At the beginning of December, Britain’s health system became the first to begin vaccinating the population using Pfizer-BioNTech’s messenger RNA coronavirus vaccine.
It was the first time that messenger RNA technology, which had been used in research for about 30 years, was being used to treat the public at large. Since then, roughly 100 million people have been inoculated using mRNA vaccine produced by Pfizer-BioNTech or Moderna. The information now available about possible side effects demonstrates the vaccines are safe – even safer than many experts had anticipated.
Despite the findings, injecting unfamiliar substances into the body, particularly using new technology, has prompted a degree of public concern. Even now, these concerns have spurred on a small group of longtime anti-vaxxers who have been joined by opinion leaders in spreading false information about the COVID-19 pandemic.
The campaign against the vaccine is based on manipulation and misleading information, ranging from exaggerated concern about long-term side effects to distorted medical information and baseless articles published in questionable scientific journals and even false claims that the vaccine can cause Alzheimer’s or mad cow disease.
Taken together, all of this causes harm to a vaccination campaign that, by global consensus, is seen as the key to ending the pandemic. Such misinformation actually increases the number of victims of the virus, despite the high rate of effectiveness of the vaccine.
Such effectiveness has been demonstrated by studies in Israel, which has led the world in the pace of its vaccination campaign, relying almost entirely on the Pfizer vaccine. And this is at a time when the coronavirus has killed nearly 6,000 people in Israel and more than 2.6 million people around the world.
What do we know so far about the side effects from the vaccine, based on their use since the trial stage?
“I didn’t expect any serious problems,” said Prof. Natalia Bilenko, the chief physician for the Asheklon district and the director of the school of public health at the Ben-Gurion University of the Negev. “The vaccine has been administered to tens of millions of people around the world and to nearly five million in Israel. No significant or long-term side effects have been found. The side effects have been minor and disappear after a few days.”
Are the side effects being monitored just to be sure?
Every type of vaccine administered in Israel, not only the coronavirus vaccine, is closely monitored. Any possible side effect, whether short or long-term, is reported directly to the district physician and the Health Ministry and is thoroughly examined to see whether or not it is related to vaccine.
The same is true of the coronavirus vaccine. For this purpose, a safety committee was created comprised of a large number of senior doctors and epidemiologists.
The challenge, Bilenko said, is to understand which of the medical symptoms occurring around the time someone is vaccinated were actually caused by it. When you inoculate millions of people, some of them would be expected to suffer from various medical problems. Therefore, examining the causal relationship between the vaccination and the possible side effects includes looking for the mechanisms through which a vaccine might cause the symptoms that have been observed. The Health Ministry also collects all of the reports of side effects to spot similar symptoms among people who have been vaccinated at various places around the country.
With regard to short-term side effects, the picture is clear: The side effects reported thus far are consistent with the results of Pfizer’s safety trials and with the findings from the past two months in the real world, Belinko said. “Localized pain, weakness, and high fever and flu-like symptoms. All of these effects go away within a few days,” she said.
There are two serious side effects over which there is concern over a link to the vaccine. One is a serious allergic reaction – anaphylactic shock (such as that which some people suffer from a bee sting) – which is apparently caused by an allergy to polyethylene glycol, a stabilizer in the vaccine. The second is temporary paralysis of the facial nerve, which goes away after a few days without treatment, said Dr. Ella Sklan, a virologist at from Tel Aviv University medical school.
An article in the Journal of the American Medical Association two weeks ago reported that, as of January 18, after 17 million Americans had been inoculated with the Pfizer or Moderna vaccine, only 66 had an anaphylactic episode after receiving a dose – meaning fewer than one in 250,000 recipients. All 66 were treated with medication and completely recovered. To this day, there has not been a single documented case in Israel or elsewhere of a death linked to the vaccine.
The second serious side effect, facial paralysis, or Bell’s palsy as it is known, has been very rarely reported – apparently involving a handful of cases per million people vaccinated, Sklan said, and the link to the vaccine has not been clearly demonstrated, since it also occurs among the general population for various reasons without any connection to the vaccine.
