After a year that resulted in more than 1.7 million deaths and several blockages, many people are receiving the news that the COVID-19 vaccines are beginning to be distributed to the public. Generalized vaccination can mean that life can return to pre-pandemic normality; however, this scenario depends on people’s willingness to receive the vaccine.
Some people are concerned about vaccine safety in general, while others suspect the novelty and rapid response time of COVID vaccines in particular. We asked 14 experts in immunology, biostatistics and vaccinology if COVID-19 vaccines are safe.
Which COVID-19 vaccines have been approved and what does this mean?
Vaccines, along with all other drugs, 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 USA, this is done by the FDA (Food and Drug Administration), in the United Kingdom by MHRA (Regulatory Agency for Medicines and Health Products) and in the European Union by EMA (European Medicines Agency).
For anything to be approved by these agencies, it must show that 1) it is safe and 2) it does what it must do.
There are several COVID-19 vaccines currently in research and development. Although some of them are already being used in Russia and China, only two vaccines are currently approved for use in the United States and Canada.
One is a joint effort by Pfizer and BioNTech called ‘BNT162b2’ and the other is manufactured by Moderna and called ‘mRNA-1273’. BNT162b2 has been approved in 9 countries worldwide, including the United Kingdom, and is also authorized by the EMA.
How is a vaccine approved?
For Pfizer and Moderna vaccines to be approved by the agencies mentioned above, they must have been shown to be safe. The safety data examined during the approval process covers all stages of the vaccine journey, from initial laboratory experiments to the manufacturing process.
An important part of these data are clinical trials. All drugs, including vaccines, undergo three stages of clinical trials:
- Stage I ~ test the vaccine on a small group of volunteers (20-80) to see if it is safe and find the right dose
- Stage II – find out if the vaccine really works by dividing 100-300 volunteers into two groups and administering the vaccine to one group and to the other group a placebo.
- Stage III ~ randomly divide thousands of volunteers into a vaccine group and a placebo group. Do not tell volunteers or doctors who is in which group (this is called doing the ‘double-blind’ test) and check if the vaccine is working and if there are any side effects.
If a trial is not successful, for example, the results show that the vaccine is not actually preventing the disease or causing adverse side effects, the trial is stopped and the vaccine is not approved.
Even after being approved, the vaccine moves to Phase IV, where it continues to be monitored and information on adverse effects is collected. This is important to establish if there are very rare effects, for example, a 1 in 100 million chance.
For example, two people in the UK had an allergic reaction to the Pfizer vaccine after it was applied to thousands. This also sometimes happens in response to flu vaccines, and healthcare professionals are ready to deal with such reactions when they administer the vaccine.
Both people have fully recovered, but collecting information about this is useful, for example, the UK has already issued precautionary advice for people who have severe allergies.
Dr. Olivera Finn, from the University of Pittsburgh, explains that “All new vaccines continue to be monitored once they start to be widely distributed. We are now well connected with the whole world, so a single vaccine problem anywhere the world will require a quick review and changes, if guaranteed. “
What safety data is there?
Both the 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 in the Phase I study based in the USA and 456 were included in the Phase II study in Germany. In both trials, no one who received the vaccine had serious side effects. Pfizer’s Phase III trial was published in a peer-reviewed journal and included more than 40,000 volunteers at 152 locations worldwide.
In this trial, the volunteers were divided into two groups. One group received two placebo vaccines 21 days apart, and one group received the actual vaccines. This means that in the end 18,566 people received the full 2 doses of the vaccine.
During 14 weeks after the second injection, all 18,366 volunteers were evaluated for side effects, both by research and by collecting blood samples. After the second injection, only 0.8 percent had a fever. The most common symptoms were pain at the injection site and sometimes sore muscles and headaches.
Professor Rick Kennedy, from the Mayo Clinic, explains that “the vast majority of side effects seen were expected and are a direct result of the immunological response to the vaccine. Side effects are similar to those seen with most other licensed vaccines and ore occurring at rates similar and with similar levels of severity (mostly mild and moderate). “No one in the study had a serious reaction to the vaccine.
An important factor is that this Phase III study included people from diverse backgrounds: 49 percent were women and 37 percent were black, African American or Hispanic. In addition, the study included people who may be at a higher risk level: 35 percent of participants were obese, 21 percent had at least one coexisting condition, and the average age of volunteers was 52.
