University of Miami study finds flu shots may help against Covid-19
A newly published study created by researchers and physicians from the University of Miami found that the flu vaccine may provide protection against Covid-19, although further studies still need to be done.
Devinder Singh, M.D., chief of plastic surgery and professor of clinical surgery at the Miller School, UM plastic surgery resident Benjamin Slavin, M.D., and UM medical student Susan Taghioff were the authors of the paper that pored over more than 73 million medical records of patients to study the benefits of the influenza vaccine.
The study used an electronic medical record network that included data of anonymous patients in 56 healthcare organizations around the world, including the US, United Kingdom, Italy, Germany, Israel and Singapore, Dr. Slavin told Miami Today. It was a retrospective analysis with data of Covid-19 positive and non-positive patients between January 2020 and January 2021.
“So, what we did was we posed the question: if the patient receives the flu shot within six months to two weeks of testing positive for Covid-19, does it have any sort of potentially protective benefit, in terms of severe effects of Covid-19?” Dr. Slavin said. “With that question we were able to find almost 74 million patients from around the world, so we had two groups of about 37,000 patients in each group,” he continued, one group that had the flu shot and another that did not.
The database allowed UM scientists to balance the groups and have people of diverse gender ages and race, and also factors such as smoking habits, diet, exercise and access to healthcare.
They also opted to include patients who got the flu shot within six to two weeks, since according to the Center for Disease Control (CDC) it takes about two weeks for the flu vaccine to reach its full effect and it lasts for about six months before there is any type of a waning or a decrease in the effectiveness of the protection, Dr. Slavin explained.
What UM researchers then found when comparing the data between the two groups of patients was that individuals who had received the flu vaccine and tested positive for covid “had significantly less emergency room visits, ICU visits, less incidences of sepsis or blood infection, as well as less stroke, and less DVT, or deep vein thrombosis,” Dr. Slavin said.
They also calculated a number needed to vaccinate to determine the average number of patients who needed to be up-to-date on their influenza vaccination in order to have prevented one adverse Covid-19 related outcome. “For example, for every 286 covid-positive people who receive their flu shot, one person avoided being diagnosed with sepsis or contracting sepsis,” Mr. Slavin explained.
But although the results are “exciting” and “encouraging,” Dr. Slavin was emphatic that the “Covid-19 vaccine is the most important thing that you can get. The flu shot is in no way, shape or form any type of a substitute for the Covid-19 vaccine. That is the gold standard to protect yourself.”
He pointed out that the CDC suggests that it’s totally safe to get the influenza vaccine as well as your covid vaccine; but warns that people should always consult with their healthcare providers.
UM researchers now consider that a prospective study should be performed.
“Prospective meaning moving forward,” Dr. Slavin said. “Starting the study, enrolling patients, controlling the patients with follow-up appointments and lab tests.”
The motivation to start the study, Dr. Slavin explained, was the very diverse patients at UM. “We’re really fortunate and blessed as physician scientists at the University of Miami to serve an extremely diverse patient population that presents with unbelievable pathologies from all over the world,” he said. Thus, that ultimately motivated this study is in terms of countries included.
Moreover, an aim was to generate literature that could lead to further research and that could determine if the influenza vaccine really provides protection against coronavirus. “The influenza vaccine is something that is relatively widely available,” Dr. Slavin said.
“By being able to take this data and pose that question, and see if there might be some benefit,” he said, “would allow countries that many of our patients come from or encourage their people to get their influenza vaccine while they [countries] continue to work on the rollout of the covid vaccine.”