OSMS has compiled a Back to School Guide in an effort to highlight international best practices for schooling during the COVID-19 pandemic. We present this here in an effort to consolidate the significant amount of existing information into a comprehensible analysis for educators and administrators. This guide incorporates 81 resources from institutions, organizations, case studies, media outlets, and research evaluations from around the world into a single repository.
**The primary purpose of this guide is to highlight both effective and ineffective strategies to help educators and administrators plan how best to safely and responsibly return to the classroom.**
As COVID-19 swept the globe, governments and health ministries around the world temporarily closed educational institutions in an effort to reduce the spread of the virus within communities. Global monitoring of school closures conducted by UNESCO indicates over 1 billion students are still impacted by school closures, with 106 country-wide school closures currently in effect as of August.  Evaluations of data from previous epidemics have shown that closing schools is an important part of a public health strategy aimed at slowing the community spread of a virus.    While initially necessary to “flatten the curve,” many communities have begun, or are preparing for, the eventual return of students to their classrooms. Education in a structured school environment provides numerous benefits towards the general wellbeing of children.
Schools provide children with a consistent schedule of learning and social interactions while serving as a structure for education and an environment for cultivating peer relationships. These relationships foster the development of language, communication, social, emotional, and interpersonal skills.  Many students also depend on school meals to address nutritional needs and physical education or sports programs to provide physical activity.  This decision to return students to the classroom should be based on thorough risk assessment regarding the level of viral activity within the community, and should include an understanding of transmission, as well as the readiness of the schools to address the possibility of emergence or management of an outbreak. 
The role of children, especially younger children, in the transmission of COVID-19 to others is not entirely understood. Older children and adolescents (ages 10-19) are able to transmit the virus effectively.  Cases of probable transmission from teachers to students, and cases of viral transmission between students, in the school setting have also been identified.  Typical school settings that consist of crowded classrooms, cafeterias and hallways with poor air circulation that students, teachers and administrators occupy for multiple hours per day represent very high risk environments for COVID-19 transmission, given what we know about the virus’ transmissibility.
Guidelines for in-person learning will vary across regions or countries, and in accordance with local health departments, but many share key recommendations. Before schools can safely reopen, they should ensure the necessary resources, policies and infrastructure are in place that protect the health and safety of all students and staff. . This includes having a strategy for distance learning ready, and being fully prepared to transition students to distance learning in the event of a COVID outbreak. 
Public Health Strategies for In-Person Education
There are numerous precautions and practices that must be implemented if a school plans to provide in-person education. One of the most important considerations for returning students to in-person learning is how widespread the virus is in the community as a whole. Areas with significant viral activity will be riskier due to the potential for students to introduce the virus from the community into the school population.  
The following precautions represent various strategies that can be used in conjunction with each other to create safer school environments.
Social distancing refers to measures that restrict how closely people can gather in order to stop or slow the spread of an infectious disease. According to the CDC, 6 feet (2 meters) of separation is the minimum distance that should be kept between people while interacting.  Maintaining social distance is especially challenging in a school setting with teachers and students working together in classrooms, students socializing throughout the day, and school buildings serving as a gathering space.  When implemented correctly, social distancing reduces the transmissibility of COVID-19 from viral droplets.
The following methods can be used to achieve social distancing in school environments:
- Establish alternatives for scheduling students to reduce school density and exposure time, such as rotating in-person learning with virtual learning, shorter school weeks, shorter school days, or having students come in on alternating days. 
- Repurpose unused school or community spaces to increase the physical amount of space students can occupy to ensure distance. 
- Move classes outdoors when possible. 
- Re-arrange desks to increase space, divide classes into smaller groups, and require students to remain seated in the classroom. 
- Stagger break times and transition times during which students enter and exit the school to reduce crowding in high traffic areas (hallways, cafeterias, etc). 
- Implement restrictions around the use of lockers to prevent crowding in hallways.
- Cancel performances, sports practices, or games. 
- Do not allow parents or other visitors; restrict vendor access to school 
One particularly impactful strategy that administrators should consider is cohorting. Cohorts (sometimes called “learning pods”) are groups of students and their teachers that remain together throughout the school day to minimize overall exposure.  When implemented correctly, cohorts can minimize the impact of quarantines and restrict them to small groups of students instead of entire school systems.
The following methods can be used to implementing cohorting in school environments:
- Cohorts should be kept at a size which is small enough to allow for social distancing guidelines to be followed within the classroom.
- Schools should keep cohorts together in one classroom with the option to have teachers rotate between rooms to minimize the possibility for viral transmission.
