Vaccination against COVID-19 is a controversial topic, especially since vaccines were developed in a short time to try to combat the global pandemic caused by the new coronavirus. For this reason, many doubts and myths have arisen about the vaccine, especially related to its safety and efficacy.
Vaccine remains the most effective way to prevent serious COVID-19 infection, which can lead to hospitalization and be life-threatening. Learn more about vaccines against COVID-19.
The following is a list of the most frequently asked questions, explained and clarified based on scientific evidence.
1. Is the vaccine safe?
The COVID-19 vaccine has undergone several tests to ensure its effectiveness, safety and quality. Regardless of the laboratory and type of vaccine, all have been duly approved by the WHO and other he alth authorities (such as Anvisa, FDA, EMA or Infarmed) and are considered safe.
2. Who can get the vaccine?
Everyone can get the COVID-19 vaccine. However, it is advisable to consult the doctor in some specific situations, such as having a previous history of allergies, especially to some type of vaccination, or having a weakened immune system, such as in cases of cancer, transplants and other treatments that make it difficult for the system to function. immune.
3. Can I get the vaccine if I have a fever, cough or have the flu?
The vaccine is not recommended in cases of fever, cough and flu, since the immune system is more fragile in these situations.In addition, as the symptoms of COVID-19 can be confused with those of the flu, it is recommended to remain in isolation and follow all guidelines for a suspected case. See what to do if you suspect COVID-19.
4. Can anyone with COVID be vaccinated?
The COVID vaccine is not suitable for people who are sick, because there are still no studies that prove the effectiveness of vaccination for these cases. In addition, people with COVID must remain in isolation to prevent transmission of the disease.
In Brazil, it is recommended to take the vaccine only at least 30 days after the onset of COVID symptoms. In the case of Portugal, the vaccine is recommended 6 months after the diagnosis of COVID-19.
5. Can I get the COVID vaccine along with the flu shot?
According to the Brazilian Ministry of He alth, COVID-19 and flu vaccines can be administered on the same day. This is because the most frequent effects and the effectiveness of vaccines against COVID-19 are already known, and there is no interference from the vaccine applied against the flu.
Although they can be applied on the same day, the recommendation is that the application be carried out in different muscle groups, such as one in each arm, for example, or, if this is not possible, it can be applied in the same group muscle as long as there is a distance of 2.5 cm between the two.
6. Is the vaccine 100% effective?
No vaccine is considered 100% effective in preventing COVID-19 or any other infection. However, most vaccines against COVID-19 guarantee almost total protection against the most serious forms of the disease, which reduces the risk of hospitalization and death. Know the effectiveness rate of each COVID-19 vaccine.
Some factors that can affect the effectiveness of the vaccine are:
- Older age;
- Immune system compromised, as in cases of autoimmune diseases or cancer treatment, for example;
- Associated diseases such as hypertension, diabetes or respiratory problems.
These factors decrease the immune system's ability to create a robust response against the virus, decreasing the vaccine's effectiveness. Still, vaccination remains the best way to train the body and reduce the risk of having a serious infection.
Non-vaccination does not protect against COVID-19 infection or severe forms of the disease.
7. How effective is the vaccine against COVID variants?
According to the WHO , all current vaccines are very effective against all current variants of the coronavirus, helping to prevent hospitalizations and deaths caused by COVID-19. Understand how the vaccine is effective against the new variants.
However, it is important to remember that no vaccine prevents contagion, and therefore, it is essential to maintain general preventive care against the disease, even after complete vaccination, such as washing your hands with soap and water with frequency, and wear personal protective masks.
8. Is the vaccine mandatory?
The vaccine against the new coronavirus is provided free of charge and is voluntary, that is, it should only be done by those who wish to vaccinate, and it is not mandatory. Even so, he alth authorities recommend vaccination as a means of individual and collective protection and to help control the pandemic.
9. Can I drink alcohol after vaccination?
Consumption of alcoholic beverages after vaccination does not interfere with the effect of the vaccine against COVID-19. However, it is advisable that alcohol consumption be done in a moderate way, since excess alcohol, in addition to having several negative effects on he alth in general, decreases the response of the immune system. In addition, alcoholic beverages can intensify the side effects of the vaccine, such as tiredness and headache.
10. Can breastfeeding people get the vaccine?
Breastfeeding women can get the COVID-19 vaccine, because none of the current vaccines contain the live virus of the new coronavirus. This means that there is no risk of transmitting COVID-19 through breast milk to the baby.
In addition, the vaccine stimulates the mother's immune system to produce antibodies against the disease, helping to protect the baby against COVID-19.
11. Can pregnant women take the vaccine?
To date, there are few studies carried out with pregnant women that can ensure the safety of the vaccine against COVID-19. For this reason, the vaccination recommendation varies according to the he alth authority of each country.
