The novel coronavirus vaccination efforts in France might face opposition from anti-vaxxers as around 30 percent of working-age adults in the country are 'outright opposed' to getting the shots, revealed a survey.

Such a widespread distrust towards new vaccines could hamper the target of achieving herd immunity to prevent the transmission of the virus, researchers warned in a study published in The Lancet Public Health journal.

Researchers suggest that herd immunity can be reached if 60 percent of a country's population becomes immune to the virus through infection or vaccination. Still, people will have to continue following preventive measures during the vaccination drive, including physical distancing and using masks to control the infection rate.

But more than 70 percent of the population is ready to get inoculated if the vaccine is effective and comes from a reliable source, the study added. 

The European Union's health regulator European Medicines Agency (EMA), has approved three COVID-19 vaccines—Moderna, AstraZeneca and Pfizer-BioNTech—for mass immunization.

The study surveyed 1,942 adults in France aged 18-64 years in July – when lockdown restrictions had been eased–using a two-part online questionnaire. The first section captured background information such as participants' past vaccination experience and their risk of having a severe case of COVID-19.

In the second part, participants were asked to select a vaccine based on its efficacy, side effects, country of manufacturer, and vaccination sites like local pharmacies, mass vaccination centers, or a local doctor.

"We used a study design that allowed us to separate people into two groups: those who will accept vaccination depending on its characteristics, and those who would always refuse one," said Dr. Verity Watson, of the University of Aberdeen.

"This information is important for designing mass vaccination campaigns because it shows how sensitive uptake is to the design of the campaign. Opinion polls are rarely able to separate people in this way."

A series of incidents in the last few decades triggered mistrust on vaccines in France. Most prominent among them were: hepatitis B vaccination of children coinciding with the rising number of sclerosis cases, distribution of blood products contaminated with HIV to hemophiliacs and over the purchase of H1N1 vaccines.

In the case of hepatitis vaccination and sclerosis, studies couldn't find a link between them.

With a considerable population skeptical about COVID-19 vaccines, researchers have recommended that the government use vaccines with robust evidence of high levels of effectiveness.

The use of vaccines manufactured in the U.S. or the European Union, and emphasizing the collective benefits of herd immunity during mass immunization drive, could help achieve herd immunity.

(Cover: An empty booth is seen at a vaccination center in the city hall of the 17th district in Paris, which was not allowed to open because of a COVID-19 vaccines shortage in France, January 29, 2021. /Reuters)