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Understanding COVID-19: Vaccine Distribution Challenges

A year into the COVID-19 pandemic, the approval of not only one but several effective vaccines has given us reason to be hopeful. But we now face a new set of logistical and ethical challenges in our unprecedented effort to inoculate the global population. “This is the largest mass vaccination campaign and the most rapid one in human history,” says Andrew Heinrich, a lecturer at the Yale School of Public Health. “And that creates supply chain challenges and distribution challenges.” The first hurdle standing between these life-saving vaccines and the general public are a myriad of supply chain complexities – from manufacturing to transportation to storage. Although significant, these supply chain issues are all surmountable, says viral epidemiologist and Director of the Yale Institute for Global Health, Dr. Saad B. Omer. The larger concern is that these supply chain constraints make it impossible for us to vaccinate everyone at once. Which means we must make strategic and equitable decisions about who to vaccinate first. “We are in a position where it’s necessary to decide who to vaccinate first and all of humanity is benefited when those at greatest risk get vaccinated first,” says Heinrich. Watch this video to learn more about overcoming distribution challenges and how equity plays a crucial role in determining the success of the COVID-19 vaccine rollout.


When the novel coronavirus COVID-19 first appeared in late December 2019, scientists at the Yale School of Public Health responded immediately to help shape the world’s public health response. Our experts in transmission, genetics, vaccines, social behaviors, modeling, health policy and global health and justice not only have been at the forefront of scientific discovery, but they have made it a priority to inform the public through media appearances, op-ed pieces, consulting, town halls and other forums.

As this historic pandemic has unfolded in real time, our work at the Yale School of Public Health has never been more relevant or impactful. Our global influence has taken the form of research, public education and public service.


  • Invention of the SalivaDirect™ procedure, a more affordable and convenient COVID test.
  • Molecular tracking (modeling) of the virus for the Connecticut Department of Public Health and the CDC, including recognition of the first U.K. variants in the Northeast.
  • Discovery of a likely metabolic difference between men and women that possibly explains the worse outcomes in men, opening up a new therapeutic research option.
  • Development of the COVID-19 Hospital Capacity Model app to model utilization of ICU and floor beds, as well as patient deaths due to COVID-19. It was developed by the COVID-19 Statistics, Policy modeling and Epidemiology Collective (C-SPEC).
  • Mathematical modeling that framed the university response of twice-a-week routine testing that helped keep Yale and many other schools safe.
  • YSPH faculty advise Yale’s COVID Public Health Committee, among others, assisting with analysis, policy decisions and communications.
  • Collaboration with the Yale School of Engineering to use sewage for COVID surveillance.
  • Collaboration with the Yale School of Medicine to run a large cohort and specimen repository to permit fundamental discoveries in virology, immunology. and clinical management.
  • Research on air pollution reductions during COVID-19 lockdowns and meterological factors and COVID-19.

Public Education

  • YSPH faculty and alumni are serving on President Biden’s White House Task Force for COVID-19.
  • YSPH faculty are serving on (and co-chairing) the ReOpen CT Advisory Group for Governor Ned Lamont; staffing the Connecticut Academy of Science and Engineering’s CASE Paper: “An Adaptive Risk-Based Strategy for Connecticut’s Ongoing COVID-19 Response”; and staffing the Governor’s COVID Vaccine Advisory Group.
  • Extensive service to the public schools (especially Bridgeport, New Haven and New York City) and private schools (members of the Connecticut Association of Independent Schools and the Sacred Heart Schools).
  • Extensive service to arts organizations in the state through the Reopening CT Arts Venues: Science-Based Safety program in coordination with the Shoreline Arts Alliance to explore and deliver science-based information to inspire both artist and consumer confidence, and to ensure economic success and long-term viability.
  • Consultation with mental health providers, primary care practitioners, hospice care venues, homeless shelters and nursing homes for staff education and risk mitigation.
  • Partnerships with a wide array of media for public education, including a modeling collaboration with The Washington Post.
  • International, national and local education on COVID-19 vaccines and how to address vaccine hesitancy.
  • Holding dozens of Rotary and alumni webinars in Connecticut, New York, Rhode Island, Kentucky, California and Minnesota, reaching more than 10,000 participants.
  • Provided guidance to the New Haven Health Department for volunteer guidelines and school-reopening planning.
  • Crafted an online resource for middle-school students to better understand public health and the current COVID-19 epidemic.