- Schools may alternate cohorts by days or weeks, and adopt a hybrid approach, with some cohorts assigned to in-person learning and others assigned to virtual learning. 
- If a student within a cohort contracts COVID, the school should quarantine the entire cohort so as not to risk spreading the virus.
- Keep student cohorts separated from one another to reduce viral transmission through the school population. 
Widespread use of face masks and social distancing by students, teachers and staff are critical components of safe in-person education. Students of all ages should be encouraged to adopt these behaviors while in school, and within their communities. Masks are an important part of preventing the spread of respiratory droplets which can infect others with COVID-19.  Widespread face mask use has been found to be the single biggest determinant in positive public health outcomes throughout this pandemic. 
The following methods can be used to achieve widespread mask usage in school environments:
- Schools should include masks on school supply lists.
- Schools should have additional masks available for students, teachers, and staff.
- Normalize proper mask usage as a part of school dress code, and enforce it as such.
- Ensure that students and staff are aware of the correct use of masks, including wearing masks over the nose and mouth and securely around the face. 
- Expect that younger children (elementary school age) will struggle to adapt to wearing masks. Have teachers and staff communicate and reinforce appropriate mask usage in a way that is appropriate for students within their age group. 
- Include reminders about face coverings in announcements, school newspapers, and other materials.
- Post age-appropriate signs throughout the school reminding students of proper mask usage, including reminders that a clean mask must be worn daily.
- Parents and caregivers may disagree with school policies about masks. Schools should have a plan to address these challenges should they arise. 
Implementing proper hand hygiene practices is a simple yet effective way to reduce the spread of COVID-19 via contaminated surfaces. Hand hygiene refers to using soap and water to thoroughly clean the hands, or the use of an alcohol-based hand sanitizer if soap and water are unavailable.  Good hand hygiene will help prevent infections from students, teachers and administrators touching their faces after touching contaminated surfaces.
The following methods can be used to achieve better hand hygiene in school environments:
- Educate and reinforce handwashing with soap and water for at least 20 seconds and increase monitoring to ensure adherence among students, teachers, and staff. 
- Add time in the daily schedule for students and staff to wash hands, particularly before lunch, or after recess. Account for the additional time students or staff may need to wash their hands while maintaining social distancing. 
- Provide hand sanitizers with at least 60% alcohol for students, teachers, and staff near high-touch surfaces (e.g., water fountains, doors).
- If running water is unavailable, hands may be rinsed with a soapy water or detergent and water mixture poured from a bottle, followed by rinsing with plain water from a different bottle. 
- If soap and water or hand sanitizer are unavailable, rinsing hands with a 0.05% chlorine solution is a temporary option. The solution must be replaced daily and can be made by following the instructions found here.
- Promote good hand hygiene by placing posters or stickers in visible locations and also include reminders in daily announcements. The CDC provides posters available for download.
- Students and staff should be monitored for skin reactions from frequent hand hygiene and protocols may need to be adjusted accordingly.
Cleaning and Disinfecting
Stringent environmental cleaning and disinfecting measures should be in place to limit the risk of exposure or transmission via surfaces. Cleaning physically removes dirt and germs from surfaces using soap and detergent. Disinfecting requires use of a chemical to kill germs on the surfaces of objects. 
The following methods can be used to better decontaminate surfaces in school settings:
- Schools should modify their standard procedures to accommodate more frequent cleaning and disinfection.
- Staff should be trained in thorough disinfection of high-touch surfaces and shared objects in addition to standard cleaning procedures. 
- Cleaning and disinfection instructions should be provided in other languages if required by staff.
- Anyone using cleaners and disinfectants should read and understand all instruction and warning labels to ensure safe and appropriate use of the products.
- Ensure proper ventilation during use of cleaning and disinfecting products to prevent exposing children to potentially harmful fumes or vapors.
- When possible, limit the use of shared objects such as: gym equipment, musical instruments, art supplies, toys, games, and electronic devices, or clean and disinfect shared objects between use. 
- Discourage sharing of items that are difficult to clean or disinfect such as: pens and pencils, whiteboard markers and erasers, books, and other learning aids.
- Consider removing soft, porous materials like area rugs and cushions to reduce difficulties with cleaning and disinfecting them. 
- Keep each student’s belongings separate in individual containers or cubbies to reduce the need to clean and disinfect shared items.
- Consult this US EPA list for sprays, wipes, and concentrated solutions approved for killing the virus that causes COVID-19.
As evidence increases that COVID-19 can linger in the air as an aerosol, and several previous outbreaks have been linked to environments with poor ventilation or recirculated air, it is strongly advised that adequate ventilation be used inside buildings without recirculating internal air.  Aside from widespread face mask usage and social distancing, proper ventilation (or at least limited recirculation) is one of the most important factors to prevent transmission.
