Correcting this week’s misinformation: week of October 15, 2026

A new Rolling Stone article has ethicists and scientists concerned because it says that CDC will conduct a vaccine study in Guinea-Bissau where 7,000 newborn babies will receive a Hepatitis B vaccine at birth and 7,000 will not.

• Guinea-Bissau’s government says it has not approved the study.
• Hepatitis B at birth can lead to lifelong infection and liver cancer.
• Vaccination at birth helps prevent infection, raising ethical concerns about delaying it.

Hepatitis B is a virus that can cause lasting liver damage. A mother with the infection can pass it to her baby during birth. Vaccination at birth helps prevent this.

Hepatitis B is common in Guinea-Bissau. One study in Bissau, the country’s capital, found signs of a current infection in about 19% of adults—nearly 1 in 5. This finding came from adults in the study, so it does not tell us the exact rate across the whole country.

Some mothers have a very high chance of passing the virus to their babies. Without steps to prevent infection, that risk can be 70% to 90% when the mother has a blood marker showing that the virus can spread easily. This high risk does not apply to every mother with hepatitis B.

Infection at birth often lasts for life. About 9 in 10 babies who get hepatitis B during birth develop a chronic infection. “Chronic” means the infection lasts a long time and may never go away.

The damage may appear years later. Chronic hepatitis B can cause cirrhosis, which is serious scarring of the liver, or liver cancer. People infected at birth who receive no medical care or treatment may have up to a 1 in 4 chance of developing liver cancer during their lifetime.

Vaccination starting at birth can prevent infection. For babies born to mothers with hepatitis B, vaccination prevents about 75% of infections passed during birth. Protection rises to about 94% when babies also get hepatitis B immune globulin, or HBIG. This extra shot contains antibodies—proteins that fight the virus right away. Babies still need the rest of their vaccine doses.

The ethical concern is that delaying a proven vaccine could leave babies exposed to a serious infection. The World Health Organization says withholding the birth dose in this study could cause lasting, preventable harm.

In a rebuttal to us, Karl Jablonowski’s claims that oral vitamin K is a safer option for newborn babies because the injection was never tested to see if it causes cancer, genetic issues, or fertility problems.

• Vitamin K is not a vaccine; it helps blood clot and stop bleeding.
• One label section does not tell the full safety story about vitamin K or its ingredients.
• The vitamin K shot protects babies from serious bleeding better than oral vitamin K.

Neither Dr. Paul Offit nor Dr. Stanley Plotkin helps write the “Just the Facts” newsletter. They are both wonderful people, and we will absolutely defend them.

Jablonowski also points to Section 13.1 of the vitamin K shot’s package insert, which gives information about the medicine. This section says certain studies on cancer, damage to genes, and problems having children were not done. It appears under “Nonclinical Toxicology,” which covers safety testing outside of humans, such as animal and laboratory studies. It is not a summary of all safety research in people.

That distinction matters. The absence of these tests does not, by itself, show that the shot causes these harms or that its safety has never been studied. Vaccines and their ingredients are checked for these possible safety risks.

The vitamin K shot is not a vaccine, but its safety also depends on its ingredients and the amounts used. When reviewing safety, experts consider whether a product could cause cancer, damage genes, or affect a person’s ability to have children. 

Vitamin K helps blood clot so bleeding can stop. Babies are born with low levels of vitamin K, which can put them at risk for dangerous bleeding, including in the brain. The Canadian Paediatric Society recommends the shot because it offers better protection than vitamin K given by mouth.

Jablonowski objects to being called an anti-vaccine activist. We use that term because he says he has never seen a safe vaccine. In our view, that statement argues against the use of vaccines.

A new study shows just the opposite! Women who were vaccinated against HPV were less likely to have babies born early than full term.

• A study of nearly 625,000 births linked HPV vaccination before pregnancy to fewer early births.
• Vaccinated women also had lower odds of having babies much smaller than expected.
• The findings suggest possible pregnancy benefits, but do not prove the vaccine caused them.

HPV is a common virus that can cause several types of cancer, including cancer of the cervix—the lower part of the womb.

A new Swedish study published in The BMJ adds evidence that HPV vaccination may also help protect future pregnancies. Researchers studied records from nearly 625,000 first births between 2006 and 2023. More than 92,000 of the mothers had received an HPV vaccine before pregnancy. The vaccine studied protects against four types of HPV.

After accounting for factors such as age and smoking, researchers found that vaccinated women had 5% lower odds of giving birth before 37 weeks, which is considered an early, or preterm, birth. They also had 15% lower odds of giving birth very early, between 28 and 31 weeks, and 8% lower odds of having a baby much smaller than expected for the length of the pregnancy.

These benefits were generally greater among women vaccinated at younger ages.

This matters because babies born too early or very small can face serious health problems. Even a small drop in these problems could help many families. One possible reason is that vaccination prevents HPV infections and reduces the need for treatments that remove damaged tissue from the cervix. Those treatments can raise the risk of early birth.

The vaccine’s protection against cervical cancer is already well supported. An earlier Swedish study of nearly 1.7 million girls and women found an 88% lower risk of cervical cancer among those vaccinated before age 17, compared with those who were not vaccinated. The new study suggests that protection may extend to healthier pregnancies later in life.