Members of the public think the Covid-19 vaccine is most effective nine months after vaccination and fail to consider waning immunity, which could have implications for the uptake of boosters, according to research by the Economic and Social Research Institute (ESRI).
It surveyed a representative sample of 2,000 people in relation to a hypothetical scenario in which 100 people died from Covid-19. They were asked to estimate how many people they thought would have survived if they had been vaccinated two weeks ago, three months ago, six months ago or nine months ago.
The researchers found participants underestimated the efficacy of vaccines against preventing death, with an average response of 68 surviving.
However, despite documented vaccine waning effects, the researchers also found there was no difference in survival rate estimates between those who were presented with the options of three months after vaccination versus six months after vaccination.
“Those who were told the 100 were vaccinated nine months before exposure judged that significantly more would survive. Although vaccine efficacy declines over time, people think that vaccines are most effective nine months post-vaccination,” the report states.
Prof Pete Lunn, head of the Behavioural Research Unit at the ESRI, said the experiment showed there are “really strong misconceptions” about the effectiveness of the vaccine, and how long that effectiveness lasts.
“The two things that are of interest there is that people are underestimating how effective vaccines are at preventing death, and secondly, they gave no weight at all to how long ago they had the most recent dose. We know the vaccines wane over time, quite strongly after about four to six months, and the public, based on that experiment, have not absorbed that message at all,” he said.
“The suggestion would be that one of the reasons we see low willingness to take up boosters compared to what we’ve seen when getting vaccinated initially is because people don’t understand those things.”
Prof Lunn said despite these misconceptions, the “vast majority” of people are still willing to get vaccinated, though the number is not as high as it once was. In May, about 82 per cent of people surveyed said they were willing to be vaccinated, according to ESRI research.
“People’s willingness to be vaccinated does depend on their general level of worry and that level of worry changes. When hospitalisations and ICU admissions start to climb at any point, we start to see willingness to get the vaccine climb too,” he added.
Prof Lunn was speaking following the Government’s announcement it is to expand the booster vaccination programme, with second booster doses to be offered to people aged 50-64, and those aged 12-49 who have underlying medical conditions or live in long-term care facilities.
Healthcare workers and pregnant women will also be offered a second mRNA booster vaccine, while the over-65s and those who are immunocompromised and aged 12-64 will be offered a third booster dose, under the new changes.
