Research published in 2021 found that 65% of anti-vaccine posts on social media originated from just 12 individuals.

History tells us the public will tolerate risk of harm from a vaccine if their fear of the disease exceeds their fear of the vaccine.

A 2023 Nature study showed that exposure to diverse content left participants with unchanged core beliefs, suggesting social media alone cannot create hateful viewpoints. However, such platforms allow rhetoric to spread widely, potentially exacerbating geopolitical tensions.

More than 100 videos, found primarily on Instagram and TikTok in August 2025, promoted products related to beauty, wellness and weight loss. While TikTok removed 94% of content violating its policies on AI-generated content, these deepfakes were watched and shared before removal, undermining public trust in medicine.

Before the technology behind vaccinations was discovered, some keen observers of medicine around the globe noticed how previous infections could impact future ones. Learn about the techniques early physicians used before they had vaccines.

Accusations of censorship and bias have led social media companies like Meta and X to scale back or abandon moderation tools—just as foreign propaganda surges. Researchers say their ability to track manipulation online has become severely limited.

For years, Facebook has been accused of taking a too-light approach to content moderation. While it's made strides in recent years, problematic content continues to thrive on the company's platforms.

In 18th- and 19th-century outbreaks, some New England families lost as many as eight children to diphtheria, and fatality rates in hospitals often topped 60%. The invention of antitoxins, penicillin, and vaccines dramatically reduced deaths.

Public health funds and resources that were diverted to COVID-19 response reduced efforts to combat polio and vaccinations for polio and other diseases declined during the pandemic, putting more people at risk for polio.

A measles outbreak in the summer of 2025 ultimately led to more than 900 cases and the deaths of two young children. The highly contagious virus requires vaccination rates near 95% to achieve herd immunity—the Texas outbreak spread through areas of significant mistrust of vaccines, including the area’s Mennonite community.

There are several different types of vaccines. Each type is designed to teach your immune system how to fight off germs—and the serious diseases they cause. This short overview breaks down the differences between the types.

A vaccine is a medical intervention, and as with any medical intervention, may have side effects. This article discusses side effects and adverse events related to vaccination.

The Canadian journal Paediatrics & Child Health issued corrections to 138 case studies published since 2000, acknowledging the cases were entirely fictional—a practice intended to protect patient privacy that was never disclosed to readers. At least 61 of the fabricated reports were cited as fact in other peer-reviewed journals a combined 218 times, including a 2006 Lancet article alleging an infant died from opioid-laced breast milk.

New York Times tech columnist Kevin Roose examines how individuals become radicalized while using platforms like YouTube. Hate crimes that took place before the COVID-19 pandemic inspired the podcast, which looks at online commentators, algorithms, and isolation, and possible explanations for how increased online activity can sometimes lead to violent crime.

Almost all children likely used to contract poliovirus, but scientists suggest that when infants encountered it very early in life—due to poorer conditions and hygiene—they still had some maternal protection from pregnancy or through breastmilk, so the symptoms were more flu-like.

Watch this under-3-minute video explaining how vaccines use the body's immune system to prepare our bodies against viral and bacterial threats to our health.

Research published in 2021 surveyed how more than 100 kids with food allergies were treated by their peers. About one-third of the surveyed kids had their allergies used against them. Bullying tactics included that their allergens were sometimes intentionally put in their food or thrown at them. Parents usually had no idea this bullying was happening.

A whistleblower came forward with internal documents showing employees warned leadership about the company's role in fueling political unrest and misinformation. Systems like XCheck shielded high-profile users like President Donald Trump from normal content rules, often to avoid PR backlash.

A joint investigation by The Examiner and The Washington Post found that food, beverage, and supplement corporations and groups have paid registered dietitians on social media to promote content that goes against decades of scientific evidence on...

Weakened, live virus vaccines—which aren't offered in the US—carry a risk of virus being shed in the stool. Rarely, the shed virus mutates and leads to vaccine-derived polio infections. Most recent polio cases are genetically linked to those vaccines. As shown in this graphic, there are typically hundreds of vaccine-derived polio cases annually.

As viruses mutate and develop, vaccines have to adapt, leading to regular recommended injections like flu shots. Researchers are working to develop universal vaccines that aim to protect against multiple virus variants if not entire virus families. These vaccines work by creating broadly neutralizing antibodies (bnAbs) that target aspects of viruses that don't typically mutate and are integral to the virus' survival.

Though researchers agree that there is a strong genetic component to ASD development, certain environmental factors heighten that risk, with studies suggesting older parents, premature birth, maternal obesity, and air pollution exposure in utero all elevate risks of ASD development. There is no connection between receiving vaccines and ASD development.

Watch experts weigh in on the prevailing business models of vaccine production, including how the Covid-19 pandemic has disrupted the industry for good in this 20-minute video from Financial Times.

Federal guidance currently recommends a two-shot schedule of the MMR vaccine for children in most cases, once at 12 to 15 months and once at 4 to 6 years. (A September 2025 update only called for the elimination of a combined vaccine that included protection against varicella, the MMRV shot.)

Leading up to the 2016 election, misinformation about both Donald Trump, Hillary Clinton, and even Barack Obama flourished on Facebook. In the final stretch leading up to the election, more than one-quarter of Americans visited a fake news site supporting either Trump or Clinton. Many fake news studies have widely different methods of measuring and assessing the impact of fake news, so the actual impact it had in the 2016 election is unclear.

Read up on the basics of vaccinations with this 101 from the World Health Organization, the public health arm of the United Nations.