The UK health authorities approved the Pfizer / BioNTech coronavirus vaccine for widespread use, the first country in the world to do so. But while many people want to get an injection as soon as possible, others worry about introducing something unknown into their body.
Here we clear up some doubts that the news about vaccines raises.
How do we know that a vaccine is safe?
This is the first, and most important, question scientists ask when they begin to design and test a new vaccine or treatment.
Safety testing begins in the laboratory, with tests and research in cells and animals, before moving on to human studies.
The procedure requires starting small and only proceeds to the next testing stage if there are no outstanding security issues.
What role do essays have?
If the safety data from laboratories is good, scientists can verify that the vaccine or treatment is effective.
That means testing a large number of volunteers, about 40,000 people in the case of Pfizer / BioNTech.
In the trials, half of the people are given the vaccine and the other half a sham or placebo injection.
To avoid bias, neither the researchers nor the participants are told which group they belong to until the results have been analyzed.
All work and findings are independently reviewed and verified.
Covid vaccine trials-19 have been done at breakneck speed, but none of these steps have been skipped.
The Oxford / AstraZeneca vaccine trials were voluntarily stopped at one stage to investigate why one participant, out of many thousands, had died. It was restarted once it became clear that what happened was not related to the vaccine.
Who approves vaccines or treatments?
A vaccine is only approved if the government regulator – in the case of the United Kingdom it is the Medicines and Health Products Regulatory Agency (MHRA) that depends on the Department of Health – is satisfied and considers that it is safe and effective.
After the MHRA became the first agency in the world to approve a covid-19 vaccine, its director, June Raine, said: “The public can be absolutely sure that the standards we have worked with are equivalent to the of all the world”.
Now the vaccine checks will continue to make sure there are no more side effects or long-term risks.
In the United States, the body in charge of approving any vaccine against covid-19 is the Food and Drug Administration (FDA).
Once a vaccine is licensed, the FDA continues to monitor production and evaluate batches to monitor for potential unwanted effects and to ensure that it remains safe and effective.
A similar situation occurs in Latin America.
In Mexico, for example, the body in charge of approving vaccines against covid-19 is the Federal Commission for Protection against Sanitary Risks (Cofepris), of the Ministry of Health.
The Undersecretary of Prevention and Health Promotion, Hugo López-Gatell, said in late November that Pfizer / BionTech had already delivered “The health registration application file” from the covid-19 vaccine to Cofepris and, therefore, we are waiting for a response.
What do covid-19 vaccines contain?
There are many different vaccines in development for Covid-19.
Some contain the pandemic virus in a weakened form.
The Oxford / AstraZeneca vaccine uses a harmless, altered virus.
The Pfizer / BioNTech and Moderna vaccines use fragments of genetic code to elicit an immune response and are called mRNA vaccines.
These fragments do not alter human cells, they only present the body with instructions to develop immunity against COVID-19.
Other immunizations for covid contain coronavirus proteins.
Vaccines sometimes contain other ingredients, such as aluminum, that make the vaccine stable or more effective.
Will a vaccine make me sick?
There is no evidence that any of these ingredients cause harm when used in such small amounts.
Vaccines do not cause disease. Instead, they teach the immune system to recognize and fight the infection they have been designed against.
Some people experience mild symptoms, such as muscle aches or a slight fever, after being vaccinated.
This is not the disease itself, but the body’s response to the vaccine.
Allergic reactions to vaccines are rare.
Professor Sir Munir Pirmohamed, who advises the MHRA, said that he had not identified any “serious adverse reactions” during the Pfizer / BioNTech vaccine trial.
“Most of the adverse effects were mild and of short duration, generally they lasted one or two days, similar to the type of effects produced after any other vaccine, ”he said.
Is it sure that someone who has had already covid-19 get vaccinated?
Even people who have had COVID-19 in the past are likely to be offered the vaccine.
That’s because natural immunity may not last long, and immunization may offer more protection.
Health authorities in England state that there are no safety concerns in giving the vaccine to people who have suffered from long-term covid-19.
But those currently suffering from Covid-19 should not receive the vaccine until they have recovered.
¿Are vaccines against covid-19 respectful of animal welfare?
Some vaccines, such as the herpes vaccine and the nasal infant flu vaccine, may contain pork gelatin.
And some vaccines are made in chicken eggs or chicken embryo cells.
There are hundreds of covid-19 vaccines in development.
We don’t have details on all the ingredients yet, but many of the vaccines are expected to be suitable for vegetarians or vegans.
If everyone gets the vaccine, then I no longer need to?
There is overwhelming scientific evidence that vaccination is the best defense against serious infections.
Covid-19 vaccines appear to prevent people from getting seriously ill and could save lives.
The first doses that are available will likely be offered to people in greatest need, such as the elderly, who are in the highest risk group.
It is not yet clear how much protection vaccines could provide in terms of preventing people from spreading Covid-19.
If the process can be done well, vaccinating enough people could stop the disease.
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