For the best experience on the web, we recommend updating your browser.Update now!
There are 3 types of vaccines, which differ in the technique they use to encourage the body to produce antibodies:
Messenger RNA vaccines (a technique used since the 1990s in human vaccines and for a long time in the veterinary world): the vaccine provides the body with the genetic code needed to produce the spicules of the coronavirus - the 'spikes' that make it recognisable. Thanks to this code, our body produces its own spicules and then antibodies. This RNA does not integrate into our own DNA - it does not change our genome. Relatively fragile, it is introduced to the body’s cells within a lipid (a drop of fat), and needs to be stored at a very low temperature. The following vaccines are messenger RNA vaccines:
Viral vector vaccines (a very common vaccination technique): the genetic code of the coronavirus spicules is presented in another harmless virus (a previously weakened adenovirus). Thanks to this code, our body produces its own (harmless) spicules and then antibodies. This type of vaccine takes longer to produce than messenger RNA vaccines, but is easier to store.
Recombinant protein vaccines: these vaccines contain coronavirus spicules, previously isolated in the laboratory. When isolated they are harmless, but they are still insufficient to generate a correct immune response. In the vaccine they are therefore combined with an adjuvant: a chemical molecule that will give the immune system the warning signal to produce antibodies.
The Pfizer and Moderna vaccines are the first vaccines to be available in Belgium. The AstraZeneca vaccine should be available by the end of January 2021. The others are not yet available in Belgium.
These two vaccines use the same technology (messenger RNA) and generate the same high level of protection, but there are several differences between them.
The Moderna vaccine is intended for people over 18 years of age. The two doses are administered 28 days apart. Moderna vaccines can be stored for six months in the freezer (-20°C) and for 30 days in the fridge (2 to 8°C).
With the Pfizer vaccine, the age limit is 16 years. The two doses are administered 21 days apart. Storage is at -70°c.
There are no major differences in side effects.
Even though the vaccines are authorised on the European market, research is still ongoing. The manufacturer is required to provide additional information on the Moderna vaccine over the next two years. This will include communicating how long the vaccine provides protection for, how well it protects people with weaker immune systems, and whether the vaccine also prevents infection in other people.
No. Available vaccine doses are used to vaccinate priority groups. Europe has approved all these vaccines. The monitoring carried out by the European Medicines Agency (EMA) includes an in-depth study of all results by independent experts. They check that the information given by the company is demonstrated effectively. This ensures that claims that vaccines are safe are not based solely on the statements of those who produce the vaccines.
It is important that as many people as possible are vaccinated in order to achieve herd immunity. To do this, we need to achieve a vaccination rate of between 70 and 80%. However as a precautionary measure, for the time being specific groups are excluded from having the vaccine:
Further research is needed to determine if the vaccine is also safe for children and pregnant women. Women who are breastfeeding can be vaccinated. This is confirmed by recent data collected in the United States.
In cases where there is a history of a severe allergic reaction, if necessary the vaccine can be administered in a controlled environment (in hospital).
Experts on the Conseil supérieur de la Santé (Superior Health Council) are determining these criteria.
To ensure adequate protection, the current vaccines must be administered in two doses. This is the case with many vaccines, including those used against hepatitis A and B. A single dose of coronavirus vaccine is therefore not enough to ensure long-term protection. Every person who is vaccinated must therefore be sure to mark the date for the second injection in their diary.
Some people are concerned about the new vaccines, which is understandable. The speed with which they have been developed has left some people feeling confused. Have important steps been overlooked? Was the work rushed?
The answer is no: these vaccines have gone through all the necessary stages, just like other vaccines. The fact that several vaccines have been developed in such a short time is simply the result of an unprecedented research effort and collaboration. Dozens of laboratories entered the race and gave top priority to the development of a coronavirus vaccine. As COVID-19 is part of a family of coronaviruses (including SARS and MERS), few studies have had to start from scratch. Researchers relied on existing vaccines that have proven effective against other types of coronavirus.
Pfizer has published all the results of its study in The Lancet, a major scientific journal. Publication in The Lancet is only possible after thorough verification of the study by independent scientists from around the world.
The Pfizer/BioNTech vaccine instructions describe the following possible side effects: pain in the arm at the injection site, headache, fever, muscle aches and/or chills. These side effects may be unpleasant or uncomfortable, but they are not life-threatening. They are not out of the ordinary either: other vaccines can cause similar unpleasantness for some people.
The cause of these side effects is to do with the way the vaccine stimulates the immune system. On average, the unpleasant feelings last a day or a little longer.
We are still waiting to hear about the possible side effects of the other vaccines. Belgium has also placed orders with AstraZeneca and Johnson&Johnson, which use a different vaccine technology.
As with any vaccine, a serious allergic reaction can never be ruled out, but is very rare. Vaccination teams are trained and specially equipped to respond appropriately.
At the start of the vaccination programme in the UK, two health professionals with a history of severe allergic reactions had an anaphylactoid reaction (a severe allergic reaction) to the vaccine. They had a rash and difficulty breathing, but they are fine now. This type of reaction can occur in response to medication or a vaccine. Usually it is because the person is allergic to one of the components of a vaccine.
These reactions are rare and occur immediately after vaccination (5 to 10 minutes). This is why the protocols state that the vaccinated person must remain on site for a few minutes after receiving the injection.
