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After a year that resulted in more than 1.7 million deaths and multiple lockdowns, many people are welcoming the news that COVID-19 vaccines are beginning to be administered to the public. Widespread 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 the safety of vaccines in general, while others are suspicious of 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.
What COVID-19 vaccines have been approved and what does that mean?
Vaccines are not allowed, along with all other drugs, until a country “approves” them. This approval process is carried out in each country or group of countries by an independent agency.
In the US this is done by the FDA (Food and Drug Administration), in the UK by the MHRA (Medicines and Health Products Regulatory Agency) and in the European Union by the EMA (European Medicines Agency).
For anything to be approved by these agencies, it must show that it is 1) safe and 2) does what it is supposed to do.
There are numerous COVID-19 vaccines that are currently in research and development. Although some of these are already being used in Russia and China, currently only two vaccines are approved for use in the US and Canada.
One is a joint effort by Pfizer and BioNTech called ‘BNT162b2’ and the other is manufactured by Moderna and is called ‘mRNA-1273’. BNT162b2 has been approved in 9 countries around the world, including the UK, and is also licensed by the EMA.
How is a vaccine approved?
In order for Pfizer and Moderna vaccines to be approved by the agencies listed above, they must have been shown to be safe. The safety data that is analyzed during the approval process covers every step of the vaccine journey, from initial experiments in the laboratory to the manufacturing process.
An important part of this data is clinical trials. All drugs, including vaccines, go through three stages of clinical trials:
- Stage I ~ test the vaccine on a small group of volunteers (20-80) to verify its safety and find the correct dose
- Stage II: Find out if the vaccine really works by dividing 100-300 volunteers into two groups and giving one group the vaccine and the other group a placebo.
- Stage III ~ divides thousands of volunteers into a vaccine group and a placebo group at random. Do not tell volunteers or doctors who is in which group (this is called doing the “double blind” trial) and check to see if the vaccine is working and if there are any side effects.
If a trial is unsuccessful, for example, the results show that the vaccine does not actually prevent disease or cause adverse side effects, the trial is stopped and the vaccine is not approved.
Even once the vaccine has been approved, it goes 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, 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 they were given it to thousands. Sometimes this also occurs in response to flu shots, and healthcare workers are ready to handle such reactions when they administer the vaccine.
Both people have made a full recovery, but gathering information on this is helpful – for example, the UK has now issued precautionary advice for people who have 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 anywhere in the world world will provoke a quick review and changes if warranted. “
What security data is there?
Both the Pfizer and Moderna vaccines have undergone all three clinical trials and no serious side effects have been found from their vaccines.
For the Pfizer vaccine, 195 people were recruited in the US-based phase I trial and 456 were included in the Germany-based phase II trial. In both trials, no one who got the vaccine had serious side effects. Pfizer’s phase III trial has been published in a peer-reviewed journal and included more than 40,000 volunteers at 152 sites around the world.
In this trial, the volunteers were divided into two groups. One group received two placebo injections 21 days apart, and one group received the actual vaccine injections. This means that, in the end, 18,566 people received the 2 full doses of the vaccine.
For 14 weeks after the second puncture, the 18,366 volunteers were screened for side effects, both through surveys and by taking blood samples. After the second puncture, only 0.8 percent of them had a fever. The most common symptoms were pain at the injection site, and sometimes muscle and headaches.
Professor Rick Kennedy of the Mayo Clinic explains that “the vast majority of observed side effects were expected and are a direct result of the immune response to the vaccine. The side effects are similar to those seen with most of the other licensed vaccines and the mineral occurs at similar rates and with similar severity levels (mainly mild and moderate). ” No one in the study had a serious reaction to the vaccine.
One important factor is that this phase III study included people of diverse backgrounds: 49 percent were female and 37 percent were black, African American, or Hispanic. In addition to this, the study included people who may be at a higher risk level: 35 percent of the participants were obese, 21 percent had at least one coexisting condition, and the average age of the volunteers was 52.
The Moderna vaccine similarly included 120 people in its phase I trial and 600 people in its phase II trial. Although not all of the Phase III data is available to the public yet (approved agencies have access), it included 30,000 people from various demographics and has seen no serious side effects.
All of the above information is freely available for anyone to read. In addition to this, 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 typically over 10,000 pages long and is carefully scrutinized by the FDA, MHRA, and EMA.
What do COVID vaccines contain?
Both Moderna and Pfizer vaccines are RNA vaccines. RNA is the information within the SARS-CoV-2 virus that encodes the entire machinery of the virus.
Traditional vaccines use a killed or modified version of the virus to cause the body to create an immune response, so it learns to recognize this virus and thus becomes immune to it. Instead, RNA vaccines use a modified version of the RNA from the SARS-CoV-2 virus.
When RNA enters your cells, your cells produce their own virus fragments, which then teach your 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 for Immunology explains: “At any given time, a human cell has more than 5,000 different RNA messages, and they are all temporary messages, like sticky notes that cells tear up minutes or hours after being read. “
The RNA in the vaccine is broken down the day after the injection. Importantly, vaccines only contain a small section of RNA, “the RNA message is for a single coronavirus protein. It takes 25 different coronavirus proteins to produce a coronavirus, so you don’t have to worry about the RNA produce a virus. “
RNA is packed into tiny balls of fat called lipid nanoparticles. These lipids are broken down and eliminated by your cells. The other ingredients are water and some salts and sugars to keep these particles stable.
This technology of RNA release by lipid nanoparticles has not been used before for vaccines. However, drugs that use lipid nanoparticles (called ‘nanomedicines’) have been used since the 1990s, and more than 20 different ones have been approved by the FDA or EMA to date. Some of these drugs are based on RNA, similar to RNA vaccines. They are generally used for gene and cancer therapies.
How come vaccines were made so fast?
Vaccines generally take years to develop and produce. The COVID-19 vaccines took less than a year. This is for several reasons, three of which are explained by Dr. Robert Carnahan of Vanderbilt University Medical Center:
“One, all of the vaccines … were manufactured ‘at risk.’ This means they were being produced before clinical trials were completed. This would never happen in a normal situation. Many of these costs were funded by various government organizations around Therefore, the instant the emergency approval was obtained, the distribution could begin.
Second, vaccine developers were rapidly analyzing data as it appeared and communicating it in real time to various regulatory agencies. Often there are gaps of months to years between the various phases of clinical trials solely due to these activities.
Third, recruitment for clinical trials is often a time consuming 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, it was quick to find enough and appropriate volunteers. “
Importantly, the speed did not affect the clinical trials and safety aspects of the process: “The size, thoroughness, and complexity of the clinical trials conducted for current COVID-19 vaccines were no different than traditional clinical trials. These they are as safe as vaccines and the interventions were developed in much slower time frames. ” – says Dr. Carnahan.
A balance of risk
Nothing in medicine is 100 percent safe: You don’t take medicine for a disease you don’t have or a vaccine against a disease that doesn’t exist.
Dr. William Hausdorff of PATH, a nonprofit global public health organization, explains that “all discussions about the ‘safety’ of vaccines (or drugs in general) must begin with discussions of how serious and common it is. the condition you are trying to prevent or treat. If the condition is very mild, even trivial side effects may not be worth it. If the condition is very severe, people will accept much larger potential side effects. “
Every medical intervention is a balance between risk and benefit. Both the Pfizer and Moderna vaccines have shown greater than 90 percent efficacy in protecting people from 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 vaccines.
The Takeaway
All 14 experts agreed with the scientific consensus that COVID vaccines that have been approved by the proper 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 get vaccinated 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 association with the independent fact-checking platform Metafact.io. Sign up for their weekly newsletter here.