Practice and community-based research and initiatives

  • Contact tracing: In March-July, YSPH provided contact tracing for the greater Yale community and for the city of New Haven, which served as a model for the state of Connecticut. Since August, we have continued contact tracing for the greater Yale community; originally anchored by more than 200 part-time volunteers (a majority were students), it’s now overseen by 11 full-time employees.
  • Outbreak investigation: Since November, providing outbreak investigation services for the members of the greater Yale community who often engage the Greater New Haven region.
  • At least 14 school walk-throughs for risk mitigation and staff education, including indoor air-quality engineering decisions.
  • Co-founded an effort with Volunteer Surge to serve food banks, shut-in elderly and shut-in veterans, the homeless and the unemployed.
  • Volunteer coordination: In partnership with the United Way of Greater New Haven, met urgent community organization needs through more than 2,500 volunteer hours. Most notably, the Community Alliance for Research and Engagement (CARE) served as a vital partner in the development of a rapid-response effort through Pantry2Pantry, which reached up to 1,000 households through a grocery-delivery service from May-August. YSPH Office of Public Health Practice (OPHP) networked with other universities in New Haven to direct volunteers (students, faculty and staff) to the United Way to meet these needs.
  • Scaffolding (OPHP) and financially supporting (Grubaugh Lab) a testing strategy utilizing SalivaDirect™ for the entire Learning Hub network in New Haven; will test all staff of the Learning Hubs in partnership with the YMCA for a 10-week mini-program (10 weeks x 100 tests per week).
  • Supporting the expansion of testing to include SalivaDirect™ in New Haven. Grubaugh Lab is funding YPL to do this and OPHP is assisting with operations; this will begin with the current community sites.
  • Members of YSPH are serving on the COVID Risk Communication Committee run by the New Haven Health Department. Chandra Kelsey serves on the group 65+ and their caregivers.

Global Health

  • YSPH faculty on the World Health Organization’s Emergency Committee on COVID-19 are providing key guidance for vaccine strategy for low- and middle-income nations.
  • We have led professional education webinars on COVID-19 with academic and ministry of health colleagues in Burkina Faso, Senegal, Ghana, Uganda, Chad, Sudan, Burundi, South Africa and China, among others.


On August 15, 2020, the FDA authorized YSPH to officially designate qualified CLIA-certified laboratories to run the SalivaDirect™ Test. Since then, 405 laboratories have requested designation under our emergency use authorization (EUA). As of January 30, 2021, we have initiated the designation process with 318 of these laboratories and streamlined the designation process so that it now takes on average 3-5 days from the time a laboratory submits all required documentation and CLIA verification data.

  • To date, we have deployed the SalivaDirect™ Test to, and officially designated, 91 CLIA laboratory sites under our EUA. These laboratories, comprising university, public health, county hospital, federal, state and private entities, are spread over 33 states and have a self-reported projected testing capacity of more than 250,000 tests per day. (Many are still ramping up their operations and have yet to reach this target capacity.)
  • YSPH alumni Kaakpema and Sara Yelpaala are working with Yale Law School alumni Mike Johnston and Eric Parrie on Colorado’s largest statewide testing initiative: COVID Check Colorado. They are utilizing SalivaDirect™ to not only make testing available for vulnerable populations at scale, but also will be working on access to vaccinations in the state this month.
  • Through a recent partnership with industry, we are now working on developing future iterations of the test, including an at-home collection kit and a combined COVID-Flu testing assay. We’re continually updating our EUA protocol to help labs utilize their existing supply chains and infrastructure, as well as in response to suggestions that will improve access to affordable testing.
  • The University of Illinois has developed another saliva assay, and we have assisted them with technical support.

Covid-19 Research Awards

  • Kai Chen, EHS, ECI award for his paper published in Nature Communications entitled “Role of Meteorological factors in the transmission of SARS-COV-2 in the United States
  • Tyler Shelby, Xin Zhou, Donna Spiegelman, Lauretta Grau, Linda Niccolai and Luke Davis, EMD, Team Award, published in Frontiers in Public Health entitled “Lessons learned from covid-19 contact tracing during a public health emergency: prospective implementation study
  • David Paltiel and Jason Schwartz, HPM, Covid-19 prize, published in Annals of Internal Medicine entitled “Assessing COVID-19 prevention strategies to permit the safe opening of residential colleges in Fall 2021
  • Chantal Vogels, Albert Ko, Saad Omer, Nate Grubaugh and others, EMD, Covid-19 prize published in Nature entitled “Impact of circulating SARS-CoV-2 variants on mRNA vaccine-induced immunity
  • Yusuf Ransome, SBS, Health Equity Prize, published in Journal of Urban Health entitled “Neighborhood social cohesion and inequalities in covid-19 diagnosis rates by area-level black/African American racial composition