Measles cases are accelerating in the United States, with twice as many confirmed cases as last year, and more parents are opting for earlier vaccination – including the second dose of the measles, mumps, and rubella (MMR) vaccine, which can be administered as early as four weeks after the first.
Giving the second shot shortly after the first is what some other countries, such as Germany, the United Kingdom and France, recommend — and the U.S. Centers for Disease Control and Prevention (CDC) also says it’s an option.
“More and more parents are hearing about doing it ‘early,'” said Elias Kass, a naturopathic doctor and vaccine advocate in Seattle, Washington. The CDC generally recommends giving the first MMR injection after age one and the second between four and six years of age. But Kass began recommending the MMRV vaccine, which combines the second MMR and varicella (chickenpox), at age 15 months, when measles cases began to increase a few years ago.
More parents are now following this recommendation, he said, adding that their reasoning is quite simple: “There’s no reason to wait, measles is here now.” »
Margot Taylor, a mother in Chicago, has three young children with three different vaccination histories for the MMR vaccine.
“All three are fully vaccinated, but that had to be expedited due to the increase in cases,” Taylor said. “We’ve gone so far backwards.”
His eldest, born in 2019, received his vaccines at the ages of one and four. Measles “wasn’t on my radar,” Taylor said. “I didn’t even think about it.”
But with her second child, born in 2023, Taylor was surprised when the pediatrician recommended the second shot at age two. Chicago was dealing with a measles outbreak, so they kept going.
Her third child, born in 2025, received the first injection after his first birthday – then the second three months later, in June.
Taylor worried the shots wouldn’t work as well if they were so early. But evidence shows that vaccines still work well at early ages; The recommendation to administer the MMR dose between ages four and six is based more on logistical concerns, to ensure children receive both shots before entering kindergarten and to reduce doctor visits, as other shots are also typically given at these ages.
And Taylor knows how vital MMR vaccines are. When her third daughter was too young to receive the first dose, she was exposed to measles at an airport during the outbreak in West Texas. When the baby, just a month old, developed a fever, they rushed to the hospital and stayed in a negative pressure room until testing negative for measles.
“I’m relieved and I still can’t say enough how grateful I am” for the vaccines, Taylor said. But she still questions the need to make these decisions. “I never thought I would have to learn vaccination schedules,” she said.
Germany had similar recommendations to the United States until 2001, when an outbreak caused a wave of illness and death that led the country to recommend the first shot between 11 and 14 months and the second between 18 and 23 months. In 2020, they moved the second dose four weeks after the first.
“So far, there is no evidence that a child vaccinated twice, regardless of the rate, has a higher risk of measles than a child vaccinated according to the old rule,” said Catherina Becker, a German scientist.
Her son was two and a half years old when he received his second measles vaccine – and it was delayed only because he was recovering from a case of chickenpox. The CDC should “absolutely” consider a stronger recommendation to give the second dose sooner, Becker said.
Some parents also choose to have their baby vaccinated for the first time at six months of age — which the CDC recommends in areas with outbreaks, before international travel, and after exposure to measles. These infants should also receive a third dose.
If a mother was vaccinated against measles before pregnancy, this immunity is shared in utero, so the baby is protected for the first few months of life. This is why a third dose is recommended if infants receive the first dose earlier – as it is possible that the baby may still have maternal antibodies and therefore not establish a strong response to the vaccine at six months.
The second MMR vaccine is different from other boosters. Most people react strongly to the first injection, which is why only one injection was recommended until 1989. But scientists have found that some people don’t react to the first injection and need a second one – which is why the booster shot was recommended. This is also why people born before 1989 might need a second shot now.
“It’s a second chance to answer for the first time,” Kass said.
Becker looks at past outbreaks to understand the effectiveness of the shots. During an outbreak in Alaska in 1998, only 17 people became ill at a school where almost every student — some 2,186 in total — had received a measles vaccine. She compared it to a 2010 outbreak at a Waldorf school in Germany, where nearly half of the 300 students were unvaccinated and 71 people were sick.
“It shows you what the measles vaccine does for you – it protects you against this disease,” she said.
Gn Health
