Covid-19 has shaken the world, with more than 2.5 million deaths and 115 million cases confirmed. BBC Panorama's Jane Corbin has scoured the globe to find the best examples of strategies for combating the virus. I have reported on Covid for the past year - now my mission was to find out from global leaders and senior health officials across four continents what their priorities were in tackling the virus. What has emerged strongly for me are four key areas which have been most effective in containing the spread of the virus and preventing deaths. Early and effective action to control borders and monitoring of arrivals Testing, tracking and tracing everyone suspected of being infected Welfare support for those in quarantine to contain the virus Effective leadership and consistent and timely public messaging No-one can claim to have got everything right. But the steps listed below highlight some policies from around the world that have proved effective. Piece them together and you have the blueprint for a "pandemic playbook" - a manual for managing future infectious disease outbreaks. STEP ONE: Preparation Stanley Park lives in Seoul, South Korea. When he went to pick up his daughter, Joo Yeon, from the airport, he greeted her not with a hug but with a mask and a bottle of sanitising spray. For Stanley, this isn't his first experience of a pandemic. He remembers the devastation and fear that the Mers outbreak brought to east Asia in 2015. It's an experience his country has learned from, with the government making 48 reforms to bolster public-health emergency preparedness and response. These have paid off. When coronavirus hit, officials were able to flatten the epidemic curve quickly, without closing businesses or implementing stricter stay-at-home restrictions nationally. After her arrival from Atlanta, Joo Yeon completed a strict two-week quarantine at her parents' house, downloaded an app that tracks her movements and received six check-up calls from the authorities. She took her quarantine so seriously that she "didn't even go to the garden, just in case". "From the very start we put in place thorough prevention measures to stop the same thing happening again - history repeating itself," Prime Minister Chung Sye-kyun said. STEP TWO: Test, track and trace "It's very challenging at the moment, I have no idea if the patients I see have coronavirus or not," David Hodges, a GP from north-east England, told Panorama in March 2020. "We might have hundreds of cases we're missing." As cases soared ahead of the first lockdown in late March, and with resources stretched, the UK government, which had been conducting contact tracing until this point, stopped testing in the community. It had the capacity to test only in hospitals. The government's formal test-and-trace programme was launched in May. Most countries in east Asia started contact tracing in January. In South Korea, hospitals like Yangji, in the Gwan-Ak district of Seoul, were designated to handle Covid from testing to treatment. Here, people don't even need to enter the building - they're tested at arm's-length in a special fully-sealed booth. The hospital processes all its own tests on site and the results are usually available within four or five hours. In the UK it can take a day or more.   Down the road from the hospital, a track-and-trace team follows up on every suspected case. The team can be forensic with the detail and has access to credit card and mobile phone data. It monitors CCTV throughout the district, sending teams out into the community to scour the streets when it sees something that concerns it. Prime Minister Chung Sye-kyun took personal charge of the situation before the country even had a confirmed case of Covid, giving priority to the three Ts - test, track and trace. "By applying that strategy we've achieved a good, meaningful result," Mr Sye-kyun has said. The death toll in South Korea, a country of 52 million people, stands at 1,693. The UK government says the testing system has continued to evolve and it is doing everything it can to improve it. STEP THREE: Quarantine support "Making people stay at home is the main reason we've been able to contain Covid," says Usha Kumari, a community health worker in Kerala, India. Usha is one of 30,000 accredited social-health activists, known as Asha workers. Usha's role has been to ensure everyone who needs to self-isolate in her patch does so. She gets their shopping, collects their medicine and anything they might need, so that they don't leave their homes. The support for those isolating doesn't end there. Community kitchens have been supplying up to 600 free meals to people self-isolating at home or in hospital each day and mental-health services have been offered since the start of the pandemic. Financial aid has been provided and, in some cases, bills were temporarily frozen. In the UK it wasn't until September that a payment of £500 was offered to those self-isolating. However, in the first four months of the UK scheme, two-thirds of applicants were rejected. According to a Scientific Advice Group for Emergencies report released in September, less than 20% of people in the UK who were required to self-isolate, fully quarantined. Now, the UK government's expanding eligibility for the support payment. It says four million people could qualify. Kerala's health minister KK Shailaja learned important lessons three years ago dealing with the deadly Nipah virus and has applied those lessons to tackling Covid. She insists that by ensuring support for those self-isolating, officials were able to control the spread and keep its hospitals from being overwhelmed. With a population of 35 million, Kerala went from having the highest number of cases in India in March 2020 to having among the lowest Covid-19 death rates in the world.