Children make up about a quarter of the U.S. population. Many experts say it’s important for them to get vaccinated against COVID-19 not only to protect them from the coronavirus, but also to help communities achieve herd immunity, which is when enough people have become immune to the virus that it’s unlikely for it to spread.
“Could you eradicate COVID without vaccinating children? I think it would be really hard until we vaccinate kids,” says Dr. Kawsar Talaat, an assistant professor in the department of international health at Johns Hopkins Bloomberg School of Public Health, whose research focuses on early-stage vaccine trials.
As of April 8, more than 3.5 million children in the U.S. have tested positive for COVID-19 since the onset of the pandemic, representing 13.5% of all of the nation’s diagnosed infections, according to the latest report from the American Academy of Pediatrics and the Children’s Hospital Association.
While researchers are closely watching the behavior of new COVID-19 variants in children, so far the coronavirus has posed the greatest threat to adults. Until recently, the drug makers’ main focus has been developing COVID-19 vaccines for adults, but that’s changing as several COVID-19 vaccine trials for children are underway.
Children have made up less than 300 of more than 560,000 COVID-19 deaths in the U.S., according to the AAP report. Between 0.1% and 1.9% of all child COVID-19 cases in the U.S. resulted in hospitalization. (Hospitalization rates in adults vary by age. Adults older than 65 have had the highest rates of hospitalizations from COVID, ranging from a high of 70 per 100,000 people to less than 20 per 100,000 in April, according to the Centers for Disease Control and Prevention.)
Because COVID-19 does not pose as great a risk to children based on available data so far, the potential benefits of a vaccine have to far outweigh its potential risks, such as severe reactions.
“So the issue becomes, do we want even more safety data for COVID vaccines in children than we need in adults and is there the same level of emergency?” says Dr. H. Cody Meissner, chief of the division of pediatric infectious disease at Tufts Children’s Hospital and a professor of pediatrics at Tufts University School of Medicine, who’s a member of the Advisory Committee on Immunization Practices and a previous chair of the National Vaccine Injury Compensation Program. “And I think different people will answer that in different ways.”
The American Academy of Pediatrics recommends all eligible adults and teens 16 years and older get the COVID-19 vaccine as soon as it’s available to them. (Currently, the Pfizer vaccine is cleared for ages 16 years and older.) It also advocates for the inclusion of children of all ages in clinical trials.
“Once approved, vaccine distribution and access should be supported for all children and adolescents, with particular attention to those disproportionately affected by the pandemic,” according to the Academy’s interim guidance for COVID-19 vaccination.
The COVID-19 vaccines for children that are currently being tested aren’t quite comparable to other childhood vaccines. For one, a pediatric vaccine has never been developed and tested so quickly and to potentially become authorized for emergency use.
Also, recent pediatric vaccines were mainly developed for and tested in children or adolescents.
For instance, the rotavirus vaccine, first licensed in the U.S. in 1998, was developed for infants and young children to prevent severe diarrhea, fever and vomiting caused by the rotavirus disease. The HPV vaccine, which protects against different types of cancer caused by the human papillomavirus, was developed in 2006 for adolescents and later expanded to adults.
“The flu vaccine is also different, because it’s been around a really long time,” says Talaat. “But we didn’t start vaccinating children [against the flu] until relatively recently, so I don’t know that there’s really an analogous vaccine that’s widely used and widely distributed.”
She says the current COVID-19 vaccine clinical trials for children are being performed carefully and methodically. But she advises reporters to pay attention to trial design and how researchers are monitoring vaccine safety and outcomes.
The size of the clinical trials is also important to note. Adverse vaccine reactions are rare, so a smaller study is less likely to capture those rare events, Meissner says.
“You can say that [the vaccine] was safe in that study. That’s all you can say,” says Meissner.
The latest on COVID-19 vaccine trials for children
- Pfizer began testing its vaccine in children ages 6 months to 12 years in late March. The clinical trial will evaluate the safety, tolerability and the immune response to the two-dose vaccine. On March 31, the company also announced that its vaccine is 100% effective in adolescents ages 12 to 15 years.
- Moderna, another manufacturer, also is testing its two-dose vaccine on children ages 6 months to 12 years. It also has been testing the vaccine on older children and young adults, ages 12 to 18 years.
- Johnson & Johnson announced April 2 that it has expanded its COVID-19 vaccine trial to include adolescents ages 12 to 17 years.
- AstraZeneca began testing its vaccine in children ages 6 to 17 years, but the trial was paused April 6 while United Kingdom regulators investigated rare cases of blood clots in those who received its vaccine.
The rollout of COVID-19 vaccines for children is an important story for local, regional, national and international newsrooms alike. To help journalists with their reporting, we’ve gathered several studies and academic commentaries that provide perspective and background on vaccines for children.
The big picture
What are the key challenges and knowledge gaps in developing COVID-19 vaccines for children? The commentary “SARS-CoV-2 Vaccine Testing and Trials in the Pediatric Population: Biologic, Ethical, Research, and Implementation Challenges,” published in February in Pediatric Research, provides an overview of several issues, including rationale for vaccines in children, ethical concerns, unique considerations for children with special needs, health inequities and vaccine hesitancy.
The commentary, based on input from a range of experts such as frontline health care providers, ethicists researchers and community representatives, lists several reasons children should be vaccinated against COVID-19. Among the reasons: children with COVID-19 are hospitalized at a rate similar to children with the flu – and the flu vaccine reduces the risk of flu-associated death by 50% to 66%, the authors write.
