The Guardian
Side effects of the Covid vaccine: what to know and why not to worry
Side effects have been reported for all three vaccines approved for emergency use in the U.S., but most are mild and short-lived. As more people become eligible to receive a coronavirus vaccine, many are asking what side effects to expect and whether there are differences between the side effects of the vaccines. The short answer to both questions is yes – the details are below – although any discomfort is less compared to hiring Covid-19. We use clinical trial data collected by the United States Food and Drug Administration (FDA) to explore the types of side effects most commonly associated with the three vaccines currently authorized for emergency use in the United States. These vaccines were developed by Pfizer and BioNTech, Moderna and the National Institute of Allergy and Infectious Diseases (Niaid) and, more recently, by Johnson & Johnson. What are the common side effects? For all vaccines, the most common side effects include: Pain where the vaccine is injected. Fatigue. Headache and muscle pain. Less common side effects can also include nausea, chills and fever. The vast majority of symptoms cause discomfort, but not a complete break from your daily habits. Are Covid-19 vaccines safe? yea. Its safety is tested in large trials with tens of thousands of people, so the FDA and the Centers for Disease Control and Prevention (CDC) continue to monitor vaccine safety data, including side effects, after vaccines are authorized. They are sometimes called phase IV studies. This monitoring goes hand in hand with the reports through various vaccine safety records. These ongoing studies may help to identify the rarest side effects and identify people who may have special sensitivities to the vaccine, as a potential for an allergic reaction. One of the key numbers included in the charts below is the rate of people who experienced side effects after receiving a “placebo” or injection of saline instead of the vaccine. The people involved in the trials did not know whether or not they received the vaccine. This helps researchers understand the background rate of these side effects in the population. Side effects of the Moderna vaccine Formally called mRNA-1273, this vaccine was developed by Moderna in partnership with Niaid, but most people know it simply as the Moderna vaccine, which is a two-dose regimen with an interval of 28 days. A clinical trial involving more than 30,000 participants at 99 sites in the USA found that the vaccine was safe and effective, and protected people against Covid 94.1% of the time. Among the trial participants, 15,168 people received the vaccine and the rest received a placebo. Side effects of dose 1 of Moderna We used the results of vaccine tests to describe the likelihood of people aged between 18 and 64 years old having a certain side effect within one week after the dose of the vaccine. On average, these symptoms disappear in three days, and usually less. Standard side effects of dose 2 of Moderna An important feature of the two-dose regimen is that people are more likely to experience side effects after the second dose. side effects of the standard Pfizer vaccine A vaccine developed by Pfizer under the pharmaceutical name BNT162B2 uses mRNA technology, much like the Moderna vaccine. The test used 152 sites worldwide. Although the majority (130) were in the United States, the test sites were also located in Brazil, Argentina and South Africa. More than 43,000 people were involved in the trial. The vaccine was considered 95% effective in preventing Covid-19. The Pfizer vaccine uses a two-dose regimen with an interval of 21 days. Side effects of Pfizer dose one Unlike Moderna, Pfizer studied side effects in two different age groups: people between 16 and 55 years old and people over 55 years old. group is displayed here. Standard side effects of Pfizer dose two Like the Modern vaccine, some side effects were more common after the second dose. standard Johnson & Johnson side effects The most recent vaccine authorized in the United States is from Johnson & Johnson’s subsidiary, Janssen. The Johnson & Johnson test included more than 40,000 people in 19 geographic regions. It is important to note that this included South Africa, where the vaccine was found to be somewhat less effective against variant B1351. The FDA found that this vaccine is more than 66% effective in preventing moderate to severe Covid-19. Although this rate of effectiveness is lower than the two vaccines discussed earlier, it still offers almost perfect protection against hospitalization and death and offers advantages in combating the pandemic. Johnson & Johnson side effects The Johnson & Johnson vaccine requires only one dose, usually has a lower rate of side effects. pattern What causes side effects? Side effects are a sign that the vaccine is inducing your body to mount an immune response. They can be uncomfortable, but they can also be a sign that the vaccine is working as expected. Side effects are caused by the release of chemicals into the body that signal to the immune system that it is time to mount a response. These naturally occurring chemicals are called cytokines and chemokines. Although there is no direct correlation between side effects and an immune response, side effects are an expected part of the process. “What we look for as vaccinologists is the Goldilocks response,” said Dr. Greg Poland, editor-in-chief of the medical journal Vaccine and head of the Vaccine Research Group at the Mayo Clinic. Poland also provides consultancy to leading vaccine manufacturers. “We don’t want too little” immune response, “we don’t want too much, we just want enough”, said Poland. The balance that Poland is describing is sometimes referred to as between “immunogenicity” and “reactogenicity”, or the propensity to solicit an immune response versus the tolerability of side effects. Why should I trust this data? In vaccine science, these generally mild side effects are described as “adverse events”. In studies of the Covid-19 vaccine, researchers collected information on everything from hip fractures to heart attacks to monitor the safety of these vaccines. “We have a very, very robust system in the United States,” to track adverse vaccine events, Poland said. “It is how we were able to identify an anaphylaxis risk in specific types of people, occurring at a rate of 2.4-4.5 per million, something that you could never have done in this timely manner in the past.” It is important to note that the vast majority of these side effects are not related to vaccines, but are documented to ensure that there is no standard and to verify the safety of one of the only medical interventions administered to healthy people. The FDA then produces its own analysis of vaccine tests, and the data is presented to an independent panel of experts, who review them and make recommendations on vaccine authorization based on the results. The FDA analyzes submitted to the committee are public and can be seen here, as well as the meetings of this panel of experts.