People displaced by the earthquake hold medication in a school-turned-shelter in Adana, Turkey, February 7, 2023. REUTERS/Emilie Madi 

Saima, 23, displaced because of the floods, receives medical assistance while taking refuge in a school, following rains and floods during the monsoon season, in Karachi, Pakistan September 22, 2022. REUTERS/Akhtar Soomro 

Children, displaced because of the floods, receive medical assistance as their families take refuge in a school, following rains and floods during the monsoon season, in Karachi, Pakistan September 22, 2022. REUTERS/Akhtar Soomro 

Medical Examiner Dr. Terrill Tops enters the courtroom to testify during the penalty phase of the trial of Marjory Stoneman Douglas High School shooter Nikolas Cruz at the Broward County Courthouse, in Fort Lauderdale, U.S, August 1, 2022. Amy Beth Bennett/Pool via REUTERS 

Assistant State Attorney Mike Satz hands evidence photos to Medical Examiner Dr. Terrill Tops during the penalty phase of the trial of Marjory Stoneman Douglas High School shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, Florida, U.S, August 1, 2022. Amy Beth Bennett/Pool via REUTERS 

Assistant State Attorney Mike Satz questions Medical Examiner Dr. Terrill Tops as he testifies during the penalty phase of the trial of Marjory Stoneman Douglas High School shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, Florida, U.S, August 1, 2022. Amy Beth Bennett/Pool via REUTERS 

Retired Broward County Medical Examiner Craig Mallak goes over autopsy photos of shooting victim Cara Loughran during a the penalty phase of trial of Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, Florida, U.S., July 27, 2022. Mike Stocker/Pool via REUTERS 

Retired Broward County Medical Examiner Craig Mallak goes over autopsy photos of shooting victim Cara Loughran during a the penalty phase of trial of Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, Florida, U.S., July 27, 2022. Mike Stocker/Pool via REUTERS 

Max Schachter, the father of victim Alex Schachter, reacts as Dr. Rebecca MacDougall, the Chief Medical Examiner for Broward County Florida describes the gunshot his son sustained in the mass shooting, during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, U.S., July 26, 2022. Mike Stocker/Pool via REUTERS 

Jennifer and Tony Montalto listen to Dr. Marlin Osbourne, Assistant Medical Examiner for Palm Beach county testify about the gunshot wounds their daughter Gina Montalto sustained in the mass shooting, during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, U.S., July 26, 2022. Mike Stocker/Pool via REUTERS 

Dr. Marlin Osbourne, Assistant Medical Examiner for Palm Beach county testifies about the gunshot wounds victim Gina Montalto sustained in the mass shooting during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, U.S., July 26, 2022. Mike Stocker/Pool via REUTERS 

Dr. Rebecca MacDougall, the Chief Medical Examiner for Broward County Florida describes the gunshot wounds to victim Alex Schachter during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale, U.S., July 26, 2022. Mike Stocker/Pool via REUTERS 

Dr. Rebecca MacDougall, the Chief Medical Examiner for Broward County Florida describes the gunshot wounds to victim Alex Schachter. Marjory Stoneman Douglas High School shooter Nikolas Cruz is being tried in the penalty phase of his trial at the Broward County Courthouse, in Fort Lauderdale, U.S., July 26, 2022. Mike Stocker/Pool via REUTERS 

Medical Examiner Dr. Stephen Robinson looks at crime scene photos of the Marjory Stoneman Douglas High School victims during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale on Monday, July 25, 2022. Carline Jean/Pool via REUTERS 

Medical Examiner Dr. Wendolyn Sneed describes the wounds on a Marjory Stoneman Douglas High School victim during the penalty phase of shooter Nikolas Cruz at the Broward County Courthouse in Fort Lauderdale on Monday, July 25, 2022. Carline Jean/Pool via REUTERS 

George Daley, Dean of the Medical School, attends Harvard University's 371st Commencement Exercises in Cambridge, Massachusetts, U.S., May 26, 2022. REUTERS/Brian Snyder 

George Daley, Dean of the Medical School, speaks during Harvard University's 371st Commencement Exercises in Cambridge, Massachusetts, U.S., May 26, 2022. REUTERS/Brian Snyder 

Emergency medical workers cover pupils leaving from a school where shots were fired, in the northern city of Bremerhaven, Germany, May 19, 2022. REUTERS/Fabian Bimmer 

Emergency medical workers stand near a German school building where shots were fired, in the northern city of Bremerhaven, Germany, May 19, 2022. REUTERS/Fabian Bimmer 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

