After a year of more than 1.7 million deaths and multiple blockades, many people welcome the news that COVID-19 vaccines are beginning to be made available to the public. Widespread vaccination may mean that life can return to pre-pandemic normalcy, although this scenario depends on people’s willingness to receive the blow.
Some people are concerned about the safety of vaccines in general, while others suspect the novelty and fast investment time of COVID vaccines in particular. We asked 14 experts in immunology, biostatistics, and vaccinology whether COVID-19 vaccines are safe.
What COVID-19 vaccines have been approved and what does this mean?
Vaccines, along with other medicines, cannot be used until a country approves them. This approval process is carried out in each country or group of countries by an independent agency.
In the United States it is the FDA (Food and Drug Administration), in the United Kingdom the MHRA (Medicines and Healthcare Products Regulatory Agency) and in the European Union the EMA (European Medicines Agency).
In order for any agency to be approved by these agencies, it must demonstrate that it is 1) safe and 2) does what it is meant to do.
There are currently numerous vaccines against COVID-19 in the research and development phase. Although some of these are already used in Russia and China, there are currently only two vaccines approved for use in the US and Canada.
One is a joint effort of Pfizer and BioNTech called ‘BNT162b2’ and one is manufactured by Modern and called ‘mRNA-1273’. BNT162b2 has been approved in 9 countries around the world, including the UK, and is also authorized by the EMA.
How is a vaccine approved?
In order for Pfizer and Moderna vaccines to be approved by the aforementioned agencies, they must have been shown to be safe. The safety data examined during the approval process covers all steps of the vaccine journey, from the initial laboratory experiments to the manufacturing process.
An important part of this data is clinical trials. All drugs, including vaccines, go through three stages of clinical trials:
- Phase I: Test the vaccine in a small group of volunteers (20-80) to check for safety and find the right dose
- Stage II: Find out if the vaccine really works by dividing 100 to 300 volunteers into two groups and giving one group the vaccine and the other group a placebo.
- Stage III ~ randomly divides thousands of volunteers into a vaccine group and a placebo group. Do not tell volunteers or doctors who belongs to which group (this is said to be a “double-blind” trial) and check if the vaccine works and if there are any side effects.
If a trial is unsuccessful, for example, the results show that the vaccine is not actually preventing the disease or that it is causing adverse side effects, the trial is stopped and the vaccine is not approved.
Even once the vaccine is approved, it goes into phase IV, where it continues to be monitored and information about the adverse effects is collected. This is important in determining if there are very rare effects, for example, with a probability of 1 in 100,000,000.
For example, two people in the UK had an allergic reaction to the Pfizer vaccine after giving it to thousands of people. Sometimes this also happens in response to flu vaccines, and health care workers are prepared to deal with these reactions when they get the sting.
Both people have fully recovered, but gathering information on this is useful, for example, the UK has now issued precautionary advice to people with severe allergies.
Dr. Olivera Finn, of the University of Pittsburgh, explains that “all new vaccines continue to be monitored once they begin to be widely distributed. We are now well connected to the whole world, so a single problem with the vaccine in any part of the world will cause a rapid examination, and changes if justified “.
What security data is there?
Both Pfizer and Moderna vaccines have undergone all three clinical trials and have found no serious side effects from their vaccines.
For the Pfizer vaccine, 195 people were recruited for the phase I test based in the United States and 456 for the phase II test based in Germany. In both trials, no one who received the vaccine had serious side effects. Pfizer’s Phase III trial has been published in an expert-reviewed journal and has included more than 40,000 volunteers in 152 locations around the world.
In this trial, the volunteers were divided into two groups. One group was given two placebo shots 21 days apart and one group was given the actual vaccine shots. This means that in the end 18,566 people received the two full doses of the vaccine.
For 14 weeks after the second stroke, the 18,366 volunteers for side effects were assessed, both by surveys and by taking blood samples. After the second blow, only 0.8 percent of them had a fever. The most common symptoms were pain at the injection site and sometimes sore muscles and headaches.
Professor Rick Kennedy of the Mayo Clinic explains that “the vast majority of side effects seen were expected and are the direct result of the immune response to the vaccine. The side effects are similar to what has been seen with most others. licensed vaccines and ore produced at similar rates and with similar severity levels (mostly mild and moderate) “. No one in the study had a severe reaction to the vaccine.
An important factor is that this Phase III study included people from diverse backgrounds: 49% were women and 37% were black, African American, or Hispanic. In addition, the study included people who may have a higher level of risk: 35% of participants were obese, 21% had at least one coexisting condition, and the mean age of the volunteers was 52 years.
