Previous research has found that older people are less likely to use social media than younger generations. As evidence suggests that younger people can influence the health behaviour of older relatives offline, we set out to test whether social media could be used to engage older people via their younger relatives using a large-scale targeted social media advertising campaign.

After reaching over a million people and generating over 5 million impressions, we found that:

• Despite popular stereotypes to the contrary, targeting older users directly on social media is a more effective way of encouraging them to get their jabs than engaging them indirectly through younger people.
• Social media adverts are a cost-effective way of encouraging marginalised older adults to get their flu jab.
• Our campaigns focussed on the pneumococcal vaccine had an even greater and cost less than a third of the price per booking link click than the flu adverts.

Based on the success of this campaign, we’re calling for the Government and NHS to invest more in targeted social media campaigns to improve uptake among those who need their jabs most, and those who are least likely to get them otherwise.