November 3, 2021 - Podcast

Episode 198—AstraZeneca vaccine efficacy, and parents’ reluctance to vaccinate children

As the battle against COVID-19 continues, vaccinations remain vital. Although it’s not yet approved for use in the United States, the AstraZeneca COVID-19 vaccine is one of the predominant vaccines used around the world, with more than a billion doses administered. Now, a recently published study confirms that the AstraZeneca vaccine is safe and effective in preventing symptomatic and severe COVID-19 among adults in the United States. The Indiana University School of Medicine was one of more than 80 sites conducting a portion of the study, which was published in the New England Journal of Medicine. Dr. Cynthia Brown, an associate professor of clinical medicine who led the study at IU, says the IU School of Medicine was one of the largest enrolling centers around the country. Out of the more than 32,000 adults who participated, more than 500 study participants came from Indiana. The study’s results showed a 74% efficacy rate overall for the two-dose vaccine and an 83.5% efficacy rate for participants 65 and older. The study’s finding about older adults is further supported by real-world data from the United Kingdom that also shows high vaccine effectiveness for prevention of COVID-19 in older adults after the first AstraZeneca vaccine dose. Brown says the new study should improve confidence about the AstraZeneca vaccine’s effectiveness, both in the United States and worldwide.

In other news, while many parents are eager for their children to get a COVID-19 vaccine, a substantial number remain uncertain, says Jessica Calarco, a social scientist at IU Bloomington. Politics and misinformation have influenced the choices of many parents, but Calarco says that’s not the only reason for their vaccine reluctance. She says her research suggests parents do not feel urgency about getting children vaccinated because during much of the pandemic, public health and media messaging reassured them that children were at low risk from COVID-19, leading them to view COVID-19 vaccines as unnecessary. Once parents view vaccination as unnecessary for their kids, Calarco says, they can also become more susceptible to misinformation about vaccine risks. Mothers especially may be susceptible to such misinformation because of the pressure they feel to keep their children safe. False and exaggerated claims about the vaccine risks can fuel their maternal fears, Calarco says. Public health experts and the media have a key role to play in persuading parents to vaccinate children, Calarco says. For example, the risks COVID-19 poses to children and the risks unvaccinated children pose to people around them, including vaccinated adults, should be made clear. Calarco says if we want to end the pandemic, then all of us—including parents of young children—need to look beyond a focus on individual responsibilities and choices to consider how widespread vaccination of children can help protect others.