A second is on his heels. The two, one manufactured by Pfizer / BioNTech and the other by Moderna, mark the first time that this vaccine technology has been approved for use.
In trials, these vaccines have been shown to be at least 94% effective in preventing people from getting sick with Covid-19. But how safe is this new technology? We spoke with Michel Goldman, professor of immunology and founder of the I3h Institute for Interdisciplinary Innovation in Health at the Université Libre de Bruxelles in Belgium. Here are five things to know.
1. mRNA vaccine technology is not completely new
Vaccines, such as the inactivated polio vaccine, or most flu vaccines, use inactivated viruses to activate a person’s immune system to respond to the disease-causing organism. In other vaccines, such as the hepatitis B vaccine, an individual protein made by that body is injected instead to trigger a similar response.
However, mRNA vaccines trick the body into producing the viral protein itself, which in turn triggers an immune response.
Although the COVID-19 vaccines made by Pfizer / BioNTech are the first mRNA vaccines to complete all stages of clinical trials and be licensed for use, the technology has been around for a while.
There have been human trials of cancer vaccines using the same mRNA technology since at least 2011. “If there was a real problem with the technology, we would have seen it sooner for sure,” said Professor Goldman.
Because the technology can be deployed extremely quickly and clinical trials have been so successful, mRNA platforms will be an important means of preparing for future epidemics, he says.
2. mRNA vaccines do not alter your DNA
One concern some have had about mRNA vaccines is that they could change people’s DNA. But that idea is “completely false” and “has no scientific basis,” says Professor Goldman.
“The mRNA (from the vaccine) will not enter the nucleus of cells, where our DNA is.”
Once the injected mRNA enters a human cell, it breaks down rapidly and only stays in the body for a couple of days. That’s why people need two injections to develop the best immune response, he says.
3. mRNA vaccines are very specific
The new coronavirus, or SARS-CoV-2, has a complex structure, and different parts of the virus activate the immune system to produce different antibodies to neutralize the virus.
If an unvaccinated person contracts the virus, they will produce antibodies that prevent the virus from entering human cells. They can also generate antibodies that don’t have much of an impact. And in some cases, a person can make antibodies that actually help the virus enter cells.
MRNA vaccines are much more specific. They are designed to trigger only an immune response to the spike protein of the virus, which is just one component of the viral membrane and allows the virus to invade our cells.
To make sure this is the case, researchers are carefully monitoring that the vaccine does not trigger an unwanted immune response.
“So far this has not been proven for (Covid-19) vaccines.” But “it will remain important to ensure that the immune response triggered by the vaccine is focused on the viral spike protein,” said Professor Goldman.
4. No corners were cut in the clinical trials and approvals process
Vaccine trials are carried out in stages, starting with animal trials and then three human trials: Phase 1, Phase 2, and finally Phase 3.
More than 40,000 people participated in the phase 3 trial of the Pfizer / BioNTech vaccine. It started in July and will continue to collect efficacy and safety data for another two years.
Safety concerns that would affect a significant number of vaccines appear primarily within two months, says Professor Goldman.
However, after millions of people are given a vaccine, very rare side effects may develop that cannot be anticipated from clinical trials, so researchers and regulators will closely monitor how the vaccine is doing. launch of the vaccine. This will be especially important for Covid-19 vaccines based on innovative technology.
Regulatory agencies reviewed data from Covid-19 vaccine trials more quickly than usual, examining it continuously rather than just once the trials were completed, but they did not fundamentally change their rules. “I really don’t think corners have been cut in terms of safety,” said Professor Goldman.
The process was faster than usual because the researchers had already built an mRNA platform, a way to introduce viral mRNA into the body, for cancer and other vaccines under test. It meant that this could be put into action as soon as the genomic sequence of the virus was shared.
Companies and governments also risked producing a large number of vaccines even before the first stages of experimentation were completed, which meant they were ready to begin large human trials as soon as the results were received.
“It is a financial risk, because if you made a mistake, all this is lost. That is why risk is shared between private companies and governments, ”said Professor Goldman.
5. The vaccine triggers an inflammatory response
The vaccine works in part by inducing local inflammatory reactions to activate the immune system. This means that it is normal for many people to experience pain at the injection site and sometimes fever and malaise for a day or two after the vaccine.
“This is something that has not been advertised enough,” says Professor Goldman.
A November survey of 15 countries found that 54% of people were concerned about the possible side effects of the Covid-19 vaccine.
An unwanted response to the Pfizer-BioNTech mRNA vaccine came to light on the first day of mass vaccination in the UK after two people with a history of significant allergies reacted to the injection. The UK regulatory authority updated its advice to specify that people with a history of food or drug anaphylaxis should not be vaccinated.
In clinical trials, allergic reactions occurred in 0.63% of people who received the Pfizer-BioNTech vaccine and 0.5% of people who received a placebo.
“My main concern is that people use (possible side effects) as an argument not to get vaccinated,” said Professor Goldman. “The biggest risk right now (especially for vulnerable people) is not getting vaccinated.”
Original article
This article was originally published in Horizon, the EU Research and Innovation Magazine
