Even though parents in the US wrestle with difficult questions about vaccinating their children against the coronavirus, families in other countries have been offered a novel option: giving children only one dose of the vaccine.
Officials in Hong Kong, as well as the UK, Norway and other countries, have recommended a single dose of the Pfizer BioNTech vaccine for children 12 years and older – partial protection from the virus but without the potential harm sometimes seen after two doses. On Wednesday, Sweden and Denmark joined the ranks, announcing that teenagers should only receive one shot of the Moderna vaccine.
Health authorities in these countries are particularly concerned about the increasing data suggesting that myocarditis, an inflammation of the heart, is more common than expected in adolescents and young adults after vaccination.
The risk remains very low and only becomes significant after the second dose of an mRNA vaccine. But the numbers have changed the risk-benefit calculation in countries where new infections are usually lower than in the United States.
Advisors to the Centers for Disease Control and Prevention reviewed the myocarditis data in June and unanimously voted to recommend the vaccine for children 12 years and older, as the benefits far outweigh the risk.
Agency research has estimated that for every million boys aged 12-17 years vaccinated in the United States, the vaccinations could cause a maximum of 70 cases of myocarditis, but they would prevent 5,700 infections, 215 hospitalizations, and two deaths. Studies have also shown that the risk of heart problems after Covid-19 is significantly higher than after a vaccination.
Myocarditis was one of the concerns that led the Food and Drug Administration to urge vaccine makers this summer to increase the number of children in clinical trials. The subject is likely to be the focus of intense discussion when the agency’s advisors meet next week to review evidence of vaccinations in children ages 5-11.
The latest analysis, published Wednesday in the New England Journal of Medicine, found that post-vaccination post-vaccination myocarditis in Israel was highest in men aged 16 to 29. About 11 out of 100,000 men in this age group developed the disease a few days after vaccination, a rate higher than most previous estimates. (The risk was negligible in women of all ages.)
Of the 54 cases identified in the study, one was severe enough to require ventilation. Another patient with a history of heart disease died shortly after leaving the hospital of unknown cause.
Of the 14 patients in the new study who had heart abnormalities when they were admitted to the hospital, 10 still had signs of problems when they were discharged. When patients were re-examined a few weeks later, all five patients for whom results were available appeared to have fully recovered.
A second study, also published in the journal, found that boys between the ages of 16 and 19 had the highest incidence of myocarditis after the second dose – nine times as high as compared to unvaccinated boys of the same age at the same time.
Health authorities in other countries plan to rethink the one-dose strategy as more safety information becomes available and they may choose to move on to second shots. But the possibility of postponing the second vaccination hasn’t received enough attention in the United States, said Dr. Walid Gellad, a drug safety expert at the University of Pittsburgh.
“In the US, people didn’t want to talk about it for some unclear reason,” said Dr. Gellad. “Reluctant parents may appreciate that the risk of side effects is actually much lower with one dose than with two doses.”
Serious side effects have been seen mostly in boys, so the dosage calculation should be different for boys and girls, he added.
It’s too early to know if myocarditis could permanently weaken some people’s hearts after vaccination, said Dr. Jeremy Brown, a respiratory specialist at University College London and a member of the UK Vaccination Advisory Group.
“That makes it very difficult for us to make the absolute statement that it is perfectly safe to give this vaccine,” said Dr. Brown. “We need a feel for what the long-term effects of myocarditis could be.”
The urgency of fully vaccinating children with two doses needs to be weighed up for the specific situation in each country, experts said. In the UK, high vaccination rates among older and high-risk adults have helped keep hospitals largely free from patients seriously ill with Covid-19.
“The chance of developing severe Covid in a healthy 12 to 15-year-old is almost negligible,” said Dr. Brown. “On the other hand, you have to make sure that the vaccine you are giving is completely safe.”
Some experts have argued that immunizing children would help cut chains of transmission and contain the virus. But immunizing children to protect others – when there might be even the smallest risk to the recipient – is unjustifiable, said Dr. Brown.
“You don’t vaccinate a 15-year-old to prevent him from infecting other adults – that’s morally and ethically wrong,” he said.
In Hong Kong, the case for double dosing young people is even weaker than in the UK, said Benjamin Cowling, an epidemiologist at the University of Hong Kong.
Hong Kong has recorded just 213 deaths and just over 12,000 cases of Covid-19 since the pandemic began, with fewer than 10 cases a day since April. So the risk of myocarditis, however rare, outweighs the benefits of having adolescents fully vaccinated, said Dr. Cowling.
