Darrick Robles After months of intensive research, there are now two approved vaccines against Covid-19 in Germany – and more than 100 other vaccines are currently in development. Here you will find answers to the most frequently asked questions about the Pfizer/BioNTech and Moderna vaccines.
How do vaccines work?
Vaccines work in two ways – they either contain a weakened or inactive part of a virus or bacterium, or a “blueprint” to make that virus or bacterium. The substances cannot cause the disease that is being vaccinated against. Instead, vaccines trick the body into thinking that it has a specific infection so that the immune system starts making antibodies to fight that infection. Then, when you come into contact with the virus or bacterium, your body is already primed to defeat it.
How do the Pfizer/BioNTech and Moderna vaccines work?
Both vaccines use the blueprint approach and use messenger RNA (mRNA). This is a genetic code or “message” that the human body decodes to form appropriate proteins. The coronavirus has proteins spread all over the outside of its envelope, giving it its spiky appearance. The vaccines contain the code for these spike proteins, based on which our body can make these proteins itself. Our immune cells (B cells) encounter these proteins and recognize them as dangerous, so they start making antibodies that attack the virus directly. Other immune cells (T-killer cells) also read this code and immediately destroy cells infected with the coronavirus.
Can mRNA vaccines change the human genome?
The mRNA from the vaccine is not very stable. It breaks down naturally and is eliminated completely within a few days of being injected into the body . It is just a “message” that is not built into the DNA of the human body. Consequently, it cannot cause an infection with Covid-19. The genome is not changed either, since mRNA vaccines do not affect either egg cells or sperm.
The immune system has now memorized the code and can react quickly if it comes into contact with SARS-CoV-2 in the future.
Why are transport and storage so complex?
The specialty of the Pfizer/BioNTech and Moderna vaccines is the fact that the mRNA code for the injection is encapsulated in a lipid sac. This is very fragile and easily destroyed if not stored under the right conditions. Therefore, the vaccines must be transported and stored at temperatures of -70 °C (BioNTech) or -20 °C (Moderna). An advantage of the Moderna vaccine is that it is expected to be stable for up to 30 days at 2°C to 8°C – making storage and transport a whole lot cheaper.
How was it possible to develop the vaccines so quickly?
Covid-19 shares many similarities with the SARS virus – an infection that was rampant in 2002-2003. Because the genetic code of SARS and Covid-19 was similar, scientists had a head start in developing the Covid-19 vaccine. Much of the preliminary work had already been done.
It also helped that never before in the history of vaccine development has the entire scientific community worked so hard and united towards a common goal – and had access to so much funding. When manufacturing a vaccine, applying for funding and recruiting enough volunteers willing to be injected with the vaccine typically takes the most time. In addition, there are often difficulties in assessing the effectiveness of a vaccine because the infection against which it immunizes may not be particularly common in the general population.
None of these problems have arisen with the Covid-19 vaccine: funding was readily available, there were many volunteers wanting to test the vaccine, and we are in the midst of a pandemic right now, so the effectiveness of the vaccine can be easily demonstrated. All of this has made it possible to rapidly advance the development of vaccines.
How safe are the vaccines against Covid-19?
The STIKO (Standing Vaccination Committee at the Robert Koch Institute) rates both vaccines as equally safe and equally effective and recommends them for protection against Covid-19. One difference is that the BioNTech-Pfizer vaccine is approved for patients over the age of 16 and the Moderna vaccine only from the age of 18.
The Pfizer/BioNTech and Moderna vaccines have gone through multiple phases of vaccine testing — Phase 1, Phase 2, and Phase 3 studies. Data from the BioNTech vaccine study shows that over 40,000 people have received the vaccine with no serious safety concerns observed. The Moderna vaccine trial involved more than 30,000 subjects, half of whom received the vaccine.
How are the BioNTech and Moderna vaccines administered?
It is administered by injection into your upper arm muscle. Both BioNTech and Moderna require two vaccine doses. The vaccinated receive the second dose 3 weeks (BioNTech) or 4 weeks (Moderna) after the first vaccination. The data so far suggests that the BionTech remedy provides 95% protection against Covid-19 7 days after administration of the second dose. The effectiveness of the Moderna remedy is almost identical: it is 94.1% 14 days after the second dose.
What are the side effects of the BioNTech and Moderna vaccines?
The Covid-19 vaccine can cause side effects similar to those of other vaccines (such as the flu shot). These side effects include:
- pain at the injection site
- fatigue
- headache
In rare cases, fever has occurred. Most side effects are mild and only last a few days. The vaccine is being closely monitored for other side effects.
In Germany, around 1.1 million people have been vaccinated since the BioNTech agent was approved by January 13, 2021. The only serious side effects that have occurred to date are very rare cases of allergy in humans. Most were already known to suffer from severe allergic reactions. No other serious side effects were reported. There are also no known long-term complications caused by the BioNTech vaccine. There is not enough data on allergic reactions for the Moderna vaccine.
What other vaccines against Covid-19 are currently being developed?
The vaccine from AstraZeneca and the University of Oxford is the next hot candidate: it is already being used in Great Britain and has applied for approval in the EU. CureVac from Germany is currently in phase 3 of the clinical studies. China, Russia and India have developed their own vaccines against Covid-19, but these are not approved in the EU.
Looking ahead, there are over 100 other vaccine candidates in various stages of development and clinical testing worldwide.
Who should not be vaccinated?
Children and adolescents under the age of 16 are not initially vaccinated. There is currently very little data on the effectiveness or safety of vaccination in adolescents and no data on safety in young children. However, vaccine studies with children are already being planned.
Pregnant women are not routinely vaccinated. This is because there were no pregnant women among the participants in the clinical study. Thus, there is no guarantee that the vaccine will be safe for this group. However, there is currently no evidence that the vaccine is unsafe for pregnant women. Pregnant women who are at high risk of developing a severe course of Covid-19 may be offered the vaccination after a thorough examination. The guidelines for routine vaccination of low-risk pregnant women may evolve and change in the future.
If you have a high fever on the day of the vaccination, you will not be vaccinated.
How many people need to be vaccinated for the pandemic to end?
According to mathematical models, 70% of the population must be immune to the coronavirus. Then the transmissions would be restricted enough for us to stop the pandemic. Research on immunity to Covid-19 is still ongoing. There is no data yet on how long the vaccine protection lasts. In addition, we do not yet know for sure whether vaccinated people can also transmit the virus. One thing is certain: the more people who get vaccinated, the better.