The Modern vaccine also included 120 people in its Phase I trial and 600 people in its Phase II trial. Although not all Phase III data is available to the public yet (approving agencies have access), they included 30,000 people from diverse demographic groups and did not see any serious side effects.
All of the above information is freely available for anyone to read. 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 generally over 10,000 pages and is carefully examined by the FDA, MHRA and EMA.
What’s in the COVID vaccines?
The Moderna and Pfizer vaccines are RNA vaccines. RNA is the information within the SARS-CoV-2 virus that encodes all of the virus’s machinery.
Traditional vaccines use a dead or modified version of the virus to cause the body to create an immune response, so that it learns to recognize this virus and therefore becomes immune to it. RNA vaccines use a modified version of the SARS-CoV-2 virus RNA.
When RNA enters your cells, they produce their own virus fragments, which then teach your body to become immune like any other vaccine. RNA alone is not harmful; in fact, your cells produce and use RNA all the time.
As Professor Crotty of the La Jolle Institute of Immunology explains, “At any one time, a human cell has more than 5,000 different RNA messages and they are all temporary messages, like post-its that are torn by the cells minutes or hours after they are read.”
The vaccine’s RNA is broken down one day after the injection. Importantly, vaccines contain only a small section of RNA, “the RNA message is for a single coronavirus protein. It takes 25 different proteins from the coronavirus to make a coronavirus, so there is no concern about the RNA that is creating a virus”.
The RNA is packed in small balls of fats called lipid nanoparticles. These lipids are broken down and eliminated by the cells. The other ingredients are water and some salts and sugars to keep these particles stable.
This technology of delivering RNAs by lipid nanoparticles has not been used for vaccines before. However, drugs that use lipid nanoparticles (called ‘nanomedicines’) have been in use since the 1990s and, to date, more than 20 different ones have been approved by the FDA or EMA. Some of these drugs are based on RNA, similar to RNA vaccines. They are generally used for cancer and gene therapies.
Why were vaccines made so quickly?
Vaccines typically take years to develop and produce. COVID-19 vaccines lasted less than a year. This is due to a number of reasons, three of which are explained by Dr. Robert Carnahan of Vanderbilt University Medical Center:
“First, all vaccines … were manufactured ‘at risk’. That means they were being produced before clinical trials were even completed. This would never happen in a normal situation. Many of these costs were borne by various government organizations around So as soon as emergency approval was obtained, distribution could begin.
Second, vaccine developers were quickly analyzing the data as it emerged and communicating it in real time to various regulatory agencies. Often, there are intervals of months to years between the various phases of clinical trials due to these activities alone.
Third, recruiting for clinical trials is often a slow and laborious process. There must be people “at risk” of contracting the disease in many different demographic and health categories. Due to the immense scope of the pandemic, finding sufficient and appropriate volunteers was quick. “
It is important to note that speed did not affect clinical trials and the safety aspects of the process: “The size, effectiveness and complexity of clinical trials conducted for current COVID-19 vaccines were no different from traditional clinical trials. safe as vaccines and interventions developed in much slower terms. “- says Dr. Carnahan.
A balance of risk
Nothing in medicine is 100% safe – you don’t take medication for a disease you don’t have or a vaccine against a disease that doesn’t exist.
Dr. William Hausdorff of PATH, a global non-profit public health organization, explains that “all discussions about ‘safety’ for vaccines (or medicines in general) should start with discussions about the severity and frequency of the disease you are experiencing. trying to prevent or treat. If the condition is too small, even the trivial side effects may not be worth it. If the condition is too serious, people will accept much greater potential side effects. “
Each medical intervention is a balance between risk and benefit. Both the Pfizer and Moderna vaccines showed> 90 percent effectiveness 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 the safety of the vaccine.
The Takeaway
All 14 experts agreed with the scientific consensus that COVID vaccines that have been approved by the appropriate regulatory agencies, such as the FDA, are as safe as any other vaccine or medication.
Nothing in medicine is risk-free and the decision to get the vaccine is personal and depends on the individual circumstances of each person.
Article based on 14 expert responses to this question: Are COVID-19 vaccines safe?
This expert response was published in partnership with the independent fact verification platform Metafact.io. Subscribe to the weekly newsletter here.