TEXAS (NEXSTAR) — Vaccination rates for kindergarteners in Texas and across the nation dropped again last year, and federal officials are starting a new campaign to try to bring them up.

Usually, 94% to 95% of kindergarteners are vaccinated against measles, tetanus and certain other diseases. Nationwide, the vaccination rates dropped below 94% in the 2020-2021 school year, during the first year of the COVID-19 pandemic.

A Centers for Disease Control and Prevention study released Thursday found rates dropped again in the 2021-2022 school year, to about 93%.

In Texas, immunization coverage was above 95% for only one vaccine – Hepatitis B. According to a report released by the Texas Health and Human Services, delinquency rates in kindergarten students have increased for another year since the pandemic, with four vaccines now having delinquency rates over three percent.

Examining state data from entering public school kindergarten students, 97.01% of children received their MMR vaccine in 2017-2018. The number dropped in the 2021-2022 school year to 94.04%.

According to the report from the Centers for Disease Control and Prevention, the Houston area is lower than the state averages.  Only 88.2% of children have received 2 doses of the MMR vaccine.

The pandemic disrupted vaccinations and other routine health care for children, and also taxed the ability of school administrators and nurses to track which children weren’t up-to-date on shots. CDC officials said decreased confidence in vaccines is another likely contributor.

“I think it’s a combination of all those things,” said Dr. Georgina Peacock, director of CDC’s immunization division.

Health officials focus on kindergarten because it’s when most children enter school systems. Public schools typically require vaccinations as a condition of attendance, though some exemptions are allowed.

Such exemptions were up slightly last school year, but the CDC’s Shannon Stokley said they are not the main driver of the decrease. Rather, more schools relaxed their policies to allow enrollment while giving families a grace period to get shots, she said.

The Associated Press contributed to this report.