Regina Sung, Photo Editor

Researchers from the Yale School of Public Health published a study modeling the number of deaths and hospitalizations that could be prevented by accelerating the pace of vaccination against COVID-19. Across the 10 states included in the study, the researchers found that 19,500 hospitalizations and 6,900 deaths could be averted through March 2022 by increasing daily vaccination rates by 50 percent starting in September.

Epidemiology professor Alison Galvani and associate research scientist Pratha Sah both worked on the paper, published Oct. 5 in the Commonwealth Fund. The team used a previously-developed computational model to project the number of hospitalizations and deaths that would occur over the next six months if statewide vaccination rates increased by 50 percent, and then compared this number to a projection if the vaccination rate holds steady. Galvani and Sah were among the paper’s authors, alongside Eric Schneider, senior vice president for policy and research at the Commonwealth Fund.

“Recently, states with lower vaccination rates have seen much higher rates of hospitalizations and deaths compared to those with higher vaccination rates,” Schneider wrote in an email to the News. “We wanted to quantify the potential benefit of accelerating the pace of vaccination in states with both low and high rates of vaccination.”

In the study, the researchers looked at five northern states with upward trends in daily infections and five southern states with declining trends that have already reached their peak. They simulated two different scenarios: one scenario modeled a 50 percent increase in daily administered doses compared to the final week of August, while the other scenario modeled this number remaining constant. The projected infections, hospitalizations and deaths due to COVID-19 between the two simulations were compared, and the difference between the two was reported as the number of deaths and hospitalizations that could be potentially averted.

On a state level, the highest number of averted hospitalizations projected was 5,056 in Texas, and the most averted deaths projected was 1,441 in Florida. New Hampshire had the smallest projected impact for both measures, with 10 deaths and 65 hospitalizations averted in the model. According to Sah, this analysis will be expanded in the future to include the entire United States. 

While similar studies have covered vaccination efforts taken thus far and simulated what could have occurred differently, this work looked ahead to demonstrate the potential impact of current and future interventions. Additionally, the researchers explained the feasibility of the simulated 50 percent increase in vaccinations, and pointed out that vaccination mandates have been effective in the face of vaccine hesitancy.

“Accelerating the pace of vaccinations would prevent a significant number of hospitalizations and deaths from the continued Delta wave,” Sah wrote in an email to the News. “With the ongoing threat that new highly transmissible variants will emerge, increasing vaccination pace now is critical.”

Director of the Yale Institute for Global Health Saad Omer spoke to the study’s usefulness, particularly as a way to demonstrate the human cost of insufficient interventions. 

Omer also detailed strategies that policymakers can implement to encourage vaccination and reduce the  virus’ spread. He emphasized that vaccination mandates for travel could be an effective way to reduce the spread of the virus in anticipation of the holiday season, and he noted that personal physicians can be influential figures in nationwide vaccination efforts.

“We need to have a national program to train healthcare providers, who remain the most trusted source of vaccine information from the beginning of this outbreak through now, to empower them with evidence-based approaches to communicate around vaccines,” Omer said.

Sah said that vaccination rates could be increased by improving confidence in vaccines in communities that have low vaccination rates, as well as by making vaccine appointments more accessible. She added that financial incentive programs have been shown to increase vaccination rates, and that private companies can boost vaccinations by enforcing their own mandates for employees. 

The researchers obtained daily vaccination data for each state from the Centers for Disease Control and Prevention. The model was calibrated with reported incidences from Oct. 1, 2020 to Aug. 31, 2021 in order to simulate the impact from Sept. 1, 2021 through Mar. 31, 2022.

According to Sah, the model used current information about vaccine effectiveness and did not account for potential changes in the landscape of SARS-CoV-2 variants. The possibility of new variants emerging could interfere with these numbers, and highly transmissible ones could further increase the need for vaccinations.

“[Because] vaccines are available, the future of the pandemic is not written in stone,” Schneider wrote. “It can be improved by even modest increases in vaccination.”
According to the CDC, 56.4 percent of the United States population is fully vaccinated as of Oct. 9, 2021.