Some were wearing hazmat suits and face masks, while others carried Scotland flags and homemade banners.
They were urging anyone travelling into Scotland from England not to cross the border.
A banner being held by one protester read: “Staycation: Keep Scotland Covid free”.
A Police Scotland spokesperson said: “Police in the Borders were called to a layby area near the A1 at Lamberton at around 2.25pm on Saturday, 4 July, 2020 following a report of protest activity at the side of the carriageway.
“Officers attended and suitable advice has been given to those in attendance.”
The demonstration has attracted widespread criticism from politicians in Scotland, with Scottish Conservative leader Jackson Carlaw describing the scenes as ‘shocking and inexcusable’.
A Scottish Government spokesperson said: “We condemn this type of behaviour in the strongest possible terms. This is an isolated incident and not indicative of the vast majority of people’s views.”