A "large majority" of 62 passengers on two flights from South Africa who tested positive for COVID-19 shortly after arrival in the Netherlands on November 26 had been vaccinated, Dutch authorities said on Thursday.
Under rules in place at the time, passengers were able to board the flight from Johannesburg and Cape Town with either proof of vaccination or negative COVID-19 test results.
Meanwhile, health authorities said that more than 20 passengers who have been in quarantine since testing positive will be allowed to leave on Thursday.
A spokesman for the health authority for Kennemerland, in which Schiphol airport is situated, said authorities will not disclose whether any of the 14 passengers found to be infected with the Omicron variant of the virus are being released, citing privacy reasons.
They will also not disclose or discuss the seriousness of those patients' symptoms, the spokesman added, also citing privacy reasons.
The GGD tested more than 600 passengers who arrived on two flights that had departed from Johannesburg and Cape Town on Friday, before the Dutch government changed its rules on air traffic from southern Africa because of concerns over the Omicron variant.
Of 62 passengers who tested positive for COVID-19, 44 were held in isolation in a hotel near Schiphol airport, while some Dutch citizens have been in quarantine at home.
Results of follow-up tests on Monday mean that more than half of those who had been held at the hotel are now free to continue their travels, a GGD statement said.
"Persons that tested positive will remain in isolation. Their situation varies... some have symptoms, others don't or barely," GGD Kennemerland director Bert van Velden said in a statement.
The discovery of Omicron, dubbed a "variant of concern" by the World Health Organisation, has sparked worries around the world that it could resist vaccinations and prolong the COVID-19 pandemic.
Dutch health authorities are also trying to contact and test about 5,000 other passengers who have travelled from countries in southern Africa since November 20. Those tests have so far discovered two additional Omicron cases.