The fight against the coronavirus pandemic is entering the critical phase: Vaccinations against the Covid-19 have begun in many countries around the world and each and every day we see more and more Covid vaccine getting approved.
It was the quickest vaccine development of all time: Less than a year after the genetic code of Sars-CoV-2 was deciphered, three Covid vaccine candidates are approved worldwide and one is about to get approval. Two of them, BNT162 and mRNA-1273, are so-called gene-based vaccines, in other words, these are vaccines that use genetically engineered DNA. The process is still new and has never been used to produce a mass-produced vaccine.
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A Look at the Covid Vaccine
Initial reports of Phase 3 test results are now available for four Corona vaccines. Do the gene-based candidates differ from the vector-based candidates? For the elderly, who are most at risk from Corona, which agent works best? In this article, we will take a look at different vaccines which are being used today in different countries and compare them. Then we want to answer some of the questions you might have got regarding Covid vaccine.
BNT162 Covid Vaccine From PFIZER/BIONTECH
It’s the big breakthrough for Mainz-based biotech company BioNTech and its partner, U.S. pharmaceutical company Pfizer. On November 18, the duo shared results from Phase 3 trials of their Covid vaccine candidate BNT162. Around 43,000 people took part in the trials, half of whom received the vaccine.
BNT162 is a gene-based Covid vaccine. It consists of a small piece of genetic information in the form of messenger RNA (mRNA) that is encapsulated in nanoparticles of fat and inserted into muscle cells. There, the RNA directs the construction of the corona spike protein, which is subsequently shown by the vaccinated cells and recognized by the immune system as hostile. Antibodies and T cells are formed, which then take effect when a real infection with Sars-CoV-2 occurs.
Scientists estimate that the risk of the RNA being permanently integrated into the genetic information in the cell nucleus is extremely low. But even if it were: To actually change the human genome, this process would have to take place at least in all stem cells of the body. However, the very fragile RNA, which is injected into outer muscles, cannot reach these cells.
According to the announcement, a total of 170 participants became infected with Covid-19 during the test phase, 162 of whom had received the placebo and 8 the vaccine. Of the 8 participants who contracted Covid-19 despite vaccination, only one suffered a severe course of infection; in the placebo group, there were a total of 9 severe cases. Thus, the effectiveness of all participants is approximately 95 percent. In relation to the older than 65-year-old participants, the efficiency was still 94 percent, the companies announced.
Pfizer/BioNTech Covid Vaccine Side Effects
The most common side effect reported was pain at the injection point, however more severe side effects reported include:
- Fatigue after the second vaccination
- Headache: 52 percent in under 55 participants and 39 percent in older than 55
- Exhaustion: 59 percent in under 55 participants and 51 percent in older than 55.
- 38 degrees fever: 16 percent in under 55 participants and 11 percent in older than 55
- Over 38.9 degrees fever: 0.8 percent in under 55 participants and 0.8 percent in older than 55
Pros and Cons of RNA Covid Vaccines
The biggest advantage of RNA vaccines, in theory, is the simpler manufacturing process. While classical vaccines based on altered or killed viruses require the production of these viruses in cell crops or chicken eggs, RNA can be synthesized relatively easily on a mass scale. However, Pfizer’s announcement that the company will only be able to deliver 50 million doses of Covid vaccine in 2020 instead of 100 million as planned shows that problems can arise.
In theory, the vaccine can also be modified relatively easily if the virus mutates.
The biggest downside of RNA vaccines is the instability of the RNA. Transporting it to target cells is one major challenge, the other is storing the vaccine doses: BNT162 must be kept refrigerated at minus 70 degrees or the RNA will break down.
Another disadvantage is the novelty of the procedure: Because there is no experience with RNA vaccines yet, side effects can theoretically occur at later times that are not known yet.
MRNA-1273 Covid Vaccine From MODERNA
U.S. pharmaceutical company Moderna is also relying on a gene-based vaccine for its mRNA-1273 vaccine candidate, which is very similar in principle to the one from BioNTech/Pfizer. It performed very well in Phase 3 clinical trials, according to a Nov. 30 press release.
