Meningococcal Vaccine: Protection, Risk, Schedule

Why Childhood Vaccines Are A Public Health Success Story

This article first appeared in The Checkup, MIT Technology Review's weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here.

Later today, around 10 minutes after this email lands in your inbox, I'll be holding my four-year-old daughter tight as she receives her booster dose of the MMR vaccine. This shot should protect her from a trio of nasty infections—infections that can lead to meningitis, blindness, and hearing loss. I feel lucky to be offered it.

This year marks the 50-year anniversary of an ambitious global childhood vaccination program. The Expanded Programme on Immunization was launched by the World Health Organization in 1974 with the goal of getting lifesaving vaccines to all the children on the planet.

Vaccines are estimated to have averted 154 million deaths since the launch of the EPI. That number includes 146 million children under the age of five. Vaccination efforts are estimated to have reduced infant mortality by 40%, and to have contributed an extra 10 billion years of healthy life among the global population.

Childhood vaccination is a success story. But concerns around vaccines endure. Especially, it seems, among the individuals Donald Trump has picked as his choices to lead US health agencies from January. This week, let's take a look at their claims, and where the evidence really stands on childhood vaccines.

WHO, along with health agencies around the world, recommends a suite of vaccinations for babies and young children. Some, such as the BCG vaccine, which offers some protection against tuberculosis, are recommended from birth. Others, like the vaccines for pertussis, diphtheria, tetanus, and whooping cough, which are often administered in a single shot, are introduced at eight weeks. Other vaccinations and booster doses follow.

The idea is to protect babies as soon as possible, says Kaja Abbas of the London School of Hygiene & Tropical Medicine in the UK and Nagasaki University in Japan.

The full vaccine schedule will depend on what infections pose the greatest risks and will vary by country. In the US, the recommended schedule is determined by the Centers for Disease Control and Prevention, and individual states can opt to set vaccine mandates or allow various exemptions.

Some scientists are concerned about how these rules might change in January, when Donald Trump makes his return to the White House. Trump has already listed his picks for top government officials, including those meant to lead the country's health agencies. These individuals must be confirmed by the Senate before they can assume these roles, but it appears that Trump intends to surround himself with vaccine skeptics.

For starters, Trump has selected Robert F. Kennedy Jr. As his pick to lead the Department of Health and Human Services. Kennedy, who has long been a prominent anti-vaxxer, has a track record of spreading false information about vaccines.

In 2005, he published an error-laden article in Salon and Rolling Stone linking thimerosal—an antifungal preservative that was previously used in vaccines but phased out in the US by 2001—to neurological disorders in children. (That article was eventually deleted in 2011. "I regret we didn't move on this more quickly, as evidence continued to emerge debunking the vaccines and autism link," wrote Joan Walsh, Salon's editor at large at the time.)

Kennedy hasn't let up since. In 2015, he made outrageous comments about childhood vaccinations at a screening of a film that linked thimerosal to autism. "They get the shot, that night they have a fever of a hundred and three, they go to sleep, and three months later their brain is gone," Kennedy said, as reported by the Sacramento Bee. "This is a holocaust, what this is doing to our country."

Aaron Siri, the lawyer who has been helping Kennedy pick health officials for the upcoming Trump administration, has petitioned the government to pause the distribution of multiple vaccines and to revoke approval of the polio vaccine entirely. And Dave Weldon, Trump's pick to direct the CDC, also has a history of vaccine skepticism. He has championed the disproven link between thimerosal and autism.

These arguments aren't new. The MMR vaccine in particular has been subject to debate, controversy, and conspiracy theories for decades. All the way back in 1998, a British doctor, Andrew Wakefield, published a paper suggesting a link between the vaccine and autism in children.

The study has since been debunked—multiple times over—and Wakefield was found to have unethically subjected children to invasive and unnecessary procedures. The paper was retracted 12 years after it was published, and the UK's General Medical Council found Wakefield guilty of serious professional misconduct. He was struck off the medical register and is no longer allowed to practice medicine in the UK. (He continues to peddle false information, though, and directed the 2016 film Vaxxed, which Weldon appeared in.)

So it's remarkable that his "study" still seems to be affecting public opinion. A recent Pew Research Center survey suggests that four in 10 US adults worry that "not all vaccines are necessary," and while most Americans think the benefits outweigh any risks, some are still concerned about side effects. Views among Republicans in particular seem to have shifted over the years. In 2019, 82% supported school-based vaccine requirements. That figure dropped to 70% in 2023.

The problem is that we need more than 70% of children to be vaccinated to reach "herd immunity"—the level needed to protect communities. For a super-contagious infection like measles, 95% of the population needs to be vaccinated, according to WHO. "If [coverage drops to] 80%, we should expect outbreaks," says Abbas.

