The dose21:56What is the latest flu vaccine?
With flu season fast approaching, people who haven’t been vaccinated against COVID-19 or who qualify for a third dose can safely get vaccinations to protect against both diseases in the same visit, health experts say.
They believe that in the future, by applying the latest advances in mRNA technology, it may be possible to vaccinate a person against COVID-19 and the seasonal flu with a single vaccine.
That’s because even before the pandemic, vaccine developers were working on developing influenza vaccines using mRNA technology used in the Pfizer-BioNTech and Moderna COVID-19 vaccines, said Susy Hota, medical director for infection prevention and control at the University Health Network in Toronto.
Some are already in the clinical trial stage.
No combination vaccine against COVID-19 and flu has come this far.
Hota says it would be incredibly handy to use mRNA technology to better protect people from the flu.
“What the future could bring is a single combined vaccine that fights multiple infections that are circulating at the same time. So that could be COVID 19 and influenza,” she told Dr. Brian Goldman, presenter for CBC Radio’s The dose Podcast.
“We’re not there yet. But wouldn’t it be nice to come over for your only respiratory virus injection to cover you for this season?”
Flu viruses often mutate as they circulate around the world, Hota said. By the time scientists see which tribes take off in the southern hemisphere and predict which flu vaccines to use for people in the northern hemisphere, there could be discrepancies.
On average, flu vaccines protect about 40 to 60 percent against infection, said Hota.
Because people infected with flu are at higher risk of heart attacks and other heart problems than the general population, flu shots save lives, she said.
“If we saw too many COVID-19 and influenza patients come into our hospitals, it could cripple the system,” she said.
Speed is key to defeating the flu
Vaccine manufacturers are trying to catch up with the mutating virus so that what’s in their vials will better match the strains of flu we might encounter from others the cough or maybe talk a little too close.
This is where mRNA technology comes into play. Experts say they could perhaps monitor flu activity around the world for extended periods of time and then use the speed of mRNA vaccine production to add circulating flu strains to vaccines in a timely manner to better protect the public.
Scott Halperin, a pediatric infectious disease specialist and professor at Dalhousie University in Halifax, leads clinical trials for influenza and other vaccines at the Canadian Center for Vaccinology in Halifax.
He says mRNA technology could likely speed up flu vaccine production compared to the time-consuming approach of growing the virus in chicken eggs as is used today.
At least three companies say they are starting phase 1 human safety studies with mRNA-only flu vaccines to see if the side effects are similar to traditional flu vaccines, such as arm pain or fever.
In order to finally combine COVID-19 and flu protection in one vaccination, the researchers must first test whether the mRNA technology can be safely and effectively applied to influenza viruses.
New technology brings better immunity
Moderna and Pfizer’s mRNA vaccines against COVID-19 contain the genetic instructions to make a modified spike protein from the virus. Once the vaccine is injected into the body, human cells use the instructions to make copies of the spike protein so the immune system learns to recognize it.
For the three seasonal influenza mRNA vaccines in clinical trials, companies must show that combining strains of flu in this way does not reduce the effectiveness of the immune response in front of regulators like Health Canada Consider approval.
Alyson Kelvin, a scientist at the University of Saskatchewan’s Vaccine and Infectious Disease Organization (VIDO), has studied various flu vaccines for years and is also working on COVID-19 vaccine candidates.
“It seems we have this nice, broader immunity through mRNA vaccine technology,” Kelvin said. “Could you somehow target more than one strain of influenza at a time?”
Even if the answer is yes, Kelvin said, it is a leap from using a spike protein from SARS-CoV-2, the coronavirus that causes COVID-19, to also cover four circulating strains of influenza virus, as is the case with the Current flu shots do it with a single shot.
“It’s exciting, but I think we really need to close the investigation,” said Kelvin. The all-in-one flu and COVID-19 vaccination studies have not reached human clinical trials that typically take years.
Researchers recognize that better flu vaccination strategies are needed to get more protective responses, she said.
Until then, public health officials hope that people will continue to wear masks and wash their hands when necessary to protect themselves from any pathogens that affect people of all ages during the respiratory virus season.