Among the 30,000 participants, one half received two doses of the vaccine and the other half received two doses of placebo, a total of 196 people contracted Covid-19, and only 11 of those had received the Covid vaccine and still contracted the disease. However, none of this group had a severe case. In the placebo group, on the other hand, 30 people fell seriously ill with corona. In other words, the efficiency of the vaccine was 94.1 percent.
Moderna Covid Vaccine Side Effects
Side effects were not quantified in the press release. The most common side effects were pain at the injection point, fatigue, joint pain, limb pain, and headache. Most of them occurred after the second injection.
However, the interim report from an independent monitoring panel shows that some side effects, such as fatigue, were quite common, occurring in 9.7 percent of those vaccinated with mRNA-1273.
There are also reports that the side effects can be quite severe. A researcher from the renowned Massachusetts Institute of Technology (MIT), among others, reports in Science on his participation in the clinical tests. According to the report, he got a severe vaccination fever the night after the second dose, with temperatures of 38.9 degrees. The symptoms subsided after about 12 hours.
However, the fact that the side effects are greater after the second dose than after the first is a good sign, says immunologist Drew Weissmann in Science magazine. This shows that the immune system has been built up after the first dose and comes into full operation after the second.
AZD1222 FROM ASTRAZENECA AND THE UNIVERSITY OF OXFORD
The team of researchers from the British University of Oxford and the Swedish-British pharmaceutical company AstraZeneca is relying on the proven principle of a so-called vector-based vaccine for the development of their Covid vaccine. The genetic blueprint for Corona’s spike protein is incorporated into a modified cold virus. Specifically, AZD1222 is an adenovirus from chimpanzee ChAdOx1.
If the vaccine candidate proves effective and the risk of side effects is manageable, AZD1222 would be much easier to distribute because it would not require extensive refrigeration. The vaccine could be stored and transported at refrigerator temperatures, which would make it suitable for world regions with poorly developed infrastructure and roads. AstraZeneca projected producing up to three billion doses in 2021.
But there are problems with the candidate’s development. In the summer, clinical trials had to be briefly halted after one study participant developed an infection of the spinal cord. However, after closer examination, medical experts concluded that it was not a reaction to the vaccine.
There was greater confusion in November when the University of Oxford and the pharmaceutical company gave different information about preliminary results of phase 3 clinical trials. According to the report, different doses of the Covid vaccine were inadvertently given in trials in the United Kingdom and Brazil, but the results from the trials that were different. In the end, an effectiveness of 70 percent was reported. However, there is now clear criticism of this statement.
In the meantime, the team has published the data from the phase 3 trial in an article in the journal The Lancet. According to the study, the lower dose of vaccine actually seems to have a better effect; it was 90 percent according to the study. Those who received two full doses, on the other hand, were only 62 percent protected. Together, this results in the protection of about 70 percent.
AstraZeneca Covid Vaccine Side Effects
The side effects of the AstraZeneca vaccine are not much different from the side effects of the Biontech vaccine. The following side effects have been reported so far:
- Headache
- Fever
- Weakness
- Dizziness, nausea
- Pain, bruising, warmth, redness and itching at the injection site
- Increased sensitivity to pain
- Muscle pain
- Loss of appetite
Some of the side effects also occurred at a high intensity, so that the subjects had to stay at home for several days. However, the side effects went away after a few days. In principle, these side effects are a positive sign that the immune system is responding to the vaccine.
SPUTNIK V RUSSIAN COVID VACCINE
Russia’s vaccine candidate Sputnik V is also a vector-based Covid vaccine, in this case using two different modified adenoviruses (rAd26-S and rAd5-S). Unlike the RNA vaccines, the information for the spike protein is delivered into the cells via the viruses used for vaccination, rather than directly. Both viruses contain the genetic information for the spike protein of Sars-CoV-2, and two different viruses were used to safely prevent the immune system from intercepting the second-dose vaccine viruses and inadvertently rendering them harmless.
Russia’s Gamaleya Institute, which is behind the development of Sputnik V, also announced positive results from its Phase 3 trials in late November. For example, more than 18,000 trial participants were treated with either a placebo or the vaccine. In this case, however, the placebo group was apparently much smaller.
