As rates of vaccination increase in populations around the world, another barrier presents itself in the fight against COVID-19: second dose hesitancy.
In April 2021, The New York Times reported that 8 per cent of Americans missed their second dose appointment, according to the Centre for Disease Control. The report outlines several reasons behind the no-shows, including a fear of possible side effects, overconfidence in the first shot, and a lack of supply for certain brands of the vaccine.
After a slow start, Canada has officially surpassed the United States in vaccination rates for residents who are fully vaccinated. However, despite the promising increase, Dr. Rob Kozak, clinical microbiologist and scientist at Sunnybrook says we must remain diligent.
“The worst thing that could happen would be for Canadians to refuse or delay getting vaccinated. This will lead to it taking longer to get population level immunity,” he says.
Dr. Kozak offers insight on common concerns surrounding second doses, and why getting fully vaccinated is the best way to protect yourself and the people you love.
Improvement of overall efficacy
“There are so many reasons to get both doses,” Dr. Kozak says. “The second dose of the vaccine is important for building immune memory, and robust antibody and T-cell response against the variants.”
Having both doses of the vaccine also increases overall efficacy, meaning your chance of having an infection is reduced, Dr. Kozak adds.
Furthermore, he says, if you do get infected with the virus, you are more likely to have a milder case, and less likely to spread it to those close to you when you are fully vaccinated.
Increased protection against variants
“There is data coming out that is showing that one dose provides much more limited protection against variants,” Dr. Kozak says.
As the contagious Delta variant continues to increase in prevalence across Canada, you can put yourself at risk by not getting the second dose.
“Plus, we will likely see more variants emerging in the future, and so far all our data is showing that 2 doses is more protective against variants than a single dose,” he says.
Necessary to achieve herd immunity
Herd immunity occurs when enough people have a protective immune response against the virus that will prevent them from getting very sick and reduces the chance of the virus spreading to others. In order to achieve herd immunity, Dr. Kozak says viruses needs a susceptible host to replicate and spread to others.
However, he notes that we cannot solely rely on others around us to be have their shots. In order to protect those who are more vulnerable to infections, we must also ensure we are doing our part.
“It is important to remember that the vaccine will not work perfectly in everyone. For example people who are immunocompromised may not be as well protected if they are vaccinated, and they are relying on all of us to get our shots to help keep them protected,” he says.
By continuing to increase the vaccination rate, we can all contribute to a healthier future. Of this, Dr. Kozak remains optimistic.
“This pandemic has been hard on everyone, but now we can see an end in sight.”
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