And that's exactly what is happening. In 2023, only 83% of children got their first dose of a measles vaccine through routine health services. Nearly 35 million children are thought to have either partial protection from the disease or none at all. And over the last five years, there have been measles outbreaks in 103 countries.

Polio vaccines—the ones whose approval Siri sought to revoke—have also played a vital role in protecting children, in this case from a devastating infection that can cause paralysis. "People were so afraid of polio in the '30s, '40s, and '50s here in the United States," says William Moss, an epidemiologist at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. "When the trial results of [the first] vaccine were announced in the United States, people were dancing in the streets."

That vaccine was licensed in the US in 1955. By 1994, polio was considered eliminated in North and South America. Today, wild forms of the virus have been eradicated in all but two countries.

But the polio vaccine story is not straightforward. There are two types of polio vaccine: an injected type that includes a "dead" form of the virus, and an oral version that includes "live" virus. This virus can be shed in feces, and in places with poor sanitation, it can spread. It can also undergo genetic changes to create a form of the virus that can cause paralysis. Although this is rare, it does happen—and today there are more cases of vaccine-derived polio than wild-type polio.

It is worth noting that since 2000, more than 10 billion doses of the oral polio vaccine have been administered to almost 3 billion children. It is estimated that more than 13 million cases of polio have been prevented through these efforts. But there have been just under 760 cases of vaccine-derived polio.

We could prevent these cases by switching to the injected vaccine, which wealthy countries have already done. But that's not easy in countries with fewer resources and those trying to reach children in remote rural areas or war zones.

Even the MMR vaccine is not entirely risk-free. Some people will experience minor side effects, and severe allergic reactions, while rare, can occur. And neither vaccine offers 100% protection against disease. No vaccine does. "Even if you vaccinate 100% [of the population], I don't think we'll be able to attain herd immunity for polio," says Abbas. It's important to acknowledge these limitations.

While there are some small risks, though, they are far outweighed by the millions of lives being saved. "[People] often underestimate the risk of the disease and overestimate the risk of the vaccine," says Moss.

In some ways, vaccines have become a victim of their own success. "Most of today's parents fortunately have never seen the tragedy caused by vaccine-preventable diseases such as measles encephalitis, congenital rubella syndrome, and individuals crippled by polio," says Kimberly Thompson, president of Kid Risk, a nonprofit that conducts research on health risks to children. "With some individuals benefiting from the propagation of scary messages about vaccines and the proliferation of social media providing reinforcement, it's no surprise that fears may endure."

"But most Americans recognize the benefits of vaccines and choose to get their children immunized," she adds. Now, that is a sentiment I can relate to.

Read more from MIT Technology Review's archive

A couple of years ago, the polio virus was detected in wastewater in London, where I live. I immediately got my daughter (who was only one year old then!) vaccinated. 

Measles outbreaks continue to spring up in places where vaccination rates drop. Researchers hope that searching for traces of the virus in wastewater could help them develop early warning systems. 

Last year, the researchers whose work paved the way for the development of mRNA vaccines were awarded the Nobel Prize. Now, scientists are hoping to use the same technology to treat and vaccinate against a host of diseases.

Most vaccines work by priming the immune system to respond to a pathogen. Scientists are also working on "inverse vaccines" that teach the immune system to stand down. They might help treat autoimmune disorders.

From around the web

A person in the US is the first in the country to have become severely ill after being infected with the bird flu virus, the US Centers for Disease Control and Prevention shared on December 18. The case was confirmed on December 13. The person was exposed to sick and dead birds in backyard flocks in Louisiana. (CDC) 

Gavin Newsom, the governor of California, declared a state of emergency as the bird flu virus moved from the Central Valley to Southern California dairy herds. Since August, 645 herds have been reported to be infected with the virus. (LA Times)

Pharmacy benefit managers control access to prescription drugs for most Americans. These middlemen were paid billions of dollars by drug companies to allow the free flow of opioids during the US's deadly addiction epidemic, an investigation has revealed. (New York Times)

Weight-loss drugs like Ozempic have emerged as blockbuster medicines over the past couple of years. We're learning that they may have benefits beyond weight loss. Might they also protect organ function or treat kidney disease? (Nature Medicine)

Doctors and scientists have been attempting head transplants on animals for decades. Can they do it in people? Watch this delightful cartoon to learn more about the early head transplant attempts. (Aeon)

Children Flu Deaths Trending Up As Parents Reject Long-Held Vaccination Guidance

Americans are increasingly deciding not to get their children vaccinated, even after the 2023 flu season saw a record number of children die from the virus.