“There are a few hypotheses but the mechanism that causes the reaction is not known,” she said. Facial paralysis lasting a few days is not pleasant, but in all of the reported cases so far, it has subsided on its own without leaving a trace of a problem.
The Israel Neurological Association has been doing its own monitoring of side effects from the vaccine through its member physicians. “Up to now, the extent of significant neurological symptoms has been very low in relation to the scope of the population that’s been vaccinated,” the organization reported.
Prof. Gal Ifergan, the director of neurology at Soroka Medical Center in Be’er Sheva, who has coordinated the collection of the data, said the most common neurological symptoms have been impairment of the sense of feel in various body parts and the face, such as pins and needles or a sensation of a body part falling asleep.
Ifergan sought to make it clear that, from the data that he has collected, it can in no way be concluded whether there is a causal connection between the symptoms and the vaccine. His information, he said, simply provides a general picture of possible effects that should be to paid attention to.
The Israeli neurologists have also reported four cases of Guillain-Barre syndrome among vaccine recipients – a rate of one per million. Guillain-Barre syndrome occurs when the immune system begins attacking the peripheral nervous system, causing severe motor difficulties. But Ifergan said cases of Guillain-Barre are reported following every kind of immune disorder and extremely rarely after nearly every type of vaccine – at a reported rate in Israel of one in a million. “If the number of cases was zero, I would suspect someone was playing with the numbers,” Ifergan quipped.
The Health Ministry put it this way: “No phenomena have been seen at a rate greater than what would be expected based on past data and without connection to vaccines.”
What about long-term side effects?
All the experts interviewed by Haaretz agreed that while scientifically, it is impossible to rule out something with 100 percent certainty, the chances of long-term side effects from the COVID vaccine are slim. “Do we know what will happen in another 30 years to someone who has been vaccinated? The answer is no,” said pediatrician Prof. Gideon Rechavi, who is a hematologist and oncologist and RNA researcher at the Sheba Medical Center and Tel Aviv University. Last year he received the Israel Prize in medicine.
Some vaccines can cause significant long-term effects. But they usually begin to surface shortly after the vaccine is administered.
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Dr. Paul Offit was one of the developers of the vaccine against the rotavirus, which has saved the lives of millions. He is also a member of an advisory council that provides guidance to the U.S. Food and Drug Administration.
The council gave its approval on December 10 to Pfizer’s coronavirus vaccine as being safe. In an online seminar, Offit provided examples of the incidence of rare serious side effects from various vaccines, but added that, if there are serious side effects, they occur within six weeks of the vaccination. The yellow fever vaccine causes the actual disease in one in a million recipients. A prior version of the rotavirus vaccine caused intestinal blockages in one to six in 100,000 recipients, while a weakened virus version of the polio vaccine caused polio in one in 2.7 million doses administered on average.
Before the coronavirus vaccination campaign began, Offit said it was impossible to know whether there would be rare side effects. Vaccinating 20,000 people is not the same as vaccinating 20 million and the rare side effects only surface after the vaccine is approved for general use, he said in early December.
Now that a large number of people have been vaccinated, it’s clear that the mRNA coronavirus vaccines don’t cause the rare side effects that are familiar from other vaccines.
The genetic material can’t replicate itself
Messenger RNA has no way to replicate itself in the body, so there is no risk of it happening with the COVID vaccine. The speed at which it breaks up ensures that the only thing it can do is produce a tiny quantity of protein that induces an immune reaction.
“The only remnant that remains in the body after 24 hours on average is the antibodies, not the protein or the mRNA,” Bilenko said.
One reason for the short life of the messenger RNA is that the RNA molecule is very fragile – which is also the reason the vaccine needs to be stored at a very low temperature prior to use. Another reason is that “the body has a lot of enzymes whose job it is to break down mRNA,” said Prof. Amos Panet, a virologist from Hebrew University’s medical school and a member of the committee advising the Israel Institute for Biological Research in its efforts to develop an Israeli coronavirus vaccine.
Is it possible for the vaccine’s RNA to spread around the body and cause damage?
