The Military Command of Nghe An Province said Friday that 68 more troops have been sent to border guard posts and would reach latest by Sunday.
The central province has 34 posts and 22 stations with more than 200 troops.
Quang Tri Province has added 172 personnel to the 425 officials and soldiers who currently man 86 posts.
In Thua Thien Hue Province, 38 more soldiers have been added to the 241 already on duty.
Besides manning the posts and stations, the border guards also patrol the border round the clock, including remote trails.
The Vietnam-Laos border runs 2,161 kilometers (1,342 miles) across 10 northern and central provinces.
The number of Covid-19 cases has been steadily increasing in Laos, peaking at 100 a day.
On Friday, the country with a population of around 7.2 million recorded 85 new cases, taking its total number so far to 757.
Epidemiological investigations show that the new infections are closely connected to illegal entrants from Thailand.
In the capital Vientiane, central hospitals are full of patients, requiring field medical facilities to be mobilized. The country has not recorded any deaths so far due to the pandemic.
The country closed its borders and imposed a two-week lockdown in Vientiane more than a week ago.
For the last few months Vietnam’s National Steering Committee for Covid-19 Prevention and Control and Ministry of Health have been warning about the threat of a new outbreak as people have lowered their guard and many are entering the country illegally to avoid tests and quarantine.
Everyone entering from abroad must be quarantined for 14 days and tested at least twice.
After over a month without community transmission Vietnam has recorded 13 new local cases since Thursday, starting with a Vietnamese worker returning from Japan who tested positive two days after completing his two-week quarantine.