Several hundred people in the isles have still not responded to any communication about Covid vaccination, health officials have warned.
Over 100 people are self isolating as contacts following the outbreak of coronavirus cases over recent days.
NHS Shetland has warned more people may still become positive over the next week.
More than a dozen cases have emerged since the weekend.
On Monday education officials urged parents of pupils in P3-P7 at Mossbank Primary School to keep their children at home.
NHS Shetland’s interim director of public health Dr Susan Laidlaw said: “We still have over 100 people isolating as contacts of recent cases, and it is possible that more people may still become positive over the next week or so.
“The number of cases in Scotland continues to increase, and it is likely that we will see more cases appearing as people travel back and forwards from Shetland.
“But if people continue to follow all the guidance, including use of LFD tests, this does enable us to identify cases earlier and minimise the risk of spread within the community.”
She added: “We know there are still several hundred people who apparently live in Shetland but have not responded to any communications about vaccination.
“This may be due to change or address or phone number, or people not wanting the vaccine.
“Please let us know if you want the vaccination and have not yet heard anything by phoning 01595 743319.
“It would also be really helpful to know if you do not want it so we can stop trying to contact you. And if you have an NHS Shetland letter delivered for someone who has moved away, please return to sender.”