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In February 2023, health centers throughout Brazil started to vaccination against Covid-19 with Pfizer’s bivalent vaccine, the most current version and composed of the original strain of the coronavirus and the omicron variant. The goal is to continue protecting Brazilians against the advances of the disease. However, not everyone has had at least the first two doses of the vaccine.
Taking at least the first two doses means, by definition, having completed the primary vaccination schedule. This is because it is considered the minimum necessary to guarantee individual protection and that of all Brazilians.
What break to take the Covid 19 vaccine?
Whether due to lack of information, fear of adverse reactions, or even a sense of security in the face of the drop in new cases of Covid-19, many people stopped taking all the necessary doses.
Even if the full scheme only includes the first two doses, experts recommend keeping all Covid-19 vaccinations up to date, including the booster doses that have already been recommended.
In the case of adults, for example, vaccination against the coronavirus began in 2021 and, until then, in addition to the primary scheme consisting of the two initial doses, at least two more booster doses have already been applied. In the case of immunosuppressed patients, the primary scheme includes the application of three doses of the monovalent vaccine.
Bivalent vaccines vs monovalent vaccines
With the arrival of bivalent vaccine from Pfizer, the priority groups that have completed the vaccination cycle can now take the new vaccine. Those who have not taken at least two doses will have to complete this primary cycle and then take the bivalent vaccine.
“People have completed the vaccination cycle by taking only the two primary doses of the vaccine against Covid-19, but we recommend that the entire population also take additional booster doses. The vaccination cycle that we consider ideal to guarantee the protection of the patient includes all doses: the two initial ones and the booster ones”, emphasizes the infectologist Emy Akiyama Gouveiado Hospital Israelita Albert Einstein.
Gouveia also points out that people who are not in the priority group and have not completed the primary vaccination cycle should end their vaccination schedule with the monovalent vaccine, as these immunizers continue to avoid deaths and serious scenarios of the disease.
Risk of new waves of Covid-19
A person who does not complete the vaccination cycle, in addition to putting himself or herself at risk (by not having the protection considered ideal), also contributes to the virus continuing to circulate and mutating frequently.
The increase in mutations gives rise to new variants, some without relevance, but others can become stronger and cause important impacts on public health, with an increase in cases, the severity of the disease, hospitalizations or mortality.
Generally, this happens because months after vaccination there is a natural drop in the antibodies that the body produced induced by the vaccine. That is, over time, the person can contaminate himself even though he is vaccinated (only in a lighter and even asymptomatic way).
However, the virus can trigger new waves of infection (therefore, there was a need for booster doses).
An example of this vaccine escape happened with the delta variant of the coronavirus, discovered in India. She was resistant to the vaccines available at the time, causing important waves of contamination with serious cases, hospitalizations and deaths.
Another example was the appearance of the omicron variant, which also caused new peaks in transmission and contamination and once again overloaded the health system with hospitalizations due to the disease.
These outbreaks happen because when coming into contact with an organism that is not fully immunized, the virus gains strength and continues to be transmitted. Thus, the more individuals are vaccinated, the lower the chances of new variants continuing to emerge, and the closer the control of Covid-19 becomes.
Priority groups in the vaccination schedule
In the elderly, who are included in the priority group (read more below about who is the target audience and dates in 2023) In the current vaccination scheme, the complete vaccination cycle against Covid-19 is extremely important for two reasons:
- There is a natural reduction in the amount of antibodies that the body produces induced by vaccination and this allows the virus to mutate;
- The immune system of elderly people is more vulnerable and they maintain protection for less time compared to younger people.
The main objective of the vaccine is to make the body of the population acquire a kind of “immunological memory”. This happens by introducing the pathogenic agent (in this case, the coronavirus) to stimulate the body to generate an immune response, producing antibodies that react to fight the “invader”.
Together, with preventive care such as wearing a mask and frequently sanitizing your hands with water and soap or gel alcohol… keeping the immunization cycle up to date is one of the main weapons in the fight against the new coronavirus and also several other diseases.
Therefore, having the complete vaccination cycle against Covid-19 is essential to reduce its contamination and prevent the occurrence of serious cases of the disease, which also reduces mortality rates worldwide.
Covid-19: forecast for application of the bivalent vaccine by priority groups in 2023
⦁ Seniors over 70 years old;
⦁ People who live in long-stay institutions from 12 years old and their workers;
⦁ Immunocompromised patients over 12 years old (those living with HIV, transplant recipients, patients with chronic kidney disease on hemodialysis, patients who have undergone chemotherapy or radiotherapy in the last six months, patients with inborn errors of immunity, among others);
⦁ Indigenous, riparian and quilombola people over 12 years of age;
⦁ Elderly aged between 60 and 69 years old;
- Pregnant women and postpartum women (up to 45 days after delivery;
⦁ Health workers;
⦁ Persons with permanent disabilities over 12 years old;
⦁ Population deprived of liberty and adolescents complying with socio-educational measures;
⦁ Employees of the deprivation of liberty system;
Forecast of the application of the monovalent Covid-19 vaccine
⦁ Children from six months to 4 years old receive the Pfizer vaccine;
⦁ Children aged 5 to 11 receive Pfizer or CoronaVac, as do adolescents aged 12 to 17;
⦁ Adults aged 18 to 39 receive Pfizer or CoronaVac;
⦁ Adults over 40 years old can receive Pfizer, CoronaVac, AstraZeneca or Janssen;
Which vaccine is most indicated according to age group?
⦁ 6 months to 4 years: 3 doses of Pfizer;
⦁ 3 to 4 years: 3 doses of Pfizer or 2 doses of CoronaVac plus a booster, preferably Pfizer;
⦁ 5 to 11 years old: 2 doses of Pfizer or 2 of CoronaVac, with reinforcement preferably from Pfizer;
⦁ 12 to 17 years old: 2 doses of Pfizer or 2 of CoronaVac, with reinforcement preferably from Pfizer;
⦁ 18 to 39 years old: 2 doses of Pfizer or 2 of CoronaVac, with reinforcement preferably from Pfizer;
⦁ 40 to 59 years: 2 doses of Pfizer, CoronaVac, AstraZeneca, Janssen with 2 booster doses, the second preferably with Pfizer.