Researchers say COVID-19 could be stopped with even a moderately effective vaccine

Researchers at Weill Cornell Medicine – Qatar and Qatar university have shown that even a moderately effective vaccine could be enough to stop the current coronavirus pandemic.

The study – Epidemiological impact of SARS-CoV-2 vaccination: mathematical modeling analyses – was funded by NPRP grant number 9-040-3-008 and NPRP grant number 12S-0216-190094 from the Qatar National Research Fund, and was conducted by the Infectious Disease Epidemiology Group at WCM-Q in collaboration with Dr. Houssein Ayoub from QU. The study is brand new and yet to be peer-reviewed, but has been released in commitment to the principles set out in the 2016 Statement on Data Sharing in Public Health Emergencies. 

“With several Covid-19 vaccines still in early stages of development, we aimed to provide the scientific evidence that can inform vaccine development, licensure, decision-making, and administration strategies. In this study, we determined the preferred characteristics for COVID-19 vaccines and forecasted their impact at the population-level”, said Dr. Monia Makhoul, co-lead author of the study and postdoctoral research associate at WCM-Q.

Using mathematical modeling of COVID-19 spread in China, the scientists found that a vaccine that reduces susceptibility to contracting the infection by more than 70 per cent is needed to eliminate the infection.

“Even if a vaccine has an efficacy of less than 70 per cent, it could still have a major impact, if individuals who get the infection but are vaccinated, become less infectious or have a faster recovery”, said Dr. Houssein Ayoub, co-lead author of the study and assistant professor in the Department of Mathematics, Statistics, and Physics at QU.

The study also found that infection spread can be controlled with a moderately effective vaccine if used in conjunction with moderate social distancing, or if a significant number of people who were infected during this current wave of the virus become immune.

The team also studied the value-for-money of vaccines and found that even with an efficacy of just 50 per cent, a COVID-19 vaccine could prevent one infection for every 2.4 people vaccinated.

 “For maximum effectiveness, value for money and best use of resources, vaccination strategies should prioritize vaccinating individuals who are 60 years of age or older, or those with co-morbidities, and then gradually provide the vaccine to younger age groups”, said Hiam Chemaitelly, a co-author of the study and senior epidemiologist at WCM-Q.

Dr. Laith Abu-Raddad, leader of the study team and professor of healthcare policy and research, and director of the Biostatistics, Epidemiology, and Biomathematics Research Core at WCM-Q, said: “The results provide room for optimism and the research demonstrates the value and cost-effectiveness that the vaccine will provide. Even a vaccine which works in just 50 per cent of cases would be a game-changer, allowing us to control the infection, save lives, and resume economic and normal life activities.”