In Brazil , vaccination during pregnancy can only be done with a doctor's prescription in all pregnant women over 18 years of age, with a recommendation to avoid vector vaccines viral, which is why Pfizer and Coronavac vaccines are recommended.
In Portugal , vaccination can be performed in pregnant women aged 16 or over, after 21 weeks of gestation, after undergoing a morphological ultrasound and at an interval 14 days for any other vaccine.
12. How long does the vaccine take to take effect?
The COVID-19 vaccine takes a few weeks to take effect and offer protection against the disease, as the body needs time to produce the antibodies that will ensure immunity against the virus. Thus, people who had contact with the virus in the weeks before vaccination, or immediately after receiving the vaccine, can still develop infection, as the body does not yet have the necessary antibodies to fight the disease.
It is also important to remember that, in the case of vaccines that require 2 different doses, the highest protection rate occurs only 2 to 3 weeks after the 2nd dose.
13. How long does the immunity conferred by the vaccine last?
The duration of immunity conferred by the vaccine is not yet known, however, current studies suggest that protection against serious illness and death lasts for a period of 4 to 6 months, gradually decreasing thereafter. Still, more studies will be needed.
Due to this possibility of diminishing vaccine protection, most he alth authorities have approved the administration of booster doses after the initial vaccination. Understand better what a booster dose is and when to take it.
14. What are the booster doses of the vaccine?
The booster doses of the COVID-19 vaccine are indicated to reinforce immunity, being given within a period of 4 to 6 months after the initial full vaccination.
Currently there are 3rd and 4th doses of the COVID-19 vaccine and recommendations vary according to the person's age and occupation. See when to take the 3rd and 4th doses of the vaccine.
15. Does anyone who has had COVID-19 need to be vaccinated?
Vaccination against COVID-19 is indicated even for those who have already had the disease, since studies show that it is possible to develop the infection again.
16. What adverse reactions can arise?
Like any other type of vaccine, the COVID-19 vaccine can also cause some reactions, such as pain, swelling and redness at the injection site. In addition, some people may also experience tiredness, muscle pain, fever and headache. These symptoms are usually mild and tend to disappear within a few days. See the most common adverse reactions and what to do to treat each one.
17. Can I delay the 2nd dose of the vaccine?
Ideally, the second dose of the vaccine should be given within the stipulated period, as this ensures that the booster is given at the peak of antibody production that occurs after the first dose.
However, if vaccination is not possible on that date, it is recommended that the second dose be performed as soon as possible. This is because, although the first dose does not fail to have an effect, the effectiveness of the vaccine is only guaranteed after both doses are administered.
Thus, the second dose should be taken according to the manufacturer's recommendations:
- Coronavac: 2 to 4 weeks;
- Pfizer and BioNTech: 21 to 28 days;
- Modern: 28 days;
- Covaxin: 28 days;
- Astrazeneca: 8 weeks;
- Sputnik V: 21 days.
Where possible, WHO recommends that both doses be of the same vaccine. However, if this is not possible, the second dose must be given with another vaccine of the same type.
18. Is it necessary to repeat the vaccination periodically?
It is not yet known how long the COVID-19 vaccine confers immunity, so it is not possible to say whether vaccination will need to be done periodically. However, if protection is found to be short-lived, it may be necessary to carry out periodic vaccination, especially for higher risk groups.
18. Can I get sick from getting the vaccine?
None of the approved vaccines against COVID-19 contain the live virus in their composition. For this reason, the vaccine is not capable of causing COVID-19. See how the main vaccines against COVID-19 work.
20. Is it possible to transmit the virus after being vaccinated?
The vaccine only protects against the development of severe infection, which means that a vaccinated person, while at little risk of developing symptoms, can still carry and transmit the virus to others.
21. Does the vaccine alter DNA?
No type of vaccine against COVID-19 causes changes in DNA. Although some vaccines contain pieces of the mRNA of the virus, these pieces do not change the DNA of the cells, only stimulating the immune system to produce antibodies capable of fighting the virus.
22. Should I continue to wear a mask after vaccination?
Since vaccination does not prevent transmission of the virus, it is recommended that, even after vaccination, individual protection measures are maintained, such as wearing a mask, frequent hand washing and social distancing.
23. Is it true that the vaccine can cause infertility?
There is no scientific evidence that vaccines against the new coronavirus can cause infertility.
24. Who should not be vaccinated against COVID-19?
There is no definite contraindication against COVID-19 vaccination. However, pregnant women, children under the age of 16, and people with any type of serious illness that can affect the immune system, such as cancer, should always discuss the possibility of vaccination with a doctor.