It’s been six months since the race to develop a COVID-19 vaccine began, but according to most experts, we’re still at least 12 months away from that ultimate goal.
In the meantime, the polio vaccine is gaining more attention as a temporary solution. Extensive evidence already exists to prove that the polio vaccine is safe, affordable, and easy to distribute. In fact, more than 1 billion doses are currently produced annually in 140 countries worldwide.
A team of researchers led by Konstanin Chumakov published a report in Science Magazine on June 12 explaining the value they see in the polio vaccine and how it could be harnessed in the fight against COVID-19.
Do Live Attenuated Vaccines Hold the Key?
There are two main forms of vaccines used to immunize children and adults. Inactivated vaccines use virus particles that have been killed, while attenuated virus vaccines use live viruses with substantially reduced virulence.
It’s been well established that these two types of vaccines induce “adaptive and generally long-term and specific immunity in the form of neutralizing antibodies and/or activating pathogen-specific cellular immune responses,” the researchers write. But they also cite increasing evidence that attenuated vaccines may provide broader protection against unrelated pathogens.
“The stimulation of innate immunity by live attenuated vaccines in general, and oral polio vaccine (OPV) in particular, could provide temporary protection against coronavirus disease 2019.”
The History of the Polio Vaccine
The polio vaccine was developed in the 1950s in response to the polio epidemic affecting children at the time. The vaccine is formulated with live attenuated polioviruses of three serotypes.
The clinical studies demonstrated OPV’s strong protective nature against poliomyelitis. Results also indicated that OPV, when compared to placebo, reduced the number of other viruses that could be isolated from immunized children. Large-scale clinical trials performed years later showed that OPV was effective against influenza virus infection, genital herpes simplex virus infections, and others.
Using OPV To Fight COVID-19
Based on evidence that COVID-19 results in suppressed innate immune responses in patients, experts now believe that live attenuated vaccines may effectively increase resistance to infection by SARS-CoV-2. Clinical studies are already taking place to test this hypothesis.
As a result, the authors of the article in Science Magazine propose “the use of OPV to ameliorate or prevent COVID-19.” They cite many importance safety factors in support of their proposal, including the facts that OPV:
- Has a strong safety record dating back decades
- Uses more than one serotype, which could be used sequentially to prolong protection
- Can be easily administered at a low cost
- Has proven a very low risk of complications
According to the authors, this idea has important implications for future epidemics and pandemics as well. “If proven to be effective against COVID-19, emergency immunization with live attenuated vaccines could be used for protection against other unrelated emerging pathogens.”