The following methods can be used to address ventilation in school environments:
- The safest solution would be to hold classes outdoors, where no air is being re-circulated and contaminated air does not linger near healthy people.
- If outdoor classes are not feasible, mechanical ventilation systems can sometimes draw air from outside and distribute it throughout the building, instead of recirculating internal air. 
- In the absence of mechanical ventilation systems, schools should consider opening classroom windows, preferably in a configuration which would increase natural air flow.
- Box fans or window fans may be used in a way to bring in fresh outdoor air and pull out indoor air, if care is taken to not blow air directly across students or teachers (so as to not blow potentially contaminated air onto others).
- Consideration should be given to installing air filters capable of filtering viral particles into mechanical ventilation systems. Filters should be inspected and exchanged regularly to ensure adequate air flow and filtration. 
- Portable HEPA filters and air purifiers can be added to classrooms to augment air filtration in absence of mechanical ventilation.
- If ventilation is absolutely not possible, filters and duct systems should be cleaned regularly and heating and cooling systems should be well maintained. 
Successful Implementation of Public Health Measures
Developing and implementing strong practices aimed at reducing the transmission of COVID-19 must be a top priority for schools. It is critically important to recognize the degree of infection within the communities surrounding a school. Communities with high infectivity rates will be more at risk, even with good public health strategies in place.  The following case studies illustrate what successfully returning students to the classroom entails.
When COVID-19 began to spread across the globe, Denmark ordered a month-long lockdown. When Danish schools did reopen, there were only 185 new cases (31.8 new cases per million people) daily in the country, indicating relatively low viral activity throughout the nation. Initially, only younger students in grades 1-5 were returned to their classrooms. By the end of May, all grades K-12 were permitted to return. 
Schools throughout Denmark followed strong guidance on how to modify the learning environment to prevent the spread of COVID-19. Class sizes were limited to cohorts of 10-12 students,with only one teacher teaching any given cohort throughout the day. Parents and visitors were not allowed into schools except under special circumstances. Entry and dismissal times were staggered and cohorts were not allowed to mingle. 
To facilitate social distancing, public parks were reserved between 8 a.m. and 3:30 p.m. for outdoor learning spaces, while hotels, libraries, and conference centers were also made available for schools. Initially, students were seated in arrangements allowing for a minimum of 6 feet (2 meters) of space between students; however, by May this was reduced to 3 feet (1 meter). 
The use of face masks was not required for children or teachers, but masks were recommended for students who were taking public transportation. Students had to wash their hands upon arriving at school, after breaks, before going home, after using the bathroom, as well as before and after eating. This rule was eventually relaxed because some children developed skin conditions and irritation. 
The Denmark Ministry of Education established a hotline to help schools assess learning, access and make use of public spaces, and consult on other education-specific issues. The nation’s Board of Health published a guide for school administrators, teachers and students. 
As of September 8, Denmark has maintained a steady low number of new cases per day, with 174 new cases per day (30.0 new cases per million people). 
The Taiwanese government took rapid, early actions when it first became aware of a respiratory virus spreading in Wuhan, China. Temperature checks were conducted outside of public buildings and hand sanitizer stations were distributed immediately. People adopted mask wearing in public.In February, Taiwan increased its mask and alcoholic sanitizer production, and set cleaning standards for public transportation and schools. The export of masks was not permitted and masks were rationed and distributed to citizens. 
Taiwan had very low viral activity within communities. In March, there were only 153 confirmed cases and two deaths in Taiwan, out of a population of 23 million. Schools were never ordered to close, and students returned to the classroom following their winter break with extra precautions and practices in place. 
Before students left their homes in the morning, parents took the student’s temperature and reported it to their school. Students of all ages wore masks throughout the day, except at lunch. During their lunch break, students set up transparent partitions in the cafeteria before removing their masks to eat. Additionally, teachers instructed students to wash their hands regularly throughout the day and provided instruction on proper hand hygiene. 
The fast and early response of the government contributed to the success of Taiwan in preventing a large COVID-19 outbreak. The government used experience from the 2003 SARS outbreak to establish a public health response which enabled their rapid action against the spread of COVID-19.  This early action meant that viral activity within the community remained low, and activities such as work, shopping, and school were able to continue with minor preventive measures in place. 
As reported on September 8, Taiwan has continued to maintain a low infection rate with only 495 cases and 7 deaths reported since the beginning of the COVID-19 pandemic. 
