HARTFORD, CT — As promised, the state Department of Public Health has revised the data it released for last year’s school-based immunization rates.

The revised data, based on feedback from school districts, shows that 109 schools had kindergartens or seventh grades with immunization rates below the 95% standard for measles, mumps, and rubella for the 2017-18 school year. Last week, the original data release showed 116 schools with rates below the standard set by the Centers for Disease Control and Prevention.

Revised percentages for the number of religious or medical exemptions were updated for 11 schools after districts alerted the DPH about errors in the initial report. The revised data indicates that within the 109 schools with MMR vaccine rates below 95%, there were five schools in which less than 80% of kindergarteners were vaccinated for measles. Among seventh graders, five schools had MMR vaccine rates below 90%.

To derive the immunization data, schools report to the DPH the total number of students in kindergarten and seventh grade in each school, and then they report the total number of students who had either shown proof of vaccination or claimed an exemption. In Connecticut, exemptions to vaccination can either be for medical reasons as approved by a physician, or for religious reasons as stated by a child’s parent or guardian.

“I am glad we had this opportunity to update the school-based immunization data we released last week with slight corrections from a small number of schools,” said DPH Commissioner Renée Coleman-Mitchell. “I appreciate the cooperation we have received from school officials across the state as we all take a closer look at detailed, localized school immunization data for the first time in Connecticut. I think we can clearly say at this point that although our overall percentage of young children immunized for dangerous diseases such as measles is strong, there are some pockets of vulnerability.”

Measles outbreaks, like the nine that are ongoing in New York, California, Michigan, Maryland, Georgia, and New Jersey, are less likely to occur at schools in which a large majority of students are immunized to achieve herd immunity.

Herd immunity is described as a vaccination rate high enough to protect unvaccinated children. The Centers for Disease Control and Prevention says that number is 95%.

Measles, in particular, is highly infectious. According to the CDC:

Measles is a highly contagious virus that lives in the nose and throat mucus of an infected person. It can spread to others through coughing and sneezing. Also, measles virus can live for up to two hours in an airspace where the infected person coughed or sneezed. If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses, or mouths, they can become infected. Measles is so contagious that if one person has it, up to 90% of the people close to that person who are not immune will also become infected.

Infected people can spread measles to others from four days before through four days after the rash appears.

Possible complications from measles include pneumonia and encephalitis (swelling of the brain) — two conditions that can lead to hospitalization and death.

A group of mothers who are fighting to keep the religious exemption intact sent a letter from two doctors to Coleman-Mitchell Friday, which says that 100% vaccination “cannot reliably induce herd immunity.”

“Despite higher than average case of measles in 2019, Connecticut does not have a public health emergency warranting the repeal of the religious exemption,” Dr. Christopher Shaw and Dr. Alvin Moss wrote Friday in a letter to Coleman-Mitchell. “The data published by DPH is littered with inaccuracies and does not provide strong evidence to justify removing the religious exemption for a small minority of schoolchildren.”

Meanwhile, the newly revealed data prompted lawmakers to schedule a six-hour informational forum on vaccines Monday at 9:30 a.m. in Room 2E of the Legislative Office Building.

There’s no scheduled list of speakers for the forum, but it will be followed by an opportunity for the public to comment.

Lawmakers, who are sometimes criticized for rushing bills through the legislative process, are expected to use Monday’s public comment period as enough of an opportunity to raise an amendment on the floor for a vote on eliminating the religious exemption.

Senate President Martin Looney, D-New Haven, said Friday there’s cause for concern in a number of communities. He said some may be using the religious exemption to opt out of getting a vaccine, but there’s no organized religion that requires it.

He said he was just contacted by a large group of parents of kids who can’t be vaccinated and they are very concerned.

The DPH data is available here as MS Excel speadsheets:

Kindergarten 2017-18
Seventh grade 2017-18