All of the researchers are in agreement that the chances of this are low. Aside from the RNA’s own fragility, the second breakthrough that made the development of the vaccine possible – the tiny fat bubbles (lipids) that surround the vaccine’s RNA and protect it and facilitate its delivery – make the theoretical scenario of vaccine particles circulating throughout the body implausible.
These lipids make the vaccine particles “sticky.” They adhere to the membranes of the cells around them and generate the process by which the RNA is swallowed up by the cells.
The vaccine is injected into the upper arm – an area where there are only tiny blood vessels, and the lipids quickly adhere to the cells in the area – muscle cells, subdermal cells and immune system cells that happen to be there. One cannot say with absolute certainty that the particles are unable to travel great distances in the body, but it’s unlikely, certainly not in high concentrations, Sheba Medical Center’s Rechavi said.
Can the vaccine harm a fetus?
The likelihood of vaccine particles harming a fetus is even lower. Fetuses in the womb are protected from the infiltration of harmful substances by the placenta, which in addition to providing nourishment and oxygen to the fetus also protects it from toxic substances. Even if a vaccine particle would do the totally unexpected and migrate from a woman’s shoulder to the uterus without attaching itself to a single cell en route, it will encounter tissue that is present to prevent the entry of anything likely to harm the fetus. “Nature has created great defenses for the fetus,” said Panet of Hebrew University.
In addition, there is already preliminary data indicating that the vaccine is safe for pregnant women. Sklan explained that, while there were no pregnant women who enrolled in the clinical trials for Pfizer’s vaccine, 18 women became pregnant after receiving the first dose and they experienced no unusual symptoms. Data on the vaccine’s side effects among pregnant women, which were presented this week regarding 1,800 women, showed no difference between their side effects and those of the general population.
There were also no differences found between the usual indices measuring the state of their pregnancies and those of unvaccinated women. The data was presented to the advisory committee of the U.S. Centers for Disease Control and has not yet been published.
Can the vaccine cause an autoimmune disease?
What if the immune system’s response were to cause its own medical problems beyond the known mild side effects? One common concern has been that the inflammatory response would cause a new autoimmune disease.
“So far, there have been no statistical link found between the vaccine and the outbreak of autoimmune diseases,” Sklan said. “At the moment, there is no evidence of this. We will continue to follow this, but there doesn’t appear to be a significant likelihood that this would happen. If there were any probability of this, we would see it, because we are [closely] monitoring things,” Bilenko added.
In its monitoring effort, the Israel Neurological Association received a report of a single new case of multiple sclerosis documented in a vaccinated person, with two other flare-ups among those already known to have the disease. “That’s very low; at the same time, there were many people who didn’t get the vaccine who had flare-ups of MS,” said Ifergan, the neurologist from Soroka.
Panet added that the strongest evidence that the vaccine – which contains only a single protein with the code of the viral RNA – isn’t expected to cause autoimmune diseases is that the coronavirus itself hasn’t been found to cause autoimmune diseases, even though more than 117,000,000 people have been infected with the actual virus.
Does it pose a risk to fertility?
“Whoever made that up knows what’s important to the population,” said Belinko, referring to the population of Israel. The only thing on which such a fear-mongering tactic can be based is that there is a tiny similarity between the genetic sequence of the spike protein and a protein called syncytin contained in the placenta.
“The argument was that if you present the spike, and our body creates antibodies against it, these antibodies would also attack the placenta because of this similarity and cause miscarriages,” Sklan explained. The first problem with this claim, she said, is that the similarity between the proteins is too small for the immune system to generate a response to it.
“When you compare sequences on the computer, it’s common to find some homology [similarity] between two proteins,” Rechavi added. “But you have to understand that proteins are not unidimensional. They are folded into a space, and the immune system’s response and function are dependent on their three-dimensional structure. There is no similarity in the world between the spike protein and the placental protein. All of the experts agree that this is totally insignificant.”
Despite vast knowledge of biology, more than five years of medical trials and treatment with mRNA and tens of millions of people who have been vaccinated against the coronavirus so far, it cannot be said with 100 percent certainty that the vaccine won’t cause long-term side effects in anyone.
“Like any drug that’s taken and prescribed to millions of people, there are those who will develop side effects and complications,” said Rechavi, “and we take the medicines anyway.”