Data released by the Centers for Disease Control and Prevention show that from the start of the flu season until the first week of December this year, nearly 143 million flu vaccines were distributed. During that same time period in 2023, 153.6 million vaccines were distributed, down from a high of 171 million vaccines distributed during the Covid pandemic in 2021.

The centers also report that fewer children are being vaccinated. As of December 14 this year, 42 percent of children aged six months to 17 years had received a vaccine, down from 44.7 percent in the previous year and from 53.7 percent during the same period in the 2019-2020 season, prior to the pandemic.

The drop in the number of Americans getting vaccinated comes as polls have found that more people say they believe vaccines are more dangerous than the disease they aim to prevent. A Gallup poll in 2019 found 11 percent of Americans said vaccines were more dangerous than the disease. In 2024, that number jumped to 20 percent. 

Fewer Americans are also saying that they think it is important for parents to have their children vaccinated. In 2001, 94 percent of respondents told Gallup that it was "extremely" or "very" important for children to be vaccinated. In 2024, 69 percent of Americans said the same. 

That sentiment is divided by political party affiliation. In 2002, 62 percent of Republicans said it was "extremely" or "very" important for children to be vaccinated. In 2024, Republican support dropped to 26 percent. In 2002, 66 percent of Democrats said childhood vaccinations were important while 63 percent agreed in 2024. 

The reluctance follows much skepticism over the value of the Covid shots that Americans were mostly mandated to get, even as children were determined to be less reactive to the virus than older Americans. 

Days before the 2024 election, Vice President-elect Vance raised concerns about the side effects of vaccines, telling podcaster Joe Rogan about his own experience getting the Covid vaccination. 

"We're not even allowed to talk about the fact that I was as sick as I've ever been for two days, and the worst Covid experience I had was like a sinus infection. I'm not really willing to trade that," he said. 

In September, Florida's surgeon general, Joseph Ladapo, discouraged the use of mRNA Covid vaccines for adults over 65 as he raised concerns about their safety. Meanwhile, a spokeswoman for the Louisiana Department of Health, Emma Herrock, said earlier this month that the department is "shifting away from one-size-fits-all paternalistic guidance" of recommending Covid or flu vaccines. 

While the percentage of parents getting their children vaccinated for the flu has decreased, the number of children who died from influenza ticked up to 200 last year, exceeding the 199 deaths recorded in 2019-2020. So far this flu season, 23,000 people of all ages have been hospitalized because of the flu.

Skepticism about vaccine safety is not solely focused on seasonal flu vaccines but also on childhood vaccinations for measles, mumps, and rubella. In 2015, then-candidate Trump publicly discussed what has been largely considered a fringe conspiracy theory — that combination vaccines for children may be responsible for autism. 

"Just the other day, two years old, two and a half years old, a child, a beautiful child, went to have the vaccine and came back, and a week later got a tremendous fever, got very, very sick, now is autistic," Trump said during a primary debate. 

Scientists have repeatedly tried to tamp down such theories, saying the scientific link between vaccines and autism has been thoroughly debunked. They point to other explanations for the uptick in the diagnosis over the last two decades, including changes in the screening process and an expansion of the definition of autism. 

However, with Trump tapping vaccine opponent Robert F. Kennedy Jr. To lead the Department of Health and Human Services, more debate lies ahead. For his part, Trump has not committed to eliminating childhood vaccines, saying he would look into ending vaccination programs if "I think they are not beneficial."

Childhood Vaccines Are Safe And Lifesaving. Reject The Quackery Of Anti-vaxxers Such As RFK Jr. [editorial]

THE ISSUE

On a stop in Lancaster city Wednesday, "Gov. Josh Shapiro said Pennsylvania intends to follow through with its $21 million commitment to the expansion of the GSK vaccine plant near Marietta despite the vaccine skepticism of President-elect Donald Trump's nominee to run the federal Health and Human Services Department," LNPLancasterOnline's Lisa Scheid reported. If confirmed, Robert F. Kennedy Jr. Would lead the $1.7 trillion department, which regulates food and drugs, funds research and establishes vaccine recommendations.

We'd like all of you reading this to be alive and healthy for not only this holiday season but future ones.

So we implore you to tune out the disinformation and misinformation about vaccination and talk to your health care provider about getting the vaccines you need.

The health of Lancaster County residents is our only interest here.

We have no financial stake in the British multinational pharmaceutical and biotechnology company GSK's vaccine packaging facility in East Donegal Township. As LNPLancasterOnline's Scheid reported, "GSK plans to invest $800 million over the next four years in an expansion project that would add research and manufacturing capabilities along with 200 jobs." It will be aided by $21 million in state grants that the governor announced in October, as well as local tax incentives.

