Zoe Berg

Amid a nationwide effort to combat the COVID-19 pandemic, researchers at the School of Public Health and the School of Medicine produced some of the biggest breakthroughs. 

As the pandemic impacted daily life at the University, labs at the School of Public Health and School of Medicine pivoted to focus their research on COVID-19. Yale scientists studied characteristics of the virus, developed treatment options and improved testing methods. Yale studies and findings gained national attention.

Much of the research conducted at Yale was made possible by a team of experts who collaborated on a project called Yale IMPACT — a partnership between the School of Medicine, the School of Public Health and the Yale New Haven Hospital. The team aimed to address the demand for COVID-19 patient samples by rapidly building a biorepository, or a bank of materials for researchers to access. Samples were stored in freezers at the School of Public Health or sent to the National Institute of Health, where they were made available to researchers at other institutions. 

In a February interview, Craig Wilen, a member of the IMPACT team and an assistant professor in laboratory medicine and immunobiology, said, “In my career, in science and [in] medicine, I have never seen such a large-scale, organic study be organized so fast.”

Researchers from the School of Public Health also met the demand for testing by developing SalivaDirect, an inexpensive saliva-based COVID-19 test. Once developed at Yale, the test was validated in a collaboration with the NBA. On Aug. 15, 2020, the U.S. Food and Drug Administration (FDA) granted an Emergency Use Authorization for SalivaDirect — making it the fifth saliva sample test and the first testing protocol to receive Emergency Use Authorization from the FDA. 

“Providing this type of flexibility for processing saliva samples to test for COVID-19 infection is groundbreaking in terms of efficiency and avoiding shortages of crucial test components like reagents,” said FDA Commissioner Stephen M. Hahn in an official statement released on Aug. 15.

Another advantage of saliva testing was reported in a paper published on Jan. 6, 2021, by a team led by professor of immunology Akiko Iwasaki. The study found that the viral load from saliva tests might predict the severity of COVID-19 cases more accurately than the viral load from nasopharyngeal tests, also known as nasal swabs.

After developing the saliva test protocol, researchers turned their attention to further reducing testing costs. In April 2021, the team published a paper suggesting that pooled saliva testing could increase testing capacity. The method works by analyzing multiple samples at once — only one test is needed if the whole pool is negative for COVID-19, while the samples will be retested individually if there is a positive result.

“The main reason why we’re interested in this research is to get kids back to school,” Annie Watkins SPH ’21, graduate student and the study’s lead author said in an April interview. “Pooling samples provides a more cost-effective option for screening so that schools can monitor students while bringing them back without too much of a financial burden.”

Other researchers studied viral infection, including the link between sex and COVID-19 infection outcomes. Men appeared to be at a higher risk for severe outcomes than women, so the Iwasaki Lab explored these differences. In a study published on Aug. 26, the lab found significant differences between male and female immune responses to COVID-19, including differences in T-cell activation.

The Iwasaki Lab also collaborated with the Caroline Johnson Lab to explore whether sex differences in metabolism were linked to the differences in immune responses. The study identified a metabolic molecule called kyeurnic acid that was correlated with the immune response in males.

While some researchers worked to better understand the virus, other Yale studies examined current treatments or worked to develop new, more effective ones.

One team at the School of Medicine looked at intermediate dose anticoagulation and aspirin as potential treatment strategies in a study published on Jan. 21. The results were promising, as patients who received an intermediate dose anticoagulation had a higher survival rate than those who did not, as did patients who were given aspirin. Another paper published on Feb. 11 also looked at the efficacy of anticoagulants, finding that patients who were given doses of anticoagulants within 24 hours of being hospitalized had a 30 percent lower mortality rate than patients who did not receive the drug.

While working to develop treatments for COVID-19, the emergence of new variants presented an additional challenge to researchers. A collaboration between the chemistry department and School of Medicine developed a possible COVID-19 drug through a process called molecular sculpting — a method that uses computational tools to quickly modify and test different compounds.  The drug is promising because it targets an enzyme called Mpro, which mutates relatively slowly. This slow mutation means that the enzyme is structurally very similar in new variants, and it should still be vulnerable to the drug.

“It’s very important to have the type of drug that we’re developing because it’s highly likely that it will remain effective against many variants that are evolving,” William Jorgenson, Sterling Professor of Chemistry and one of the study’s authors, explained in a March interview.

As the vaccine rollout began in Connecticut and nationwide, new questions arose about how effective the vaccine would be — particularly in high-risk groups that were left out of clinical trials.

To address these questions, the School of Public Health collaborated with the Center for Disease Control and Prevention and the Connecticut Department of Public Health to look at the effectiveness of vaccines in nursing homes. The resulting study, officially published on March 19, looked at the protection a single dose of the Pfizer vaccine offered to nursing homes residents, a population that had been devastated by the coronavirus.

“This suggests that even one dose of the vaccine does offer significant partial protection against COVID-19, but that to achieve an optimal level of protection in this vulnerable population, we need to be ensuring that everyone is getting two doses,” Hanna Ehrlich SPH ’22, a doctoral student at the School of Public Health and one of the study’s authors said in an April interview.

Other important work by the School of Public Health includes a statistical model called covidestim that tracks positive COVID-19 cases. The model uses previous data to make predictions about the delay in reporting, providing a more accurate estimate of current numbers. Another study published on Oct. 26 examined the psychological consequences of the pandemic for healthcare workers.

Another School of Public Health team collaborated with researchers at the School of Engineering and Applied Science to develop a wearable clip that could detect exposure to COVID-19. The clip aims to help healthcare workers determine their risk of exposure.

During the partnership with the NBA, SalivaDirect analyzed 3,779 saliva samples from players and league associates.

Aislinn Kinsella | aislinn.kinsella@yale.edu