Are Covid mRNA Vaccines Risky? What the Experts Say: QuickTake

South Carolina Introduces New COVID-19 Vaccine Plan for More Equitable Distribution

Photographer: Micah Green / Bloomberg

When it became clear in early 2020 that the Sars-CoV-2 virus posed a pandemic threat, researchers who had been exploring an innovative way of making vaccines saw an opportunity. Experimental messenger RNA vaccines had been recognized for years for their potential speed and flexibility in a fast-moving epidemic, and were some of the first Covid inoculations to move to human trials. The effort paid off when, late last year, vaccines from Moderna Inc. and the Pfizer Inc./The BioNTech SE association was the first to demonstrate its effectiveness. However, because the technology is so new, these vaccines are particularly vulnerable to disinformation campaigns designed to discourage people from shooting.

1. How do mRNA vaccines work?

They work differently from previous generations of vaccines. Instead of introducing the body to an inactivated or weakened version of a virus or a part of it, they temporarily convert the body’s cells into small vaccine manufacturing factories. They do this by using synthesized versions of something called messenger RNA, a molecule that normally carries the genetic coding of a cell’s DNA into its protein-making machinery. In this case, the mRNA signals the body to make the spike protein that Sars-CoV-2 uses to enter cells. This, in turn, stimulates the body to produce long-lasting antibodies against the virus. Messenger RNA vaccines develop faster than traditional ones because their production does not require the growth of viruses or viral proteins within living cells. Furthermore, the modular nature of mRNA makes the design of new vaccines relatively straightforward. It took researchers just a few days in January 2020 to find the mRNA sequence used in Moderna’s Covid vaccine.

2. What do we know about its effectiveness?

In its phase 3 trial involving more than 30,000 participants, Moderna’s vaccine was 94% effective in preventing symptomatic cases of Covid, according to the company’s presentation to the US Food and Drug Administration. There were no cases of serious illness in people who received the vaccine, compared to 30 in the placebo group. Pfizer’s vaccine was 95% effective in stopping the disease in its phase 3 trial involving more than 43,000 participants, according to results published in the New England Journal of Medicine after the peer review process, in which the research is reviewed by experts in the same field. While there were fewer severe cases in that trial, the limited data supported protection against severe disease. Real-world results are starting to show up, but they’re looking good so far. Data from Israel’s largest healthcare organization found that after two doses, Pfizer’s injection was 94% effective against symptomatic Covid and prevented 87% of Covid hospitalizations, as reviewed by peers. published results.

3. What do we know about your safety?

Both vaccines can induce strong reactions, especially after the second injection, including headaches, muscle and joint pain, and fever. For example, in Moderna’s trial, after the second injection dose, most people under 65 experienced fatigue and muscle pain; about half had chills and 1 in 6 people had a fever. With both vaccines, these side effects are less common in older adults. After the vaccines were licensed, officials began to notice rare cases of severe allergic reactions. One theory is that these are caused by lipid nanoparticles that coat vaccines and help carry them into the body. These events are rare and range from 2 to 5 cases per million injections given, based on data as of Jan. 18 from the US Centers for Disease Control and Prevention. These can usually be treated with adrenaline, also known as epinephrine; a small minority of cases required intubation. A data study up to February 18, Massachusetts General Hospital suggested a higher rate of serious allergic reactions, roughly 2.5 cases per 10,000 shots, but still concluded that the overall risk “remains extremely low.” Meanwhile, a separate Mass General study showed that some people delayed rashes after receiving Moderna’s vaccine. Although sometimes dramatic, these eruptions are not dangerous, the researchers said.

4. Who spreads misinformation about vaccines?

Traditional anti-vaccine activists have joined forces with figures in the alt-right, a primarily online political movement based in the United States whose members espouse extremist beliefs typically centered on ideas of white nationalism. High-profile conservatives, including Fox News personality Tucker Carlson has raised questions about Covid vaccines in general. According to the US State Department, Various Online Platforms linked to Russian intelligence have spread misinformation about mRNA vaccines; Moderna and Pfizer are US-based companies. A Kaiser Family Foundation The survey found that those who reject the vaccine are disproportionately dependent on Facebook for information, while people who want the vaccine are more likely to read newspapers or watch television news.

5. What are they saying?

  • Those steps were skipped when developing and licensing the vaccines – it’s true that the vaccines hit the market in record time, but that’s not because the testing steps were skipped. The companies sped up the process by running a few testing steps in parallel, and in the case of Moderna’s vaccine, the US government took financial risks by paying to upgrade manufacturing before results were achieved.
  • Vaccines have never been approved by the FDA: That’s true in the sense that the agency has only granted authorization for emergency use so far. This is a Pre-existing mechanism created to accelerate access to medical countermeasures in the event of a public health emergency such as the Covid pandemic. the The FDA established in advance that to obtain authorization, Covid vaccines had to be shown to be at least 50% effective in preventing disease in large-scale trials and had to demonstrate safety with two months of follow-up data from trial participants. . In addition, the vaccines were reviewed by a panel of independent advisers. Both Moderna and Pfizer have said they plan to apply for regular approval of the vaccines this year.
  • Critics have embraced the labeling of mRNA vaccines as a form of gene therapy, hinting that the injections could somehow alter your DNA – they don’t. Although the messenger RNA they use is a type of genetic material, vaccines differ from what is normally considered gene therapy because they don’t change the DNA inside cells. “They do not affect or interact with our DNA in any way,” the Centers for Disease Control and Prevention Explain. In fact, mRNA molecules from vaccines, which are short-lived, do not enter the nucleus of cells, where DNA is stored, the CDC notes.
  • That lipid nanoparticles in vaccines may contain antifreeze: that’s not true. Antifreeze contains ethylene glycol, which is toxic. Instead, lipid nanoparticles include polyethylene glycol, an inert compound found in everyday products like toothpaste and shampoo and in many medications, including laxatives.
  • That vaccines can cause antibody-dependent enhancement, or a worse case of illness in those who become ill despite inoculation – this was a theoretical concern when testing of Covid vaccines began. There was evidence of this problem in animal studies of some vaccines for severe acute respiratory syndrome (SARS), which is caused by a coronavirus related to SARS-CoV-2. However, no indication of this emerged in human trials of mRNA vaccines for Covid, according to Stanley Perlman, a coronavirus researcher at the University of Iowa, who served on the FDA advisory panel that reviewed vaccines.
  • That we don’t know the long-term effects of vaccines – that’s always the case with new vaccines. But the side effects of the vaccine usually appear within the first months after vaccination, which is why the FDA insisted on two months of safety data before authorizing it. Reports of adverse events since then have not detected patterns of death that indicate a problem with the vaccines, says the CDC.
  • That there are more reports of adverse events for Covid vaccines than for influenza vaccines – that’s not an appropriate or meaningful comparison, says Aaron Kesselheim, professor of medicine at Harvard Medical School. The number of these reports tends to spike when a treatment or vaccine makes the news, and nothing has been more in the headlines than Covid vaccines. In the US, these reports can be submitted by anyone and does not constitute confirmation that a vaccine caused an adverse event. Given the large number of vaccines, some unfortunate people will get sick and even die shortly after receiving the injections, regardless of the vaccine.

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