In October 2021, in Ecuador the application of the dose reinforcement against covid-19. For this process, the biologicals of Pfizer y AstraZenecaindependently of the formula previously applied.
That is, if the person received both doses of Pfizer (messenger RNA or mRNA) or Sinovac (inactivated virus), the booster is done with AstraZeneca.
The guideline for immunization of the reinforcement of the Ministry of Health points out that the results of clinical studies show that heterologous schemes that incorporate mRNA-type vaccines (Pfizer-BionTech) and inactivated viruses, which are then boosted with adenovirus vector vaccines (AstraZeneca), produce a strong cellular and humoral response, comparable to those homologous schemes.
This combination also applies to the second booster. This vaccine, which is administered from April 1, 2022, is received by people over 50 years of age and the prioritized population after five months from the third dose.
The document of Ministry of Health recommends that if a person received Pfizer in the first booster, in the second it can be placed AstraZeneca or one vaccine of the same brand.
Likewise, if AstraZeneca was applied, the same or Pfizer is suggested as a second booster; and if you received Sinovac AstraZeneca or Pfizer is recommended. All according to availability of the vaccine.
better immune response
About, Washington Cardenasa professor at the Escuela Politécnica del Litoral (Espol), points out that studies have been published on an international scale showing that the immune response was equal to or better with the mixed scheme.
The specialist refers to a research, published in June 2021; there it is pointed out that combining a first dose of AstraZeneca and a second of Pfizer generated more antibodies and T cells (immune cells that kill pathogens) than using two of AstraZeneca.
Also, that using Pfizer first and then AstraZeneca was more beneficial to use twice british vaccinealthough not as effective as using them in reverse order.
In the case of boosters, if a shot is less effective than another, these mixed schemes could ensure that people who have received a less effective dose can receive a reinforcement with a more efficient
A more recent study from the University of Oxford revealed that a third dose with a vaccine produced by AstraZeneca, Pfizer-BioNTech, or Johnson & Johnson increases the levels from antibodies of those who previously received two doses of Sinovac.
Last December, the European Medicines Agency (EMA) and the European Center for Disease Prevention and Control (ECDC) also endorsed the dose combination. “A heterologous booster appears as good or better in terms of immune responses than a homologous booster,” they stated.
reduce transmission
The biotechnology expert, Jhommara Bautista, explains that the immune response increases either by the combination of vaccines or with the same one because the objective of the reinforcement is to give the organism the mechanism to produce again antibodies.
He mentions that with two doses against covid-19 the immune system has protection, however, this is reduced in a period of between four and six months so it is necessary Be placed a third dose, of the same as the previous two or another.
Bautista recalls that being in a pandemic it is important to achieve a community protection. He points out that being immunized reduces the transmission rate because you have higher antibody levels and are less likely to get an infection after vaccination and also to transmit the virus to other people.
Dose
Three doses of the Pfizer/BioNTech compound will be given to children between the ages of 12 and 15 in the United States.
Children between 5 and 11 years old with deficiencies in the immune system will also be able to access the third dose.
Children between the ages of 5 and 11 began receiving their first anti-Covid-19 injections last November.
In Ecuador, the Ministry of Health has not yet authorized the application of the reinforcement of the anticovid-19 vaccine for children between 5 and 12 years of age.
The vaccination of this group in Ecuador began in October 2021. The Chinese Sinovac vaccine is applied.
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