They also discuss the potential impact of childhood obesity on kids’ responsiveness to COVID-19 vaccines.
“Tracking environmental factors like nutrition and physical activity may be useful in assessing the effectiveness of any COVID-19 vaccine given to children and adolescents,” the 14 authors write.
Addressing vaccine hesitancy is another challenge. One in five children in the U.S. have a parent who is vaccine hesitant, according to “Parental Vaccine Hesitancy and Childhood Influenza Vaccination,” an academic paper published in Pediatrics in December.
The authors suggest rolling out the vaccine in phases.
“A phased vaccination program for children that starts with 12-17 years and moves to younger children once we have clearer safety and efficacy data in young people might reduce vaccine resistance or hesitancy as well as being consistent with a limited vaccine supply and the need to prioritize its use,” the authors write.
In Table 1 of the commentary, the authors list several unanswered questions to highlight knowledge gaps and research opportunities about the coronavirus vaccine in children. Journalists can pose these questions to expert sources or use them as a guide for story ideas. The list includes questions such as “What factors represent true barriers to vaccination in various ethnic groups and what strategies can be developed to overcome them?” and “Is evidence for vaccine hesitancy from the influenza and HPV vaccines applicable to COVID-19?”
Vaccine mandate for children
It’s too early to tell whether there will be a COVID-19 vaccine mandate for children or adults, but the issue already is a subject of debate among researchers.
In a perspective paper, “Vaccinating Children Against Covid-19 — The Lessons of Measles,” published in February in The New England Journal of Medicine, renowned pediatrician Dr. Perri Klass and Dr. Adam J. Ratner, a pediatric infectious disease specialist, write that protecting children against COVID-19 is “both an ethical obligation and a practical necessity. We need data from pediatric trials to reassure parents about the safety and wisdom of this approach.”
They recount the history of the measles vaccine, including the challenges of convincing parents to get their children vaccinated and the success of public health campaigns and school vaccination mandates. They also discuss the false information and propaganda that have discouraged vaccination.
“The measles vaccine story reminds us that we have an obligation to provide equitable access and clear information; that coordinated, federally supported efforts are essential; and that doubt, distrust, and disinformation can undermine safe, effective vaccines and worthy public health initiatives,” they write.
They add: “We need to consider lessons from recent measles epidemics — not only about the power of legislative mandates, but also about their potential for sowing distrust if delivered without careful, sensitive, accurate public health messaging.”
In the viewpoint article, “Should We Mandate a COVID-19 Vaccine for Children?” published in JAMA Pediatrics last September, the authors suggest nine standard criteria to help determine whether a COVID-19 vaccine should be required. They highlight the first criterion as the most important: “There must be evidence that a COVID-19 vaccine is safe for children with an acceptable level of risk,” write Drs. Douglas Opel, Douglas Diekema and Lainie Friedman Ross.
“It would be a mistake to consider making a COVID-19 vaccine mandatory without these data,” they write. “Vaccine safety is fundamental to maintaining the public’s trust in vaccines, and skirting this safety criterion could have far-reaching consequences.”
Meanwhile, in the editorial “SARS-CoV-2 Vaccination for Children — An Open Issue,” published last month in Pediatric Reports, the authors argue against a COVID-19 vaccine mandate, pointing out that the COVID-19 infection is far less severe in children than adults.
History of vaccines
The following studies are helpful for journalists who are new to covering vaccines or want to give their audience background on the history of children’s vaccines.
In the perspective paper, “On the Shoulders of Giants — From Jenner’s Cowpox to mRNA Covid Vaccines,” published last month in The New England Journal of Medicine, Drs. Paul Offit and Angela Desmond summarize the major advances in vaccine development since 1796 when the smallpox vaccine was discovered.
They write that the COVID-19 pandemic will be an important test of whether new vaccine technologies such as mRNA vaccines will fulfill their promise of creating safe, effective and scalable vaccines more quickly than the existing methods.
“If they pass this test, the next task will be to accomplish equitable, efficient vaccine distribution — which would represent an even greater achievement,” they write.
The academic paper, “Childhood Vaccine Development: An Overview,” was published in Pediatric Research in 2004, but it provides solid background information on vaccine development by decade, starting from 1890.
Other childhood vaccines under development
The human respiratory syncytial virus, or RSV, which causes upper respiratory tract infection, is a major threat to very young children and the elderly, resulting in 3.2 million hospital admissions and 118,000 deaths in infants globally each year, according to the authors of “Vaccines Against Human Respiratory Syncytial Virus in Clinical Trials, Where Are We Now?” In the U.S., RSV infection results in about 177,000 hospitalizations and 14,000 deaths each year, the authors write in the paper, published in October 2019 in the journal Expert Review of Vaccines.
Developing vaccines against RSV has faced challenges, including difficult target populations and a virus that doesn’t induce a long-lasting immune response, which the authors review. They also explain the different types of RSV vaccines under development.
A newly published systematic review of 38 studies on RSV vaccine clinical trials discusses the safety data of ongoing clinical trials and the risk of RSV re-infection among those who were vaccinated as part of the trials. That paper, “The Immunogenicity and Safety of Respiratory Syncytial Virus Vaccines in Development: A Systematic Review,” appears in the March 2021 edition of Influenza and Other Respiratory Viruses.