Although the United States Centers for Disease Control and Prevention (CDC) recommends not combining brands, several countries are already doing so.
Typically, if the person receives a covid vaccine that requires two doses, the two doses are administered from the same pharmaceutical company or laboratory, for example, two from Pfizer, two from Moderna, two from Sputnik, two from Covishield, etc.
However this may change, either out of necessity, because there is a shortage of a type of vaccine, or because the vaccine design is modified. In fact, for example in Canada, Germany, Spain and France, people are already being encouraged to receive a first dose of AstraZeneca and a second dose of what is available, even if it is from different pharmaceuticals.
Basically, vaccines act the same: educating the immune system so that recognizes the coronavirus and destroys it. Giving him two different doses, with two different formulations, is like showing him two photos of the same virus, but from a different angle, experts say.
It is like helping the immune system to recognize a pathogen from different ways.
Are there any risks? Scientists agree that no.
A study completed in Spain showed that combining a first dose of the AstraZeneca vaccine with a second one from Pfizer produced a strong immune response.
Other similar scientific research conducted in Germany obtained similar results.
It is not something that has been tested with all vaccines. However, if other studies show that other combinations generate the same immune potential, this would help to speed up the vaccination process globally.
And especially it would eliminate the problem of a shortage of a brand , since the doses could be completed with another.
The vaccination strategies have been different depending on the country. In the United States, where some states have already reached or exceeded 70% of their vaccinated population, the vaccination initiative promotes receiving both doses of Moderna’s vaccines. and Pfizer three to four weeks apart. (Johnson & Johnson’s is a single dose).
However, in Italy, for example, the strategy has been to extend the period between vaccines until 12 weeks (something that is known does not affect the “training” process of the immune system), so that more people received the first dose.
Different paths, the same goal
The vaccine contains substances that act by neutralizing the action of a protein that helps the coronavirus to infect the human body. In addition, when immunized, the body is left with a supply of T lymphocytes and B lymphocytes that will remember how to fight that virus in the future.
Currently, there are three main types of COVID vaccines – 19 that have been developed. They all serve the same goal of teaching the immune system to recognize pathogens and eliminate or weaken them. They are as follows:
mRNA vaccines. These vaccines contain material from the virus that causes covid – 19. This material “teaches” cells how to make a harmless protein that is unique to the virus. Once the cells make copies of the protein, they destroy the genetic material in the vaccine.
If the virus is contacted, the body will recognize that the protein should not be there and will produce T lymphocytes and B lymphocytes that they will remember how to fight the virus that causes covid – 19. That is, they will prevent infection
Vaccines with protein subunits. These vaccines contain parts harmless (proteins) of the virus that causes covid – 19, but they do not contain all the germ.
When vaccinated, a person’s immune system recognizes that proteins do not belong in the body and begins to produce T lymphocytes and antibodies. If in the future the person becomes infected, the cells, which memorized this protein, will recognize it and fight against the virus.
Vector vaccines. These vaccines contain a weakened version of a live virus, different from the one that causes covid – 19, which has genetic material from the virus that cause covid – 19 inserted into it (this is called viral vector).
Once the viral vector is inside the cells, the genetic material “instructs” the cells to produce a protein that is unique to the virus that causes covid – 19.
Using these instructions, cells make copies of the protein. This prompts the body to produce T lymphocytes and B lymphocytes that will remember how to fight that virus if the person becomes infected in the future.
The reality is that there is probably no possibility of choosing which vaccine use because depending on the departments, municipalities, countries there will be certain vaccines available. All available vaccines are effective and safe.
It usually takes a few weeks for the body to produce T lymphocytes and B lymphocytes after vaccination to produce immunity. The average is 14 days.
Therefore, it may be possible for a person to become infected with the virus that causes covid – 19 just before or just after vaccination and then you get sick because the vaccine didn’t have enough time to provide protection.
What is known from experience with other vaccines is that, if a vaccinated person becomes infected, surely, if he develops it, he will have a mild form of the disease.
Sources: scientific studies, Science Magazine, CDC.