A general view of the Harvard Medical School in the Longwood Medical Area in Boston, Massachusetts, U.S., May 15, 2022. Picture taken with a drone. Picture taken May 15, 2022. To match Special Report HEALTH-HEARTS/STEM-CELLS REUTERS/Brian Snyder 

People take things out of a room where the medical centre of Velas is going to be fixed at Velas local school as small earthquakes have been recorded in Sao Jorge Island, Azores, Portugal, March 29, 2022. REUTERS/Pedro Nunes 

A woman evacuated from the Ukrainian city of Mariupol talks with a medic at a temporary accommodation centre for evacuees located in the building of a local sports school in Taganrog in the Rostov region, Russia March 23, 2022. REUTERS/Sergey Pivovarov 

Medical equipment waits for patients at a field hospital deployed by the humanitarian mission of the state of Israel on the premises of a local school, as Russia's invasion of Ukraine continues, in Mostyska, Ukraine March 20, 2022. REUTERS/Pavlo Palamarchuk 

Classroom converted to medical room waits for patients at a field hospital deployed by the humanitarian mission of the state of Israel on the premises of a local school, as Russia's invasion of Ukraine continues, in Mostyska, Ukraine March 20, 2022. REUTERS/Pavlo Palamarchuk 

Medical equipment waits for patients at a field hospital deployed by the humanitarian mission of the state of Israel on the premises of a local school, as Russia's invasion of Ukraine continues, in Mostyska, Ukraine March 20, 2022. REUTERS/Pavlo Palamarchuk 

Classroom converted to medical room waits for patients at a field hospital deployed by the humanitarian mission of the state of Israel on the premises of a local school, as Russia's invasion of Ukraine continues, in Mostyska, Ukraine March 20, 2022. REUTERS/Pavlo Palamarchuk 

Medical supplies wait to be unpacked at a field hospital deployed by the humanitarian mission of the state of Israel on the premises of a local school, as Russia's invasion of Ukraine continues, in Mostyska, Ukraine March 20, 2022. REUTERS/Pavlo Palamarchuk 

Medical equipment sits in the snow as police and paramedics respond to a shooting outside of the South Education Center school in Richfield, Minnesota, U.S., February 1, 2022. REUTERS/Christian Monterrosa 

Medical equipment sits next to bloodstains in the snow as police and paramedics respond to a shooting outside of the South Education Center school in Richfield, Minnesota, U.S., February 1, 2022. REUTERS/Christian Monterrosa 

Medical personnel prepare to administer coronavirus disease (COVID-19) vaccinations to pupils at a primary school in Naples, Italy, January 12, 2022. REUTERS/Ciro De Luca 

A stone with the words "Remote School" forms part of the "COVID-19 Cairn," which "stands to honor our community's journey through the landscape of COVID-19," at Tufts Medical Center in Boston, Massachusetts, U.S., January 5, 2022. REUTERS/Brian Snyder 

A medical worker holds a syringe with a dose of the Moderna vaccine against the coronavirus disease (COVID-19), on the day the government is expected to approve new rules for schools and COVID-19 vaccination for workers, at the Music Auditorium in Rome, Italy, January 5, 2022. REUTERS/Guglielmo Mangiapane 

People sit next to a coronavirus disease (COVID-19) test sign outside the School of Nursing in Jinnah Postgraduate Medical Centre (JPMC), in Karachi, Pakistan December 9, 2021. REUTERS/Akhtar Soomro 

A man reacts as a paramedic takes a swab sample, to be tested for the coronavirus disease (COVID-19), from a window at the School of Nursing in Jinnah Postgraduate Medical Centre (JPMC) in Karachi, Pakistan December 9, 2021. REUTERS/Akhtar Soomro TPX IMAGES OF THE DAY 

Parents hold their child as a paramedic takes a swab sample from a window, to be tested for the coronavirus disease (COVID-19), at the School of Nursing in Jinnah Postgraduate Medical Centre (JPMC) Karachi, Pakistan December 1, 2021. REUTERS/Akhtar Soomro 

A woman reacts as a paramedic takes a swab sample from a window, to be tested for the coronavirus disease (COVID-19), at the School of Nursing in Jinnah Postgraduate Medical Centre (JPMC) Karachi, Pakistan December 1, 2021. REUTERS/Akhtar Soomro 

Dr. Sarah Linde with the Maryland Medical Reserve Corps gives Luca Starling, 10, his first COVID-19 vaccination at Eastern Middle School in Silver Spring, Maryland, U.S., November 6, 2021. Picture taken November 6, 2021. REUTERS/Evelyn Hockstein 