In early March, health officials began urging the public to wear masks and practice social distancing as COVID-19 began to spread globally. Uruguay closed all schools on March 13 for 5 weeks. Many local businesses stayed open; however, the country closed its borders. At the end of April students in rural areas began attending classes in person 3 days a week at a maximum 4 hours per day. Virus transmission remained low throughout the country, and by the end of June students at all public schools were allowed to return to their classrooms.  
Uruguay’s successful re-opening of schools can be largely attributed to the rapid response of the government and citizens’ adherence to the early guidance put forth by the country’s health officials. Additional measures including voluntary quarantine, widespread monitoring and tracking of disease activity, and randomized tests were implemented proactively throughout Uruguay. Citizens viewed the government’s actions favorably and understood that following social distancing guidelines and adhering to a mask policy were important for curbing the spread of COVID-19. 
As of September 8, Uruguay has reported a total of 1,693 COVID-19 infections and only 45 deaths since the beginning of the pandemic. 
Unsuccessful Implementation of Public Health Measures
As important as it is to understand the strategies and practices in use by schools that have not had significant spread, it is equally important to understand which circumstances are ineffective and should be avoided. While there are likely many more instances of COVID-19 spreading within schools, many of these are being underreported, or not reported at all . The following examples were made visible through media outlets and social media.
North Paulding High School, Georgia (USA)
Students returned to school August 3rd. Within the first 2 days, photos (available here and here) had been posted on social media by students showing crowded hallways, very few masks, and no social distancing on school buses and in the hallways between classes. Masks are “strongly encouraged,” but not required. More than 2,000 students attend the high school.
The school closed temporarily for virtual learning after numerous cases were confirmed. As of early September, 62 cases have been reported . Students will now be on campus for two days a week based on their last names and will spend the rest of their school week engaging in digital learning as per a new hybrid learning system. .
As of September 8, the state of Georgia has reported 285,350 COVID-19 cases and 6,070 deaths since the beginning of the pandemic. 
Gymnasia Rehavia (Gymnasia Ha’ivrit), West Jerusalem (Israel)
In early May Israel had one of the lowest rates of COVID-19 in the world. New cases had dropped to a few dozen per day, and fewer than 250 people had died from the virus.  High school students returned to their classrooms for in-person learning in staggered smaller groups (cohorts). On May 17th restrictions on class sizes were removed. Classrooms were crowded with 35-38 students per class and social distancing was not possible. Most students use public transportation or school buses with the approximate amount of time spent on the bus is 20-45 minutes of travel. Most students also participate in extracurricular activities such as sports or dance for an average of 2-4 hrs per week. 
The region experienced extreme heat from the 19th to 21st of May, during which schoolchildren were not required to wear facemasks for 3 days and the air-conditioning system functioned continuously.  Within one week, 153 students and 25 staff members contracted COVID-19. Officials ordered dozens of schools to close following the outbreak, and a new policy was put into place requiring any schools with active cases of COVID-19 to close. 
As of September 8, Israel has reported 137,565 cases and 1,040 deaths during the COVID-19 pandemic. 
University of Alabama, Tuscaloosa (USA)
In June, the governor of Alabama announced a statewide student testing program to help public universities and colleges reopen for in-person classes. The program focused on testing more than 160,000 students for the virus before they arrive at 59 local colleges and universities. The program also required students to wear masks and follow social-distancing guidelines. Many university administrators acknowledged the potential for new outbreaks with the state of Alabama having one of the nation’s highest per capita infection rates.  
On August 19th in-person classes resumed at the University of Alabama Tuscaloosa campus. By August 28th, 9 days later, a total of 1,043 students had tested positive for coronavirus on campus. Many students disregarded guidelines set by the university to keep the school safe and the uptick in cases was attributed to students attending parties and visiting bars. The mayor of Tuscaloosa promptly ordered the city’s bars to close for 2 weeks and university police and Tuscaloosa police were ordered to monitor restaurants, off-campus residences and Greek (fraternity and sorority) housing to ensure patrons and residents follow safety guidelines. The university consolidated student housing to clear room to quarantine students, banned student events and encouraged compliance with preventative measures. Students can now choose to take all their classes online at any time.  
As of September 8, Alabama has reported 133,606 cases and 2,277 deaths since the beginning of the pandemic. 
Given that cases of transmission have occurred in school settings, it is important to acknowledge the likelihood of serious illnesses or deaths occurring within school communities, including illnesses or deaths among teachers, administrators, and students’ family members. These events can be traumatizing and may impact teachers, staff, students, and their families. Schools should prepare a crisis response plan to address these losses.  Further disruption to the learning environment should be expected if schools must close down again due to viral activity within the community.