Clinical trials of the vaccine in children are not large enough to detect rare side effects like myocarditis, he added. “You only see it when it comes down to the population level, and then it’s too late.” Whether children should be given a second dose “requires careful consideration”.
But the United States is not in the same position as other countries, noted Dr. Jeffrey Duchin, an infectious disease doctor and a non-voting member of the CDC’s Vaccine Advisory Group.
The state of vaccine mandates in the United States
- Vaccination rules. On August 23, the FDA granted Pfizer-BioNTech’s coronavirus vaccine full approval for people aged 16 and over, paving the way for mandates in both the public and private sectors. Such mandates are legally permissible and have been confirmed in legal challenges.
- College and Universities. More than 400 colleges and universities require a vaccination against Covid-19. Almost all of them are in states that voted for President Biden.
- Schools. California became the first state to enact a vaccine mandate for all educators and announced plans to add the Covid-19 vaccine as a requirement for school attendance, which could begin as early as next fall. Los Angeles already has a public school vaccination mandate for students 12 and older, beginning November 21. New York City’s mandate for teachers and staff, which went into effect Oct. 4th after delays due to legal challenges, appears to have spurred thousands of last-minute recordings.
- Hospitals and medical centers. Many hospitals and major health systems require their employees to be vaccinated. Health worker mandates in California and New York state appear to have forced thousands of objecters to be injected.
- Indoor activities. New York City requires workers and customers to provide proof of at least one dose of the Covid-19 for indoor dining, gyms, entertainment and performances. Beginning November 4th, Los Angeles will require most people to demonstrate a full vaccination in order to enter a number of indoor businesses, including restaurants, gyms, museums, cinemas, and salons, under one of the strictest vaccination regulations in the country.
- At the federal level. On the 9th of September President Biden announced a vaccination mandate for the vast majority of federal employees. This mandate applies to employees of the executive branch, including the White House and all federal agencies and members of the armed forces.
- In the private sector. Mr Biden has ordered that all companies with more than 100 employees mandate vaccinations or weekly tests to drive new company vaccination policies. Some companies, such as United Airlines and Tyson Foods, had mandates prior to Mr. Biden’s announcement.
About 2,000 Americans die every day, and hospitals in many parts of the country are still overcrowded. “We have had a significant impact on our pediatric population,” said Dr. Duchin.
Almost 900,000 children have been hospitalized with Covid-19 since the pandemic began, and around 520 have died. Some children have developed what is called long Covid-19, where symptoms can last for months, and more than 4,000 children have been diagnosed with a dangerous condition called multisystem inflammatory syndrome.
“All the data we have so far suggests that the disease itself is significantly worse than the side effects of the vaccine,” said Dr. Duchin. With all of this in mind, low risk of myocarditis is well worth it, he said, and two doses are justified.
Dr. Duchin said he also had concerns that a dose of the vaccine might not protect children from infection or disease – at least not for long. “I just haven’t seen any data to suggest that one dose would provide long-lasting and high levels of protection,” he said.
All of these concerns, as well as myocarditis data, should inform a national conversation about how useful it is to offer teenagers one dose versus two syringes, some experts said.
“There has been too little discussion about the possible harm of vaccinations because everyone is very, very sensitive to hesitation and anti-vaccination campaigns do not want to give fuel,” said Dr. Cowling.
In the United States in particular, many public health experts have been reluctant to raise concerns about the vaccines, said Dr. Gellad: “Nobody wants to raise doubts that children should be vaccinated. But I think there are ways to talk about it that will appeal to hesitant people. “
Kristina Rogers, a 51-year-old mother of two in Oklahoma, said she would welcome the option of giving her 12-year-old daughter just one dose of the vaccine.
Ms. Rogers, who is fully immunized, worries that not enough is known about the long-term effects of vaccines in children and would like a more open discussion.
Ms. Rogers has diabetes and developed chronic kidney disease after a severe attack with Covid last year. She lost her brother-in-law to Covid a year ago.
But the two doses of the vaccine also made her tired and tired, and she feared the vaccinations might prove to be too much for her children. They wear masks to school and wash their hands regularly, but Mrs. Rogers and her husband are not ready to vaccinate them yet.
“The last thing you want to do is mess with your ticker, man – that’s what makes you go,” she said. “I would be more ready for one dose if that were an option.”