The Modern vaccine similarly included 120 people in its phase I trial and 600 people in its phase II trial. Although not all Phase III data is yet available to the public (approval agencies have access to), it included 30,000 people from diverse demographics and has not seen any serious side effects.
All of the above information is available for free so everyone can read it. In addition, the regulatory agencies that approved these two vaccines had access to much more data covering not only clinical trials, but also laboratory and animal studies. This information is usually over 10,000 pages long and is carefully examined by the FDA, MHRA and EMA.
What about COVID vaccines?
Both Moderna and Pfizer vaccines are RNA vaccines. RNA is the information in the SARS-CoV-2 virus that encodes all the machinery of the virus.
Traditional vaccines use a dead or modified version of the virus to cause the body to create an immune response, so it learns to recognize that virus and therefore becomes immune to it. RNA vaccines use a modified version of SARS-CoV-2 virus RNA.
When RNA enters cells, the cells make their own virus fragments, which they then teach the body to become immune like any other vaccine. RNA itself is not harmful, in fact your cells make and use RNA all the time.
As Professor Crotty of the La Jolle Institute of Immunology explains: “At any given time, a human cell has more than 5,000 different RNA messages, and they are all temporary messages, like post-it notes that are ripped by the cells within minutes or hours of being read. “
Vaccine RNA is broken down one day after injection. It is important to note that vaccines contain only a small section of RNA, “the message of RNA is for a single coronavirus protein. It takes 25 different coronavirus proteins to make a coronavirus, so there is no no concern for RNA to produce a virus “.
RNA is packaged in small fat balls called lipid nanoparticles. These lipids decompose and are eliminated by the cells. The other ingredients are water and some salts and sugars to keep these particles stable.
This RNA supply technology for lipid nanoparticles had not been used before for vaccines. However, drugs that use lipid nanoparticles (called “nanomedicines”) have been used since the 1990s, and to date, more than 20 different drugs have been approved by the FDA or EMA. Some of these drugs are based on RNA, similar to RNA vaccines. They are commonly used for cancer and gene therapies.
How were the vaccines developed so quickly?
Vaccines usually take years to develop and produce. COVID-19 vaccines took less than a year. This is due to several reasons, three of which are explained by Dr. Robert Carnahan of Vanderbilt University Medical Center:
“One, all vaccines … were made ‘at risk.’ That means they were produced even before the clinical trials were completed. This would never happen in a normal situation. Many of these costs were supported by various government organizations Therefore, by the time emergency approval was obtained, distribution could begin.
Second, vaccine developers quickly analyzed the data as it emerged and communicated it in real time to various regulatory agencies. There are often differences from months to years between the various phases of clinical trials due only to these activities.
Third, recruitment for clinical trials is often a slow and laborious process. There must be people at risk for the disease in many different demographic and health categories. Due to the immense scope of the pandemic, finding enough and suitable volunteers was quick. “
It is important to note that the speed did not affect the clinical trials and the safety aspects of the process: “The size, completeness and complexity of the clinical trials performed for current COVID-19 vaccines were no different from traditional clinical trials. They are so safe. how vaccines and interventions developed in much slower terms. ” – says Dr. Carnahan.
A risk balance
Nothing in medicine is 100% safe: don’t take medication for a disease you don’t even have a vaccine for a disease that doesn’t exist.
Dr. William Hausdorff of PATH, a global nonprofit public health organization, explains that “all discussions about” safety “for vaccines (or drugs in general) should start with discussions about the severity and frequency of disease that you try to prevent or treat If the condition is much less, even trivial side effects are not worth it. If the condition is very serious, people will accept much bigger potential side effects. “
All medical intervention is a balance between risk and benefit. Both the Pfizer and Modern vaccines have been shown to be 90% effective in protecting people against COVID-19 in their Phase III clinical trials. This protection against a virus that has so far caused more than 1.7 million deaths worldwide is also an important consideration when thinking about vaccine safety.
Takeaway food
The 14 experts agreed with the scientific consensus that COVID vaccines that have been approved by appropriate regulatory agencies such as the FDA are as safe as any other vaccine or drug.
Nothing in medicine is risk free and the decision to take a vaccine is personal and depends on a person’s individual circumstances.
Article based on 14 expert answers to this question: are COVID-19 vaccines safe?
This expert response was published in collaboration with the independent fact-checking platform Metafact.io. Subscribe here to their weekly newsletter.