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How do COVID vaccine doses work for children?

How do COVID vaccine doses work for children?

Dining keys

  • The dose of the pediatric vaccine is still being refined.
  • Two doses will probably be needed about three weeks apart.
  • It is unknown at this time what he will do after leaving the post.

Although scientists have established an appropriate effective dose of COVID-19 vaccine for adults, they have not yet refined it for children. Clinical trials are beginning, in which researchers will evaluate which dose is effective and safe in children.

Researchers use detailed mathematical calculations and current adult data to determine safe doses to test in children. The vaccine will not be released to the pediatric community until a safe and effective dose has been determined.

How the dose will be determined

During clinical trials in children, a variety of test doses are tested to determine the most effective dose with the fewest side effects.

Dr. Sharon Nachman , head of the Pediatric Infectious Diseases Division at Stony Brook Children’s Hospital, explains that the researchers use detailed mathematical formulations to determine 2-3 test doses for children, based on the known effective dose in adults.

«For example, if an adult ingested 500 milligrams, you would probably try 125 and 250 and 750 for a child, because you don’t know if the child will metabolize it faster or slower,» he explains.

During these studies, blood samples are taken for researchers to assess how the child’s immune system has responded to each dose, how effective that dose is, and the side effects experienced by the participant.

Dr. Amina Ahmed , Professor of Pediatric Infectious Diseases and Immunology at Atrium Health Levine Children’s Hospital, explains that there is a fine balance in finding an effective dose of vaccine with minimal side effects.

She says: “You balance the lowest dose in terms of side effects with the amount of immune response you build and you … So you have to play with that dose a little bit. You should try different doses methodically. «

When data are available from clinical trials in children aged 12 to 17 years, research will likely be extended to calculate and test doses in younger children and possibly in BOYS . Exactly how soon this will happen is still unknown.

How many doses will the children need

At this stage, the current doses of Pfizer vaccine, pioneered, are likely to mimic the vaccination program for adults. This means that two doses of vaccine will probably be needed three weeks apart. However, tests are still ongoing.

Nachman notes that along with other vaccine studies, such as the HPV vaccine, children need fewer doses than adults to gain immunity. There is a possibility that children may need fewer repeated doses of COVID-19 vaccine, but it is still too early to tell.

Currently, the adult vaccine is 50% effective after one dose and 95% after two doses. Children in clinical trials will be given multiple doses to evaluate this efficacy in the pediatric population.

Nachman says, «They will do exactly the same thing with the children. And eventually they will be able to say that the first dose was so protective. And the second dose was so protective «.

The number of doses they will need when the vaccine is finally released for children will depend on the effectiveness of the doses in the studies.

Ahmed says that even though children need two doses of the Pfizer vaccine, we still don’t know if a booster shot will be needed at a later date.

We know we need two doses for this Pfizer vaccine to be 95% effective. We know. The question is, do we have to repeat the booster dose?


She says: “We know we need two doses for this Pfizer vaccine to be 95% effective. We know. The question is, do we have to repeat the booster dose? «

Because the vaccine has developed so rapidly, it is not yet known whether the body’s immune response will last long or whether, like other vaccines, such as whooping cough, it will need a booster to maintain immunity .

If the test dose is too high, will my child get sick?

The COVID-19 vaccine is not a live vaccine. So if a test dose is higher than needed during the clinical trial, it will not cause a The COVID-19 case .

The body cannot become infected with COVID-19 without the complete viral cell and all its components. The vaccine contains only part of the virus.

Ahmed explains that the spike protein is the part of the virus that our body recognizes as an invading pathogen, causing it to subsequently create antibodies. Therefore, only this portion of the viral cell is used in the vaccine.

Conformable CDC , will take 1 to 2 weeks after the second dose of vaccine for the body to develop a complete immune response. After this time, if we face a real case of the COVID-19 virus, the body will recognize the spike protein from outside the virus and will start fighting the invading cells.

Dose safety

Although the development of COVID-19 vaccine is progressing faster than usual, safety remains paramount. For this reason, the vaccine is not yet available for children.

According to Ahmed, it is realistic to expect some complications in such a new development: “Are things happening? Do people have reactions? Absolute. That’s what’s happening and we’ll find out. But I think everyone is very careful about that, «he said.

Nachman also assures parents that the risk of an incorrect dose is extremely low. She recommends that the child’s weight, liver function, kidney function, blood volume and general health be determined before administration. These details, together with data obtained from adults, are used to calculate safe doses for study in children.

Because these models [matemáticos] They are so sophisticated that they are almost never wrong.


«This happens all the time in medicine, every medicine that has to be administered [a] a child, they practice with mathematical models before reaching the child. » She says. «And when I get to the child, because these models [matemáticos] they are so sophisticated that they are almost never wrong. «

The safety data of vaccine doses to children must be tested before the vaccine can be released for use in the pediatric population.

Ahmed assures parents that while vaccines are developing rapidly, safety is not compromised. She says: “I know people are worried that these vaccines will come out too soon. I will … reiterate that the degree of vigilance here is maximum. «


The dosage examples mentioned in this article are not specific to COVID-19. These are general examples that help explain how doses are chosen for pediatric clinical trials.