Dr. Sarah Linde with the Maryland Medical Reserve Corps gives Noah Starling, 7, his first COVID-19 vaccination, at Eastern Middle School ahead of the Thanksgiving holiday, in Silver Spring, Maryland, U.S., November 6, 2021. Picture taken November 6, 2021. REUTERS/Evelyn Hockstein 

Dr. Sarah Linde with the Maryland Medical Reserve Corps gives Noah Starling, 7, his first COVID-19 vaccination while Noah's mom Tanya Primiani takes a photo, at Eastern Middle School in Silver Spring, Maryland, U.S., November 6, 2021. Picture taken November 6, 2021. REUTERS/Evelyn Hockstein 

Dr. Sarah Linde with the Maryland Medical Reserve Corps offers Noah Starling, 7, lollipops following his first COVID-19 vaccination, at Eastern Middle School in Silver Spring, Maryland, U.S., November 6, 2021. Picture taken November 6, 2021. REUTERS/Evelyn Hockstein 

Dr. Sarah Linde with the Maryland Medical Reserve Corps gives Noah Starling, 7, his first COVID-19 vaccination, at Eastern Middle School ahead of the Thanksgiving holiday, in Silver Spring, Maryland, U.S., November 6, 2021. Picture taken November 6, 2021. REUTERS/Evelyn Hockstein 

Kids await for medical discharge after receiving a dose of the Sinovac vaccine against the coronavirus disease (COVID-19) at a public school in Concon, Chile September 27, 2021. REUTERS/Rodrigo Garrido 

Kids await for medical discharge after receiving a dose of the Sinovac vaccine against the coronavirus disease (COVID-19) at a public school in Concon, Chile September 27, 2021. REUTERS/Rodrigo Garrido 

A girl awaits for medical discharge after receiving a dose of the Sinovac vaccine against the coronavirus disease (COVID-19) at a public school in Concon, Chile September 27, 2021. REUTERS/Rodrigo Garrido 

Girls wait for medical discharge after receiving a dose of the Sinovac vaccine against the coronavirus disease (COVID-19) at a public school in Concon, Chile September 27, 2021. REUTERS/Rodrigo Garrido 

Kids await for medical discharge after receiving a dose of the Sinovac vaccine against the coronavirus disease (COVID-19) at a public school in Concon, Chile September 27, 2021. REUTERS/Rodrigo Garrido 

A medical worker observes secondary school students after they receive a dose of the coronavirus disease (COVID-19) vaccine at a school, in Putrajaya, Malaysia, September 20, 2021. REUTERS/Lim Huey Teng 

Every U.S. state requires vaccines for public school students. See which vaccines are mandated and which exemptions are allowed by your state. Vaccine mandates are not absolute. States offer exemptions for medical, religious or philosophical reasons. 

Every U.S. state requires vaccines for public school students. See which vaccines are mandated and which exemptions are allowed by your state. Vaccine mandates are not absolute. States offer exemptions for medical, religious or philosophical reasons. 

A medical worker in a school hall administers a dose of the Pfizer-BioNTech COVID-19 vaccine to a student of the Leibniz-Montessori secondary school, amid the coronavirus disease (COVID-19) pandemic, in Dusseldorf, Germany, August 27, 2021. REUTERS/Thilo Schmuelgen 

A medical worker in a school hall administers a dose of the Pfizer-BioNTech COVID-19 vaccine to a student of the Leibniz-Montessori secondary school, amid the coronavirus disease (COVID-19) pandemic, in Dusseldorf, Germany, August 27, 2021. REUTERS/Thilo Schmuelgen 

A medical worker in a school hall administers a dose of the Pfizer-BioNTech COVID-19 vaccine to a student of the Leibniz-Montessori secondary school, amid the coronavirus disease (COVID-19) pandemic, in Dusseldorf, Germany, August 27, 2021. REUTERS/Thilo Schmuelgen 

An injured patient is loaded by volunteer medics to a school bus to be transported to a hospital, after Saturday's 7.2 magnitude earthquake in Les Cayes, Haiti August 19, 2021. REUTERS/Ricardo Arduengo 

Nippon Medical School Hospital's ICU doctor Shoji Yokobori rides in a subway train as he heads to Tokyo International Forum, the weightlifting venue of Tokyo 2020 Olympic Games, where he works as an emergency medicine officer overseeing the venue in Tokyo, Japan, August 2, 2021. Picture taken on August 2, 2021. REUTERS/Kim Kyung-Hoon