According to Ministry of Health data numbers of Covid-19 tests in the Southern District Health board area dropped from 4905 in the week from August 23 to August 29 to 1697 last week.
Dr Jack stressed there was still a risk Covid-19 could make it into Otago and Southland.
"The borders are well managed, but are not watertight, Covid is a tricky virus and we can't be complacent so Covid-19 testing is extremely important to ensure there is no community transmission in the district.
She also stressed the importance of people following Level 2 rules.
"We know the Delta strain is highly infectious, and can spread by airborne transmission to infect someone within seconds.
"So please wear a mask when you leave the house where you can't distance, when you are in the premises where a mask is required under Alert Level 2, remember to scan everywhere you go, and don't forget the importance of good hand hygiene."
Dr Jack is also urging anyone who is eligible and who has not yet been vaccinated to book their first vaccination this week.
"So far 78.3% of eligible Southern residents have had their first dose of the vaccine, and 43.5% are fully vaccinated.
"Southerners have done a fantastic job in getting vaccinated but we need everyone who is eligible to do their bit and have the vaccine so we can get to 90% or higher as soon as possible.
She said summer was around the corner and increased vaccinations would allow people to enjoy events like festivals.
"Young people, please go and get vaccinated if you already haven't. You still have a bit more vaccinating to do to catch up with our older people, so if we all want to move down alert levels and enjoy summer events, the best thing you can do is get vaccinated now."
She also praised the efforts of providers in the South for the vaccine roll-out so far.
"Our vaccination rates are one of the best in the country, and this has only been made possible by the hard work of more than 110 providers."
These providers included general practices, pharmacies and Māori and Pacific health agencies.
