(CNN) The world is in a "race against time" with the Omicron coronavirus variant, said European Commission President Ursula von der Leyen on Sunday, warning during a visit to Latvia that scientists and manufacturers will need weeks to fully understand the new variant.
As more cases are identified and governments around the world mobilize to respond to Omicron, an urgent meeting of G7 health ministers will be convened on Monday, the United Kingdom said. It also announced on Sunday new domestic public health rules requiring face coverings in shops and on public transport starting this week.
Omicron was first identified by scientists in South Africa, who raised alarm over its unusually high number of mutations on Thursday. Since then, at least a dozen other countries have confirmed cases of the new strain, with several other reporting suspected cases.
Apart from South Africa, the variant has been found in Botswana, Belgium, Canada, Australia, the Netherlands, Denmark, United Kingdom, Germany, Israel, Italy, the Czech Republic and Hong Kong.
On Sunday, Dutch authorities announced that at least 13 people had tested positive at Amsterdam Schipol airport after traveling from South Africa. The Netherlands' National Institute for Public Health and the Environment (RIVM) said in a statement that the variant had been detected through the sequencing of 61 positive Covid-19 samples that were obtained at the airport on Friday. It is "possible that the new variant will be found in more test samples," the institution noted.
Biostatistician professor Sheila Bird said the test results from Amsterdam were concerning, but that more data was needed. "There may be household clusters among the 13 Omicron positives or clustering may have been induced by where passengers were seated on the flight from South Africa," she told the Science Media Centre, adding that the vaccination status and age distribution of those infected will also need to be considered before any conclusions are made about the variant.
The situation should be seen with "alert rather than alarm until more is known," she said.
Canadian health officials also confirmed the country's first two Omicron cases in Ottawa on Sunday. Both individuals carrying the variant had recently traveled from Nigeria, according to a joint statement by Deputy Premier and Minister of Health Christine Elliott and Chief Medical Officer of Health Dr. Kieran Moore.
"We continue to urge the federal government to take the necessary steps to mandate point-of-arrival testing for all travelers irrespective of where they're coming from to further protect against the spread of this new variant," the joint statement also said.
The World Health Organization (WHO) has designated the Omicron variant, originally referred to as B.1.1.529, a "variant of concern."
WHO said on Friday that early evidence suggest the Omicron variant, first identified in South Africa, could pose an increased risk of reinfection and said that some of the mutations detected on the variant were concerning.
But WHO stressed that more research is needed to determine whether the variant is more contagious, whether it causes more severe disease, and whether it could evade vaccines.
"This variant has a large number of mutations and some of these mutations have some worrying characteristics," Maria Van Kerkhove, WHO's technical lead for Covid-19, said in a statement on Friday.
"Right now there are many studies that are underway ... so far there's little information but those studies are underway so we need researchers to have the time to carry those out and WHO will inform the public and our partners and our member states as soon as we have more information," she added.
The variant's discovery and fast spread across the world is an uncomfortable reminder that the pandemic is far from over.
A number of countries have slammed their borders shut to travelers from southern Africa, with the European Union, Japan, Australia, the United States, Canada, Rwanda and many others banning travelers from countries including South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi.
But South Africa and some of the other countries hit by the travel bans are pushing back. Speaking in Pretoria on Sunday, South African President Cyril Ramaphosa described the bans as baseless discrimination.
"These restrictions are unjustified and unfairly discriminate against our country and our Southern African sister countries. The prohibition of travel is not informed by science, nor will it be effective in preventing the spread of this variant. The only thing the prohibition on travel will do is to further damage the economies of the affected countries and undermine their ability to respond to, and recover from, the pandemic," he said.
South Africa's Ministry of International Relations and Cooperation has said the country was being punished for its transparency. "Excellent science should be applauded and not punished. The global community needs collaboration and partnerships in the management of the Covid-19 pandemic," the ministry said in a statement.
"A combination of South Africa's capacity to test and its ramped-up vaccination programme, backed up by world class scientific community, should give our global partners the comfort that we are doing as well as they are in managing the pandemic. South Africa follows and enforces globally recognized Covid-19 health protocols on travel. No infected individuals are permitted to leave the country," it added.
Malawi's President Lazarus Chakwera also criticized the travel bans, saying they were "uncalled for." "Covid measures must be based on science, not Afrophobia," he said on his official Facebook page.
Many experts said South African scientists deserved credit for their ability to quickly identify the risks stemming from the new variant.
The move to impose bans has also sparked criticism from WHO. "We've seen in the past, the minute there's any kind of mention of any kind of variation and everyone is closing borders and restricting travel. It's really important that we remain open, and stay focused," WHO's Head of Emergencies Dr. Michael Ryan said Saturday.
"South Africa has very, very good genomic sequencing capacity and capability ... certainly South Africa and any other countries should not be stigmatized for reporting it and doing the right thing," Michael Head, a senior research fellow in global health at the University of Southampton, told CNN in a phone interview.
However, Head said that travel bans, if used correctly, could play a role in controlling the outbreak.
"It's difficult scenario. It can buy you a bit of time. So if countries are imposing a ban and using that time, which will be at the moment a few weeks, to increase the pace of vaccination rollouts to make sure that any new antiviral drugs are available within the country, to increase testing, genomic surveillance at airports, that sort of thing, that's something you can usefully do with a travel ban," he said.
"If you just implement a travel ban and say 'right, job done' then that's no good to anyone. And if you do, as it were, punish countries for reporting new variants, we should really look to support them as well, whether it's infrastructure or funding or vaccine doses whatever might be appropriate."