Three corona vaccines already on the starting blocks after six months: are these rapidly developed vaccines safe?

Interim results have already shown three corona vaccines to work well. The world breathes a sigh of relief. But are those vaccines safe after just six months of development? We can reassure you: the answer is yes.

We have been bombarded with vaccine news in recent weeks. Every Monday a different vaccine company comes with preliminary results of its vaccine. Pfizer and Moderna both have an effectiveness of 95 percent, AstraZeneca keeps it at 70 percent, but that requires some nuance.

The tests were conducted according to two methods. One group was given a half dose first and a full dose a month later. It was 90 percent effective. Another group received two full doses a month apart. It was 62 percent effective. As a result, AstraZeneca reached an average of 70 percent.


But it cannot be ignored that all those vaccines have been developed very quickly. In November 2019, the first human was infected with the corona virus in the Chinese city of Wuhan, but then the urgency was not nearly as great. It was only when the first cases in Europe and the US came to light that pharmaceutical companies started to look at whether a vaccine is needed. They only really started researching around March.

Six months later, those vaccines are ready to enter the market. This is striking, because it can normally take up to ten years to develop a working vaccine. The fastest vaccine ever developed to date was that for mumps, which also lasted four years.

And yet we can tell you not to fear. If approved, the vaccines will meet all safety regulations.


To understand that, you should know that coronaviruses are actually a group of influenza viruses with potentially serious consequences. Some cause the common cold, others don’t affect people at all. But some can also be deadly, including this variant. The SARS virus from 2003 and the MERS virus from 2012 are also coronaviruses.

And that is immediately the first reason. “Pharmaceutical companies already had a lot of experience with vaccines against SARS and MERS. These focus on the same protein in our body, the well-known spiny protein, which has already laid the foundation for the current vaccine ”, says vaccineologist Isabel Leroux-Roels of UZ Gent.

New technology

In addition, new technologies have also been developed in recent years that accelerate development. The so-called messenger RNA, in which a piece of genetic material from the virus is injected into the body, was discovered in the 1980s, but research into it only gained momentum in 2006 after the discoverer was awarded a Nobel Prize. It now faces its big break. The advantage of this is that the virus no longer has to be grown all by itself, but that a piece of genetic material is enough.

The other technology is the viral vector, in which a piece of the virus is sent into the body via another harmless virus. For example, the American-Belgian Johnson & Johnson uses a cold virus in chimpanzees against which it has already developed a vaccine. “Johnson & Johnson already had experience with 60,000 people and was therefore granted authorization to start its trials for this vaccine more quickly. But there is also the example of the German CureVac that had no experience at all with messenger RNA. He just had to go through all the normal steps. ”


According to Leroux-Roels, it is also a misconception that people are followed up for ten years in other cases to check for side effects. “That is never the case. Such a study lasts a maximum of one year, because most side effects are expected in the short term. “

But what makes the development take so long? “It’s a matter of priorities”, it sounds. “We have now also suspended some studies with other vaccines because the corona vaccines must be given priority. And the pharma watchdogs are now prioritizing corona vaccines. Normally, such an approval takes seven months, but that’s not because they spend seven months looking at it day and night. That just ends up in a large pile of files and only after a few months someone looks at it. ”

Sun vaccine

Leroux-Roels gives an example from her own career. “Years ago I worked on a vaccine against the contagious skin rash zona, but by the time it was almost ready it had been in the fridge for three years when the bird flu and the swine flu came between them and demanded more attention. But if that had not happened, that vaccine would also have been on the market much earlier. ”

The vaccineologist emphasizes that we should not fear for the safety of current vaccines. “Of course, very rare side effects can still be found in the long term, but that chance is really small. It is irresponsible to withhold the world from a vaccine based on those purely theoretical risks. ”


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