A total of 39 covid-19 infections occurred among trial participants, eight of which were in the larger vaccinated group.
Sputnik V Covid Vaccine Side Effects
Not been quantified, mainly pain at the injection site but also headache and vaccination fever.
In this section of our article about Covid vaccine, we want to answer some of your questions about the vaccines. Stay tuned.
What side effects can be expected after receiving the Covid vaccine?
As with all vaccinations, side effects may occur. Those to be vaccinated will be fully informed about this beforehand. In early studies, redness at the injection site, headache, fatigue, fever and chills occurred – similar to a flu shot. These typical vaccination reactions indicate that the body is dealing with the foreign substance, this is, therefore, a desired reaction.
So far, there are no indications of serious long-term side effects. These cannot be generally excluded, the Covid vaccine is still too new and the studies are only a few months old. The most serious side effects so far, however, have been joint pain or swelling of the lymph nodes lasting up to a week – in less than a handful of the 40,000 test subjects.
People who already have serious allergy problems could react with allergic reactions. There are isolated reports of this from Great Britain and the USA, where vaccinations with the Biontech-Pfizer vaccine have already started. The fact that two people in Great Britain have reacted strongly to the Corona vaccine does not mean, however, that allergy sufferers to grass or house dust, for example, should not be vaccinated.
When would herd immunity be achieved?
There are different opinions on this. Many experts believe that herd immunity can be achieved if 60 percent of a country’s population is vaccinated – which would be possible by the end of summer 2021 for lots of countries. World Health Organization experts estimate that 60 to 70 percent of the population would need to be vaccinated.
Other experts assume an even higher vaccination coverage rate of up to 85 percent, depending on how infectious the virus is and can become through mutation. Virologist Melanie Brinkmann of the Helmholtz Centre for Infection Research also estimates that an 80 to 85 percent vaccination coverage of the population is needed.
The mutation of the coronavirus first identified in Great Britain is apparently more contagious than the one known so far. Nevertheless, it has no influence on the Covid vaccine’s protective effect.
The immune response that vaccination is supposed to elicit will still be comprehensive. All things considered, this vaccine will still work. That’s true for all the mutations that have emerged so far. Mutations represent commonplace events for viruses. It is not to be expected that the vaccines will lose their effectiveness.
According to the current scientific knowledge, it can be assumed that the virus mutations observed so far have no effect on the efficacy of the COVID-19 vaccines. mRNA vaccine platforms offer the particular advantage that they can be quickly adapted to mutations.
How often do you have to get Covid vaccine?
For the vaccines from Biontech/Pfizer and Moderna, twice – in a period of just under one month. The first vaccination provides basic immunization. After three to four weeks, one must be vaccinated again. Another two to three weeks later, full protection should be established.
What does the Covid vaccine do? Does it make you immune?
The Covid vaccine is intended to prevent severe courses. So far, the Covid vaccine had a quite outstanding effect. The uptake and transmission of viruses are significantly reduced. The vaccine protection is said to last a relatively long time. It is not impossible that vaccinated people can infect others – but the probability of this is not very high. How long a vaccination protects against infection is also still unclear, as no long-term studies are yet available.
The vaccines from Biontech/Pfizer and Moderna use mRNA to get cells to produce the viral protein spike and thus activate the immune system. Biontech’s vaccine is slightly cheaper. In return, the Moderna vaccine is slightly expensive but can be kept at minus 20 degrees in a normal refrigerator-freezer, while the Biontech vaccine must be kept at minus 80 degrees in special containers.
Do mRNA vaccines alter the human genome?
No. There is no danger of mRNA being integrated into the human genome. The genetic material consists of DNA and is located in the cell nucleus. The mRNAs are working copies of the active genes that make the genetic information available for the production of proteins. mRNA is rapidly degraded, so the cell remains flexible. The mRNA from the vaccine integrates into this natural process. It does not enter the cell nucleus but ensures the production of the viral protein spike. That then stimulates the immune system, while the mRNA from the vaccine is degraded.
