think. We cannot make a "compromise" with this virus.

The virus doesn't negotiate about its conditions for spreading, and it doesn't make concessions after six months just because you've already given up a lot of your social life for a lengthy amount of time. It also doesn't care about politics, or about arguments in either direction. It is quite the opposite: It will find the "weakest link" in our defense to it, and spread again from there.

There are two characteristics about the transmission of this virus that are particularly annoying.

• First, it does not only spread by droplets from coughing or sneezing (that fall down within a meter and a half or six feet), but also by small aerosols, produced by speaking, that can float in the ambient air unless dispersed.
• Second, many people who remain without symptoms can spread the virus. Some of these are in fact becoming so-called "super spreaders," infecting, unknowingly and inapparently, sometimes dozens of others.

So let's continue to be vigilant, all while restarting our social, educational, and professional lives.

And if you don't want strictly following government orders on the virus, or adapt to ever changing rules, but you do want to help contain the virus, here are a couple of measures you can take for yourself in the coming months, and until there is an effective vaccine or treatment.

• Wear a mask that fits your face well and has a filter; that way it becomes more effective. It's abundantly clear that wearing an effective mask is the single best measure against getting or transmitting the virus, while maintaining public life. But masks aren't all the same! Some will be too large, leaving an opening on the side, whereas others may not have a double layer and filter, which is crucial to make it effective. So choose ones that are best adapted to your face, and that don't leave any unfiltered air in or out. And remember to wear them over your mouth and nose — this will truly make a difference. Even if masks don't fully stop transmission of the virus, they can stop most of the virus particles, and that matters: If you get only a small amount of virus, the virus multiplication will take longer to become harmful, giving your body more time to set up immune defense mechanisms. It can ultimately mean the difference between mild and heavy symptoms — or life and death.
• Wear your mask indoor or wherever large crowds gather outdoors; feel free to take it off elsewhere. There is now enough evidence to suggest that virus particles disappear much, much quicker in open air than in closed spaces. So Peter, I wouldn't stress too much about outdoor activities with others, such as running or soccer, as long as you don't get close to others when they yell or cough. But when you're at the office with others, or in the bus or subway, keep a distance, wear your mask, and disinfect your hands.
• Meet outdoors and open windows as much as you can, both in your social and work life. We were very happy to come visit you in Switzerland, going for hikes in the mountains and enjoying time together. Although we're older, and therefore more at risk, we felt comfortable, as we were mostly outdoors, and when we sat down, windows were always open. So if you're looking for a balance in your social and professional life, let that be your focus as well. And if opening windows isn't possible, inquire about the air circulation (for example: is it fed with fresh air or are efficient carbon filters in place?), and wear a mask diligently.
• Put the children first. If anyone needs to be shielded from a next "lockdown," it's them. Nele and Johan, I know this has become a heated debate, but please put the wellbeing of the children first. Kids need to go to school, and while they are unlikely to get sick, of course they can become virus "vectors." But the answer can't be to put them in lockdown again. At their age, they need to learn. So if we need to take stricter measures again, let it be us, as adults, who lock down. You can tele-work; for children, it's much harder to tele-learn.

I also want to give you an update on the situation in hospitals, treatments, and vaccines.

Right now, we [in Europe] are clearly in a "second wave" in terms of infections, but much less so in terms of deaths. Why is that? Well, in our hospitals, there are mostly young people being cared for because of COVID-19 — and it is mostly the young who test positive, too. Those that do end up in hospitals are often severely ill, but survive, because their bodies can fight off the virus with rest, medical care, and if needed, oxygen supply.

This is what you could call a "dangerously stable" situation. As long as older people and those with underlying conditions don't get infected in large numbers again, our hospital systems can cope and not many people will die. But right now, as could be expected, we see the numbers of older infected people rising as well.

So clearly, the situation can turn around in a matter of a few short weeks if we become careless.

This for example happened in Spain, which went into lockdown again after the situation got out of control for a second time. People got too "active" again, and inevitably, not just younger people got infected, but over time, the elderly and sick too, leading to a dramatic turnaround, and again many deaths. It can happen here too.

So if you become tempted to relax your own attitude towards the virus, bear in mind that at this very moment, we don't have a vaccine, there's still only one truly effective treatment, and it is limited in supply — oxygen through respirators — and the virus can quickly start spreading exponentially again, putting at risk the most vulnerable in our population.

Finally, in terms of vaccines, I share the general optimism that one or several vaccines will be available by the first half of 2021.

What gives me hope is that the SARS-CoV2-virus (which causes COVID-19), looks a lot like other coronaviruses, such as SARS, for which effective (experimental) vaccines were developed. And the techniques used for other vaccines in the past, including the straightforward inactivated virus vaccine, and the vaccines targeting the "spike" of the virus, seem to be working as well. All of this means that we should be seeing vaccine candidates clearing the final hurdles by early next year.

But let's immediately put some caveats. First, in terms of production and distribution, it will take months, if not years, before enough people globally can be vaccinated. In the West and China, it will be a big success if we can vaccinate enough people by the end of 2021 — more than 50% of the population need to be vaccinated to achieve "herd immunity" for the others. In other parts of the world, it will surely take several more years. So "normality" is still at least a year and a half away.

And, from a virus-technical perspective, we still cannot be sure that the vaccines developed today will remain effective against the virus in a few years from now. So far, the evolution of the virus has been limited, but things could still go in various directions.

A positive scenario is that the virus could "weaken," as happened with a previous porcine (swine) coronavirus.

But on the negative end, the virus could evolve such that initial vaccines could become ineffective or even harmful, as happened with one feline (cat) coronavirus in the past. The positive or neutral outcome luckily seems more likely: it would mean that this coronavirus would persist, but infect the next generation of children early in their life and providing partial immunity, with mild disease, when they grow older. As of today, we can't be sure yet, so caution is advised: Let's make preventive measures our habit.

That's the gist of my advice and information to you. I hope this letter is helpful to you as you're going back to school and work. And I hope it can help you fend off your worries or frustrations over the virus with measures you can take regardless of the news of the day.

I'll be watching the evolution on a daily basis, because researching viruses is my passion. But for you, maybe it's good to not think about it too much, and just take those preventative measures that make you and others around you safer.

Be well,

Dad

Guido Vanham, MD, PhD, is the former head of virology at the Institute for Tropical Medicine in Antwerp, Belgium.

Peter Vanham is head of the International Media Council at the World Economic Forum, and a member of its COVID-19 Taskforce. He lives in Geneva, Switzerland.