The discovery of another Covid-19 variant as the world nears the start of year three of the pandemic has a Groundhog Day ring to it.
In some ways, the pandemic cycles keep repeating: another threat emerges and travel bans return; a part of the world goes through case surges and reintroduced health measures; and here in New Zealand we suddenly feel grateful again for border quarantine.
But it is clear that much has changed and progress has been made in two years, even if key problems remain.
The fast identification of the Omicron variant and countries' swift reactions show that the lesson of not waiting to act until it's overwhelmingly too late has been widely learned. South Africa gave the world a heads up on the variant and there's experience built up over two years to tap into.
This differs from how slowly Covid-19 was originally dealt with and also the subsequent Alpha and Delta variants.
Governments, health authorities and scientists on the lookout for new variants rapidly responded to the Omicron news. The process has been so quick that there's an information gap on the variant. There are a number of questions about Omicron still to be answered. However, on Tuesday the World Health Organisation issued a warning that "the overall global risk is assessed as very high."
Director general of health Dr Ashley Bloomfield said New Zealand's approach was to "keep the virus out for as long as possible to learn more".
Travel bans can only slow spread - more than 20 countries have discovered cases of this variant and it was in Europe before South Africa raised the alarm - but awareness of Omicron has quickly been passed around and that gives people the chance to protect themselves better.
Mask-wearing, hand hygiene, social-distancing, working from home where possible, reducing mobility and doing things outdoors rather than indoors are immediate and effective protective measures against any of the variants.
We know this. Unfortunately in New Zealand there still appears to be a high level of resistance to masks, except when people are required to use them in shops.
Increasing vaccination levels, accelerating booster programmes, getting children aged 5 to 11 inoculated, and making use of the new antiviral pills, have now become even more urgent tasks for developed countries, including New Zealand.
Plugging vaccine gaps and emphasising booster shots are things the New Zealand response can get on with. Covid Response Minister Chris Hipkins said the rollout for kids, pending approval, should begin in January.
From mid January visitors to the European Union will need either a booster dose or be within nine months of their second shot. US medical professor and scientist Eric Topol tweeted that boosters "would help vs Omicron. Boosters induce a striking increase in level and breadth of neutralising antibodies."
The twin problems are getting more vaccines to world regions with low levels of doses, and also encouraging unvaccinated people in many other countries to get jabs.
Africa is easily the least vaccinated region in the world with less than 7 per cent of its population vaccinated.
In South Africa only 24.5 per cent of the population is fully vaccinated, according to Johns Hopkins University, and now the country is taking an economic hit from the travel ban.
In a world where people can move quickly from country to country and within them, variants emerging from low vaccinated areas can hitch a ride via that mobility.