Photographer: Micah Green / Bloomberg
Photographer: Micah Green / Bloomberg
When it became clear in early 2020 that the Sars-CoV-2 virus posed a pandemic threat, the researchers who were exploring an innovative way of making vaccines saw an opportunity. Experimental messenger RNA vaccines have been recognized for years for their potential speed and flexibility in a rapidly evolving epidemic, and were some of Covid’s first inoculations to be tested in humans. The effort paid off when, at the end of last year, vaccines for Moderna Inc. and Pfizer Inc./The BioNTech SE partnership was the first to prove effective. Because the technology is so new, however, these vaccines are particularly vulnerable to disinformation campaigns designed to dissuade people from shooting.
1. How do mRNA vaccines work?
They work differently than previous generations of vaccines. Instead of presenting the body with an inactivated or weakened version of a virus or a fragment of it, they temporarily transform the body’s cells into small vaccine factories. They do this using synthesized versions of something called messenger RNA, a molecule that normally carries a cell’s genetic code to its protein-making mechanism. In that case, the mRNA instructs the body to produce 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 are faster to develop than traditional vaccines because their production does not require the growth of viruses or viral proteins within living cells. In addition, the modular nature of mRNA makes designing new vaccines relatively simple. The researchers took only a few days in January 2020 to arrive at the mRNA sequence used in the Covid vaccine from Moderna.
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 Covid’s symptomatic cases, according to the company’s filing with the US Food and Drug Administration. There was no case of serious illness in people who received the vaccine, versus 30 in the placebo group. The Pfizer 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 examined by experts in the same field. Although there were fewer serious cases in that trial, the limited data was consistent with protection against serious illnesses. Real-world results are just beginning to show, but they look good so far. Data from Israel’s largest health organization found that, after two doses, the Pfizer injection was 94% effective against symptomatic Covid and prevented 87% of Covid hospitalizations, according to a peer review published results.
3. What do we know about their safety?
Both vaccines can induce strong reactions, especially after the second injection, including headaches, muscle and joint pain and fever. For example, in the Moderna trial, after the second injection dose, most people under the age of 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 vaccines were authorized for use, officials began to notice rare cases of severe allergic reactions. One theory is that these are caused by lipid nanoparticles that line vaccines, helping to transport them to the body. These events are rare, ranging from From 2 to 5 cases per million injections administered, according to data as of January 18 from the United States Centers for Disease Control and Prevention. They can usually be treated with adrenaline, also known as epinephrine; a small minority of cases required intubation. A study of data up to February 18, Massachusetts General Hospital suggested a higher rate of serious allergic reactions, about 2.5 cases per 10,000 shots, but still concluded that the overall risk “remains extremely low”. Meanwhile, a separate study by Mass General showed that some people manage to delayed rashes after receiving the Moderna vaccine. Although sometimes dramatic, these rashes are not dangerous, the researchers said.
4. Who is spreading misinformation about vaccines?
Traditional anti-vaccine activists are increasingly joined forces with figures in the alt-right, a mostly 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 raised doubts about Covid vaccines in general. According to the U.S. Department of State, several online platforms linked to Russian intelligence have spread misinformation about mRNA vaccines; Moderna and Pfizer are companies based in the United States. Kaiser Family Foundation The survey found that those who refuse the vaccine disproportionately depend on Facebook for information, while people who want the vaccine are more likely to read newspapers or watch news on TV.
5. What are they saying?
- These steps were skipped in the development and authorization of vaccines: it is true that vaccines hit the market in record time, but not because no test step was skipped. The companies accelerated the process by carrying out some testing steps in parallel, and in the case of Moderna’s vaccine, the United States government took financial risks by paying to speed up manufacturing before the results arrived.
- Vaccines have never been approved by the FDA: This is true in the sense that the agency has only given emergency use authorization so far. This is a pre-existing mechanism designed 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, in order to obtain authorization, Covid vaccines needed to prove to be at least 50% effective in preventing disease in large-scale tests and demonstrate safety with two months of follow-up data from the test participants. In addition, the vaccines were examined by a panel of independent consultants. Both Moderna and Pfizer said they plan to request regular vaccine approval this year.
- Critics have started to label mRNA vaccines as a form of gene therapy, implying that injections can somehow alter their DNA: they do not. Although the messenger RNA they employ is a type of genetic material, vaccines differ from what is normally considered gene therapy in which they do not alter the DNA within the cells. “They do not affect or interact with our DNA in any way,” the Centers for Disease Control and Prevention explains. In fact, the vaccine’s mRNA molecules, which are short-lived, do not enter the cell nucleus, where the DNA is stored, notes the CDC.
- That lipid nanoparticles in vaccines may contain antifreeze: This is not true. The antifreeze contains ethylene glycol, that is toxic. Lipid nanoparticles, instead, include polyethylene glycol, an inert compound found in everyday products, such as toothpaste and shampoo, and in many medications, including laxatives.
- That vaccines can cause an antibody-dependent increase or worse case of disease in those who fall ill despite inoculation: that was a theoretical concern when testing for Covid vaccines began. There have been indications of this problem in animal studies of some vaccines for severe acute respiratory syndrome (SARS), which is caused by a SARS-CoV-2-related coronavirus. However, no indication of this has emerged in human trials of mRNA vaccines for Covid, according to Stanley Perlman, a coronavirus researcher at University of Iowa, who served on the FDA advisory panel that reviewed the vaccines.
- That we don’t know the long-term effects of vaccines: this is 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 them. Adverse event reports have since detected no death patterns that would indicate a problem with vaccines, says the CDC.
- That there are more reports of adverse events for Covid vaccines than for flu vaccines: this is not an appropriate or meaningful comparison, says Aaron Kesselheim, professor of medicine at Harvard Medical School. The number of such reports tends to increase when a treatment or vaccine is in the news, and nothing has made more headlines than Covid’s vaccines. In the USA, these reports can be presented by anyone and does not constitute confirmation that a vaccine caused an adverse event. Given the large number of vaccines, some unhappy people will get sick and even die shortly after receiving the vaccines, regardless of the vaccine.