Even with a vaccine, we are still far from rid of...

The first corona vaccines could be approved at the end of this year. But there are still many unanswered questions about the effectiveness and distribution of these vaccines.

When will we be able to travel, dance and cuddle carefree again? When will we get rid of those wooden elbows and annoying mouth caps? When do we return to the old normal? Since the start of the corona crisis, we hear only one answer to all these questions: “when the vaccine is available”. Never before have we craved such an injection. But is all that hope justified? Will the vaccine bring us back to our familiar life like a light switch or will we be saddled with this virus for a long time?

Let’s start with the good news. More than 240 different vaccine candidates have already entered the global race for the corona vaccine. Eleven of these candidates are now in phase 3 of the investigation. That means that about 30,000 to 50,000 people were given either the corona vaccine or a placebo. Subsequently, the subjects lead their normal lives, and the researchers monitor whether people with the vaccine are spared the coronavirus and unpleasant side effects.

The front runners in the race – the Oxford / AstraZeneca, Pfizer / BioNTech and American Moderna teams – are expected to publish the interim results of that test phase within weeks. “Everyone is looking forward to that. That will be the first time that we will really see how well the candidate vaccines protect against the virus ”, says virologist Johan Neyts of KU Leuven. If those results show that the candidate vaccines are safe and effective, the international health authorities can give permission for the vaccines to be marketed. Then things can go quickly, because some candidates who are in phase 3 have already started with a lot produce vaccines.

False feeling

There is no consensus about how efficient the vaccines must be to be allowed to enter the market. The British team from AstraZeneca and Oxford sets the bar at 50 percent, which is also the minimum set by the World Health Organization (WHO). The European assessment body EMA does not work with a predetermined minimum mark, but looks at the balance between effectiveness and risk. Administering a vaccine that just passes the WHO threshold of 50 percent is not without risk. Because if only half of the vaccinees are effectively immune, a false sense of security can develop and the skepticism of those less inclined to corona vaccine is further fueled.

“Even so, a vaccine that is only 50 percent effective is better than nothing,” says epidemiologist Pierre Van Damme (UAntwerpen). “If you can reduce the number of hospitalizations or protect the health care staff, that is important. ” A vaccine with an efficacy of 50 percent could, according to Van Damme, influence the priority list. “As should you get those vaccines first and who better to wait for a possibly better vaccine? That’s an ethical discussion that must then be conducted.

Of course, there is a good chance that one of the candidate vaccines will be more than 50 percent effective. Then there are still unanswered questions. How long will the vaccines provide protection? And do the vaccines also provide sufficient protection against the serious Covid-19, which causes people to end up in intensive care or, in the worst case, die? Test phase three is too short and too small to obtain an accurate picture of this, which means that the clinical picture is less common. “It is precisely that smaller percentage of severe covid infections that causes the greatest problems. If the vaccine would primarily protect against mild infections earlier, then we are still a long way from home, ”says virologist Johan Neyts.

Logistics feat

In addition to the unanswered medical questions, an unprecedented logistical challenge lies ahead to distribute the vaccines. Since vaccines must be transported and stored at temperatures from -20 to -80 ° C, there is a need for refrigerated loading trucks and storage space. Vaccines do not come in individual doses, but in large bulk packages to be used within a few hours. “Then you have to use tent camps, with the help of the army, or use schools on the weekends as vaccination centers. We can also send in letters to invite people by profession for their vaccination. It is almost like election days ”, says Pierre Van Damme.

How quickly we achieve the desired group immunity with the vaccines also depends mainly on how many people want to vaccinate themselves. American researchers calculated that a vaccine with 60 percent efficiency is sufficient if the entire population is vaccinated. If only 75 percent of people are vaccinated, then the vaccine should be 80 percent effective. “Our barometers show that people’s willingness to vaccinate varies between 70 and 90 percent. It will be important to communicate very transparently about where we stand with the vaccine, ”says Van Damme. In any case, we will also have to live with mouth masks and distance rules with the vaccine. “First you have to focus on individual immunity. We will probably not be able to build up towards group immunity until the autumn of 2021. ”