Melissa Blatzer was determined to get her three children caught up on their routine immunizations on a recent Saturday morning at a walk-in clinic in this Denver suburb. It had been about a year since the kids' last shots, a delay Blatzer chalked up to the pandemic.
Two-year-old Lincoln Blatzer, in his fleece dinosaur pajamas, waited anxiously in line for his hepatitis A vaccine. His siblings, 14-year-old Nyla Kusumah and 11-year-old Nevan Kusumah, were there for their TDAP, HPV and meningococcal vaccines, plus a COVID-19 shot for Nyla.
"You don't have to make an appointment and you can take all three at once," said Blatzer, who lives several miles away in Commerce City. That convenience outweighed the difficulty of getting everyone up early on a weekend.
Child health experts hope community clinics like this, along with the return to in-person classes, more well-child visits and the rollout of COVID shots for younger children, can help boost routine childhood immunizations, which dropped during the pandemic. Despite a rebound, immunization rates are still lower than in 2019, and disparities in rates between racial and economic groups, particularly for Black children, have been exacerbated.
"We're still not back to where we need to be," said Dr. Sean O'Leary, a pediatric infectious-disease doctor at Children's Hospital Colorado and a professor of pediatrics at the University of Colorado School of Medicine.
Routine immunizations protect children against 16 infectious diseases, including measles, diphtheria and chickenpox, and inhibit transmission to the community.
The rollout of COVID shots for younger kids is an opportunity to catch up on routine vaccinations, said O'Leary, adding that children can receive these vaccines together. Primary care practices, where many children are likely to receive the COVID shots, usually have other childhood vaccines on hand.
"It's really important that parents and health care providers work together so that all children are up to date on these recommended vaccines," said Dr. Malini DeSilva, an internist and pediatrician at HealthPartners in the Minneapolis-St. Paul area. "Not only for the child's health but for our community's health."
People were reluctant to come out for routine immunizations at the height of the pandemic, said Karen Miller, an immunization nurse manager for the Denver area's Tri-County Health Department, which ran the Westminster clinic. National and global data confirm what Miller saw on the ground.
Global vaccine coverage in children fell from 2019 to 2020, according to a recent study by scientists at the Centers for Disease Control and Prevention, the World Health Organization and UNICEF. Reasons included reduced access, lack of transportation, worries about COVID exposure and supply chain interruptions, the study said.
Third doses of the diphtheria, tetanus and whooping cough (DTP) vaccine and of the polio vaccine decreased from 86% of all eligible children in 2019 to 83% in 2020, according to the study. Worldwide, 22.7 million children had not had their third dose of DTP in 2020, compared with 19 million in 2019. Three doses are far more effective than one or two at protecting children and communities.
In the United States, researchers who studied 2019 and 2020 data on routine vaccinations in California, Colorado, Minnesota, Oregon, Washington and Wisconsin found substantial disruptions in vaccination rates during the pandemic that continued into September 2020. For example, the percentage of 7-month-old babies who were up to date on vaccinations decreased from 81% in September 2019 to 74% a year later.
The proportion of Black children up to date on immunizations in almost all age groups was lower than that of children in other racial and ethnic groups. This was most pronounced in those turning 18 months old: Only 41% of Black children that age were caught up on vaccinations in September 2020, compared with 57% of all children at 18 months, said DeSilva, who led that study.
A CDC study of data from the National Immunization Surveys found that race and ethnicity, poverty and lack of insurance created the greatest disparities in vaccination rates, and the authors noted that extra efforts are needed to counter the pandemic's disruptions.
In addition to the problems caused by COVID, Miller said, competing life priorities like work and school impede families from keeping up with shots. Weekend vaccination clinics can help working parents get their children caught up on routine immunizations while they get a flu or COVID shot. Miller and O'Leary also said reminders via phone, text or email can boost immunizations.
"Vaccines are so effective that I think it's easy for families to put immunizations on the back burner because we don't often hear about these diseases," she said.
It's a long and nasty list that includes hepatitis A and B, measles, mumps, whooping cough, polio, rubella, rotavirus, pneumococcus, tetanus, diphtheria, human papillomavirus and meningococcal disease, among others. Even small drops in vaccination coverage can lead to outbreaks. And measles is the perfect example that worries experts, particularly as international travel opens up.
"Measles is among the most contagious diseases known to humankind, meaning that we have to keep very high vaccination coverage to keep it from spreading," said O'Leary.
In 2019, 22 measles outbreaks occurred in 17 states in mostly unvaccinated children and adults. O'Leary said outbreaks in New York City were contained because surrounding areas had high vaccination coverage. But an outbreak in an undervaccinated community still could spread beyond its borders, he said.
In some states a significant number of parents were opposed to routine childhood vaccines even before the pandemic for religious or personal reasons, posing another challenge for health professionals. For example, 87% of Colorado kindergartners were vaccinated against measles, mumps and rubella during the 2018-19 school year, one of the nation's lowest rates.
Those rates bumped up to 91% in 2019-20 but are still below the CDC's target of 95%.
O'Leary said he does not see the same level of hesitancy for routine immunizations as for COVID. "There has always been vaccine hesitancy and vaccine refusers. But we've maintained vaccination rates north of 90% for all routine childhood vaccines for a long time now," he said.
Malini said the "ripple effects" of missed vaccinations earlier in the pandemic continued into 2021. As children returned to in-person learning this fall, schools may have been the first place families heard about missed vaccinations. Individual states set vaccination requirements, and allowable exemptions, for entry at schools and child care facilities. Last year, Colorado passed a school entry immunization law that tightened allowable exemptions.
"Schools, where vaccination requirements are generally enforced, are stretched thin for a variety of reasons, including COVID," said O'Leary, adding that managing vaccine requirements may be more difficult for some, but not all, schools.
Anayeli Dominguez, 13, was at the Westminster clinic for a TDAP vaccine because her middle school had noticed she was not up to date.
"School nurses play an important role in helping identify students in need of immunizations, and also by connecting families to resources both within the district and in the larger community," said Denver Public Schools spokesperson Will Jones.