The RNA is injected and integrates into the muscle cell – but not where the DNA is, rather into the cell plasma. That’s where the genetic code for the spike proteins is, the spike that the coronavirus uses to enter the cell. This is produced there and presented at the cell surface. In response, the body produces antibodies – similar to what happens after an infection.
What distinguishes the three currently main vaccines?
The vaccines from BIONTech-Pfizer and Moderna are so-called mRNA vaccines. They replicate individual proteins in human cells that are typical for the virus. The body reacts to this by building up an immune defense. The most important difference between the two vaccines: Moderna’s vaccine can be stored for up to 30 days in a normal household refrigerator.
Thus, it does not need to be refrigerated to -70 degrees Celsius, like BioNTech-Pfizer’s vaccine. Although the latter can also be stored in the refrigerator after processing, it must then be used within five days.
AstraZeneca’s vaccine is not an mRNA vaccine, but a so-called vector virus vaccine. It uses a harmless cold virus that normally infects chimpanzees as a transport mechanism. Thus, the Covid vaccine transports the surface protein of SARS-CoV-2 to human cells, where it triggers an immune response against the coronavirus. A normal household refrigerator is also sufficient for this vaccine.
Can a different vaccine be used for the second vaccination?
No, the same vaccine should always be used for the first and second vaccination. There is no experience and no tests with different vaccines, so no one should take a risk.
Should I get vaccinated even if I have already been infected with COVID-19?
Anyone who has survived infection with the virus can still be vaccinated and should do so. This is because it is not certain that having survived an infection provides adequate protection against re-infection. There have been rare cases of re-infection.
However, physicians should not vaccinate anyone who is going through a COVID-19 infection, or even the flu or other common feverish cold. In that case, the vaccination should not be given until the patient is well again.
Incidentally, the same applies to people who are in quarantine because they have had contact with someone infected with Corona. They should not be vaccinated until the quarantine is over. If they have already been infected, the vaccination would come too late anyway.
Who should not be vaccinated?
In general, a doctor must first clarify whether there are certain pre-existing conditions that would preclude vaccination. This may be the case in particular with allergy sufferers who are allergic to certain ingredients or have already suffered an anaphylactic shock.
Most allergic persons – such as those suffering from hay fever, animal or food allergies – will, however, be able to be vaccinated. Other severe pre-existing conditions, such as diabetes, obesity, or even a weakened immune system, tend to argue in favor of vaccination because their risk of severe COVID-19 is high.
Can children be vaccinated?
The current Corona vaccines are only approved for teenagers 16 years and older and adults.
What do pregnant women need to be aware of?
Experts consider it unlikely that the mRNA vaccines pose a risk to pregnant women and unborn children, yet animal studies on reproductive toxicity are still ongoing. So it remains a trade-off that should definitely be discussed with a physician: on the other hand, pregnancy is considered a risk factor for severe COVID-19 courses, which can also cause severe harm to the child. Furthermore, expectant mothers should also assess their individual risk of infection – how much do they socialize and how likely is a coronavirus infection for them individually?
Is the vaccination Halal as well?
Of course, religious experts will have to answer that question in the end. But the odds are good: spokespersons for the three major manufacturers: Pfizer, Moderna and AstraZeneca have confirmed that their products do not contain any pork products.
Should vaccinated people continue to wear masks?
None of the Covid vaccines is likely to provide full immunity, which means that vaccinated individuals can still pass on the pathogen, although probably in smaller quantities. It is known from animal studies that although vaccinated monkeys do not become ill when infected with Sars-CoV-2, they do have a live virus in their noses that they can spread. For this reason, vaccinated individuals cannot be exempt from a mask requirement and should not do so, even for their own protection. They should also continue to follow the rules.
Could there still be complications a few years after vaccination?
There can be no real long-term evidence yet, barely four months after the first administration of the vaccine to a larger group of test subjects. The trial participants are to undergo health monitoring for two years. In the past, the rarely documented vaccine damage has usually occurred fairly soon after vaccination, rather than years later. However, it is not true that there is no long-term clinical trial experience with mRNA vaccines, as is often claimed: vaccines of this type have been tested in humans against other infectious diseases for more than five years and have so far been shown to be very well tolerated in these trials.
