Q&A about COVID-19 vaccines

Frequently asked questions about COVID-19 vaccine for children

UNICEF Viet Nam
Do parents know how Covid-19 vaccines for children are researched, developed and tested?
UNICEF Viet Nam\Truong Viet Hung
08 April 2022

1. What is WHO’s official position about COVID-19 vaccines for children in Vietnam?

WHO recommends that countries with moderate-to-high rates of primary series coverage in higher priority groups such as health workers, those with underlying medical conditions and older persons may consider expanding

its vaccination target towards next tiers such as adolescents and children.

Viet Nam has already achieved high vaccination rates in high-priority groups and adolescents. Also, the booster dose coverage is progressing very well.

Hence, now is the right time for Viet Nam to consider vaccination for children, including those who are 5 to 11 years old. 

WHO also advocates for Viet Nam to continue in its excellent efforts in vaccinating the unreached populations and those in remote areas. 

2. How have COVID-19 vaccines for children been researched and tested?

All vaccines go through extensive and rigorous testing and evaluation processes for efficacy, quality and safety, through multiple steps of assessments including pre-clinical assessment and three phases of clinical trials.

The national regulatory authorities review information submitted by the manufacturers on the vaccine, in order to decide whether to authorize the vaccine for use or not.

As the elderly group and adults with underlying medical conditions are high risk groups of COVID-19, the vaccine products were first researched and tested for the adult population.

After obtaining good performance and safety data in the real world from these groups, the vaccine developers have gradually expanded their target population to the younger age group.

Through these stepwise processes, the manufacturers have generated data from the younger population.

The national regulatory authorities then reviewed new data and updated the authorization to use the vaccines in young children.

3. Is the COVID-19 vaccine safe and necessary for children?

Vaccinating children can help reduce the spread of the virus, especially among those who are at higher risk. Most children are at low risk of serious disease and vaccinating them would be primarily about reducing transmission. WHO recommends that children aged 5 years old and above and with comorbidities that put them at significant risk of severe COVID-19 should be offered vaccination alongside other high-risk groups.

4. Are children not at risk of COVID-19?

Children and adolescents tend to experience a milder COVID-19 disease compared to adults, though there are other risks that we need to consider when a child gets sick with COVID-19 such as multisystem inflammatory syndrome in children (MIS-C), a serious condition that can prolong a child’s recovery from COVID-19.

5. How is the COVID-19 vaccine safely transported and stored?

Vaccines against Covid-19 are transported in a cold chain. Each stage in the transportation including airplanes, trucks, refrigerators, coolers, which help preserving vaccines in the best condition.

6. How do COVID-19 vaccines work?

Vaccines work by mimicking an infectious agent – viruses, bacteria or other microorganisms that can cause a disease. This ‘teaches’ our immune system to rapidly and effectively respond against it. 

Traditionally, vaccines have done this by introducing a weakened form of an infectious agent that allows our immune system to build a memory of it. This way, our immune system can quickly recognize and fight it before it makes us ill. That’s how some of the COVID-19 vaccines have been designed.

Other COVID-19 vaccines have been developed using new approaches, which are called messenger RNA, or mRNA, vaccines. Instead of introducing antigens (a substance that causes your immune system to produce antibodies), mRNA vaccines give our body the genetic code it needs to allow our immune system to produce the antigen itself. mRNA vaccine technology has been studied for several decades. They contain no live virus and do not interfere with human DNA.


For more information on how vaccines work, please visit WHO.

7. How were COVID-19 vaccines developed so quickly?

Scientists were able to develop safe effective vaccines in a relatively short amount of time due to a combination of factors that allowed them to scale up research and production without compromising safety: 

Because of the global pandemic, there was a larger sample size to study and tens of thousands of volunteers stepped forward 

Advancements in technology (like mRNA vaccines) that were years in the making 

Governments and other bodies came together to remove the obstacle of funding research and development 

Manufacturing of the vaccines occurred in parallel to the clinical trials to speed up production 

Though they were developed quickly, all COVID-19 vaccines approved for use by the WHO are safe and effective.

8. Is it true that COVID-19 vaccines cause acute hepatitis among children?

Before being rolled out to a wider population, COVID-19 vaccines have passed rigorous testing to ensure their safety and efficacy.

It is NOT TRUE that COVID-19 vaccines cause acute hepatitis among children. Based on current evidence, there is no link between COVID-19 vaccination and pediatric hepatitis cases. A vast majority of affected children did not actually receive the COVID-19 vaccine.   

COVID-19 vaccines are safe for children and are important in keeping them protected from severe illness and death due to COVID-19.