A lot of data from clinical studies on possible effects after three or six months are already available. These data do not indicate any problems. As these are new vaccines, the longer-term effects are not yet known. Studies are in progress. Epidemiologists speak of a calculated risk, taking into account the severity of the infectious disease being protected against. COVID-19 seriously compromises the way we live and work, and with each new wave puts the health system under severe strain.
In addition, it is difficult to establish the link between a vaccine and possible medical problems beyond a period of two years (the duration of follow-up studies). The same applies to vaccines that have been around for a very long time.
No. The Pfizer/BioNTech and Moderna vaccines are RNA vaccines: They contain portions of the genetic code of the SARS-CoV-2 virus. These are the code portions of the "spicule" proteins typical of SARS-CoV-2.
After the injection, cells in the body absorb RNA from the virus. These cells then develop spicule proteins. The immune system reacts by producing antibodies (among other things). In the event of a real attack by SARS-CoV-2, the body will be equipped to neutralise the virus.
The RNA genetic code in the body's cells cannot change or damage human DNA, nor can it produce tumours. In fact it is not possible for a portion of RNA to integrate into our DNA. DNA consists of two strands, whereas RNA has only one. This makes them incompatible. The RNA will be broken down again and disappear.
Anyone who has contracted COVID-19 and has recovered will have antibodies in their blood for a period of time. Unfortunately they disappear quickly, along with the protection they provide. Cases of re-infection have been recorded around the world. We do not yet know how long a natural infection immunises against a new infection. Currently, studies are focusing on the duration of protection offered by the vaccine against the virus.
If you have been infected with COVID-19, you must wait for at least two weeks after the last symptoms have disappeared before you are vaccinated. This delay is intended to avoid possible residual symptoms of the disease being interpreted as side effects of the vaccine.
In addition, the vaccine is not just for your own protection. Those who are vaccinated are indirectly protecting others. The larger the population that is vaccinated, and therefore immunised, the wider the protective reach will be and the harder it will be for the virus to spread. We will only achieve herd immunity if 70-80% of the population is vaccinated. In the long run, herd immunity will be essential for resuming a normal life without restrictions on social contact.
Coronavirus vaccines from Pfizer/BioNTech, Moderna and AstraZeneca appear to offer good protection against COVID-19. In the event of contact with a contagious person, the probability that you will be protected with the AstraZeneca vaccine is 70%. With the Moderna and Pfizer/BioNTech vaccines, this probability is over 90%. The vaccine greatly reduces the risk of falling ill but will not completely eliminate it as long as the virus is still circulating.
However, some aspects remain uncertain. For example, we do not yet know how effective vaccines will be for specific age or at-risk groups. The duration of protection provided is also unknown. It is possible that the vaccines do not offer lasting protection. Another important aspect that we are not yet aware of is whether the vaccine also stops someone who is asymptomatic from being contagious. In other words, if it is still possible to spread the virus even though you are protected yourself.
Vaccination therefore does not necessarily mean that preventive measures can be lifted.
With the Pfizer vaccine, antibodies appear 7 to 12 days after the first dose. The second dose is injected 3 weeks after the first, and antibody production follows again 7 to 12 days later. A vaccinated person is considered to be immunized two weeks after the second dose. The timelines would be similar for the other current vaccines.
It is not surprising that the coronavirus mutates. This is common with viruses. A mutation is the result of a "writing error" during virus replication. There are potentially dozens of mutations at this stage.
A mutation could also become the dominant strain. It is already clear that the British variant of COVID-19 is much more contagious (between 30 and 70%). In terms of the degree of severity of illness or risk of death, there is no difference from the other variants.
It appears that the Pfizer/BioNTech and Moderna vaccines also offer sufficient protection against the British and South American variants. It is possible that current vaccines offer a lower degree of protection against certain mutations. This issue is the subject of further research.
It is not yet clear how long the current coronavirus vaccines (Pfizer/BioNTech and Moderna) will provide protection. Research on this subject is ongoing.
The surveys carried out show regional differences. About 70% of the population is in favour of the vaccine in Flanders, and about 50% in Wallonia.
At present, there are no plans for this. Vaccination remains voluntary.
No, for several reasons. First of all, you will not be protected and will still be at risk of infection. Secondly, by having the vaccine you are not only protecting yourself, but also vulnerable people, such as cancer patients or pregnant women. If too many people wait and rely on others, it will take a long time to achieve herd immunity. Or worse: we may never reach it. If we want to return to a more normal way of life, broad vaccination coverage (70 to 80% of the population) is essential.
It is important to stress that all the necessary steps for the development of coronavirus vaccines have been followed. The speed of their development does not mean that control stages have been neglected. The vaccines were therefore extensively tested before receiving the green light.
Although it is always advisable to adopt healthy lifestyle habits, there is no way to boost one's immune system to no longer be vulnerable to the coronavirus. Excess weight and high blood pressure increase the risk of severe reactions in case of infection, but no one is invulnerable. Vaccines have already proved very useful in the past in the fight against serious diseases such as measles and polio.
Unfortunately, this risk will remain for some time to come. Millions of Belgians (70-80% of the population) need to be vaccinated if herd immunity is to be achieved. Even if enough people are willing to be vaccinated, the vaccination programme will take a good part of 2021 before it is completed. As vaccination coverage increases, we will be able to relax prevention measures. But we will have to live with the threat and inconvenience of the virus for some time to come.
Visit the laatjevaccineren.be and gezondheidenwetenschap.be websites, where you will find information that is scientifically accurate.