We are pleased by Shapiro's intention to follow through on those grants because this project should be a boon to Lancaster County's economy. Two-hundred jobs are nothing to sneeze at.

And speaking of sneezing, you may be doing a whole lot less of it if you're vaccinated against COVID-19, influenza and, in the case of older readers, RSV. Don't forgo vaccines just because of some nonsense you heard from a know-nothing anti-vaxxer on social media, a podcast or cable news network.

Vaccines are a modern miracle. They have transformed the landscape of childhood, making it possible for kids to grow up healthy and strong and unburdened by the diseases — such as polio and measles — that had sickened, disabled and killed children of previous generations.

Unfortunately, as KFF (formerly the Kaiser Family Foundation) recently reported, routine vaccination rates for kindergarten children continue to decline in the United States, while exemptions from school vaccination requirements — particularly nonmedical exemptions — have increased.

These trends, KFF noted, began with the COVID-19 pandemic "and appear to be related to increasing vaccine hesitancy, fueled in part by vaccine misinformation."

Because Lancaster County generally has lagged behind other Pennsylvania counties in child immunizations, we have repeatedly implored state lawmakers to do away with the exemptions that make opting out of school-required immunization far too easy. Vague "philosophical exemptions," in particular, have been abused by parents to get their children exempted from required childhood vaccines that are meant to keep their kids — and their kids' classmates — healthy.

While some MAGA groups have embraced the anti-vaccination movement, they're not alone: Wealthy liberals and working-class libertarians are also part of this dangerous alliance. The glue that binds them together is a mix of junk science, quackery and selfishness.

Robert F. Kennedy Jr. Has been among the most prominent of the anti-vaxxers and he has, in Trump, support for his fringe views.

Kennedy has no medical or public health training, but he still cavalierly fearmongers about vaccination and fluoridation of water. He also promotes the supposed health benefits of unpasteurized milk — despite the fact that avian flu has been found in raw milk, and the consumption of raw milk can cause life-threatening bacterial infections.

Kennedy's own family members have disavowed his bizarre and unscientific views.

In a Nov. 24 LNPLancasterOnline column, Dr. Jeffrey T. Kirchner dissected Kennedy's spurious claims and concluded that he is unqualified to lead the Department of Health and Human Services. Kirchner — an expert in HIV care, the medical director of Caring Communities and the former medical director of Lancaster General Health Physicians Comprehensive Care — has had decades of experience in dealing with infectious disease. He is just one of countless medical experts who have concluded that having the untrained RFK Jr. As the nation's top health official is a worrisome prospect.

Kennedy's most egregious error has been to promote a false — and thoroughly debunked — link between childhood vaccines and autism.

In 2018, two nurses — later imprisoned for negligence — in the South Pacific island nation of Samoa administered doses of the measles, mumps and rubella vaccine that had been wrongly mixed with a liquid muscle relaxant instead of water, and two infants tragically died.

The infants died not because of the MMR vaccine — which is both safe and lifesaving — but because of human error.

In 2019, RFK Jr. Visited Samoa, where he shamefully seized on the infants' deaths to gin up fears about the MMR vaccine, and immunization rates dropped.

The consequences were terrible: Vaccine hesitancy led to an outbreak of measles on Samoa that infected 5,700 people and killed 83, most of them young children. As the medical journal The Lancet noted, "Samoa's Ministry of Health cited Kennedy's visit and his rhetoric as exacerbating vaccine hesitancy at a crucial moment."

RFK Jr. Should be a pariah, not a Cabinet member. We fear the damage he could do if confirmed by the U.S. Senate.

"The litany of things that will start to topple is profound," James Hodge, a public health law expert at Arizona State University's Sandra Day O'Connor College of Law, told NPR earlier this month. "We're going to experience a seminal change in vaccine law and policy."

Delaying Food and Drug Administration vaccine approvals and abolishing the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices are just a couple of the ways RFK Jr. Could impede vaccine distribution.

And what might happen if avian flu becomes a pandemic? The mind reels.

We worry, too, about the coming onslaught of vaccine misinformation and disinformation from an administration that prefers conspiracy theories to proven science.

We learned from media reports in recent days that a key legal adviser to Kennedy petitioned federal regulators to revoke approval for the polio vaccine. The New York Times reported that adviser has joined Kennedy in interviews in asking candidates for top health jobs for their views on vaccines.

The cynical response to this has been to joke about making polio great again. But there's nothing funny about polio. There's nothing funny about any of the vaccine-preventable diseases.

Please don't buy misinformation and disinformation from anti-vaxxers. Consult a trusted physician instead. Doctors want you to be healthy. We do, too.

Success! An email has been sent to with a link to confirm list signup.

Error! There was an error processing your request.

---