Routine childhood vaccinations dropped dramatically during the early months of the coronavirus pandemic, and although they began rebounding last summer as families rescheduled doctors’ visits, many children and adolescents are behind on their shots, according to a federal health report released Thursday.

Researchers found that shots for children and teens between March and May 2020 were substantially lower for routine vaccinations, including for DTaP (diphtheria, tetanus and acellular pertussis), measles, and HPV, across all age groups, compared to the same three-month period in 2018 and 2019.

Among children younger than 24 months old and children 2 to 6 years old, doses of DTaP fell a median of almost 16 percent and 60 percent, respectively, across all jurisdictions compared with the same period in 2018 and 2019.

Doses of measles, mumps and rubella vaccine, MMR, given to children 12 to 23 months and 2 to 8 years old, fell a median of 22 percent and 63 percent.

Among children 9 to 12 years old and teens ages 13 to 17, doses of human papilloma virus vaccine (HPV) fell almost 64 percent and 71 percent, compared with doses administered in the two previous years.

But the rebound “was not sufficient to achieve the catch-up vaccination needed to address the many months when children missed routine vaccination,” it said.

And 40 percent of parents surveyed by Blue Cross said their children missed shots because of the pandemic.