![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/75YIRMKAZVS2DSC24IE35WS75M.jpg?smart=true&auth=007b71d3319cd9353820b92677afe62c584f6d916ec691eb51bb38fff3d3ebd0&width=400&height=225)
Braulia Amarilla, 75, being injected with a dose of the AstraZeneca vaccine in Asuncion, Paraguay. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LJLVUQY3WGJY6O34R36GS5267U.jpg?smart=true&auth=b9e572cfdbb95028253d56d380ed16104ab5d6edef67e37fd4dcf14eb9fad807&width=400&height=225)
A sign in Melbourne encouraging people to wear masks as the city's residents entered a seven-day lockdown to curb the spread of Covid-19. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/L6KTNX4UGVZEA364LY23DLUACM.jpg?smart=true&auth=9cf00cb62e12280f5b62bc4b10ef2ffba922355130a8e42e4218a4b1bfb711f2&width=400&height=225)
A resident outside the Pangsapuri Permai housing estate, which is under an enhanced movement control order because of a severe increase in the number of Covid-19 cases recorded over the past 10 days in Cheras, outside Kuala Lumpur, Malaysia. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/OU64WFBF63RCDM3S4JRRIL6JCA.jpg?smart=true&auth=abb71afdf9d64b0ad79d4001886722e50486882756950a8342fb8b63e994e9a1&width=400&height=225)
A mural in Denpasar, Bali, to spread awareness about the prevention of the coronavirus in Indonesia. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/EMMXRZBKWVGD7XI2P5ZV7NAWN4.jpg?smart=true&auth=f31fc1181425dfaed96b9b377b1378375012e8c4dee0b317060a60d63477710a&width=400&height=225)
A sign for contactless service outside a store during a lockdown in Melbourne, Australia. The city is ordering residents to stay home for the fourth time since the pandemic began as the return of infections tests the country's zero-tolerance approach to the virus. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/RISORGYQJGUHUT6TZRT4JEF5UI.jpg?smart=true&auth=ae9500e24ba7a6674ef1bdc9bbba3d1d141b69eab31e771ddb92e06942460332&width=400&height=225)
Kaironesa Suleman Allie, 76, receives a first dose of the Pfizer Covid-19 vaccine at a vaccination centre in Karl Bremer Hospital, in Cape Town, South Africa. South Africa is in a race against time to vaccinate as many people as possible with signs the virus may be surging again. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LIUZONC6TA6VWRDW62FVWD5LXA.jpg?smart=true&auth=573aaccc15e75249dc07d164b8ed41904263dbe9255006974bb29b7bfc50eb64&width=400&height=225)
Medical officers in personal protective equipment conduct a Covid-19 coronavirus test on a woman in southern Thailand's Yala province, amid an increase in active case numbers in the region. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/QUYNHKM7UCIESDWLQ4MBEVRG4U.jpg?smart=true&auth=82ae73067cb21e987f3254d151e9d91b43519ced46cec0a3bda8c9fd76411a37&width=400&height=225)
A pedestrian passes portraits of former Chinese leaders Zhou Enlai, left, Mao Zedong, centre, and Liu Shaoqi in Beijing, China. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LIIRGZ23IN2HX2ALSUC47KT3W4.jpg?smart=true&auth=7d3dcc32fc2091dc1f070def5f5e2fc8df12a704582977a1735c0c5a613567cf&width=400&height=225)
Covid-19 patient Celso da Silva Costa, 76, receives a visit from his wife Tania Lucia Mauricio at the Ronaldo Gazolla Hospital in Rio de Janeiro, Brazil. The Ronaldo Gazolla Hospital allows vaccinated family members to visit their loved ones, an indication that vaccination rates are beginning to climb in the state and a glimmer of hope for residents after more than a year of pandemic restrictions. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/W3QYXAY5WXRJM7FYW437APOQEE.jpg?smart=true&auth=edba1db28bbfba86def7cdc08d735a103a3d860f3a133b1995ec2bb9acf9ed2a&width=400&height=225)
A worker in Rio de Janeiro passes in front of a sign at a Fiocruz production facility that reads in Portuguese: "We produce the Covid-19 vaccine here." Brazil has administered 64 million Covid vaccine doses, with an average rate estimated at 659,189 doses per day. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/4KDL6GBZE774XN4GGK3DMVLVWQ.jpg?smart=true&auth=0fbb00cdc9bafce318bd6aea228ed4773f27c4004a7f0cee6d7ecc673a59f01d&width=400&height=225)
Administering a second dose of Astra Zeneca vaccine to a patient in a Covid-19 vaccination centre in Kigali, Rwanda. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/75YIRMKAZVS2DSC24IE35WS75M.jpg?smart=true&auth=007b71d3319cd9353820b92677afe62c584f6d916ec691eb51bb38fff3d3ebd0&width=400&height=225)
Braulia Amarilla, 75, being injected with a dose of the AstraZeneca vaccine in Asuncion, Paraguay. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LJLVUQY3WGJY6O34R36GS5267U.jpg?smart=true&auth=b9e572cfdbb95028253d56d380ed16104ab5d6edef67e37fd4dcf14eb9fad807&width=400&height=225)
A sign in Melbourne encouraging people to wear masks as the city's residents entered a seven-day lockdown to curb the spread of Covid-19. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/L6KTNX4UGVZEA364LY23DLUACM.jpg?smart=true&auth=9cf00cb62e12280f5b62bc4b10ef2ffba922355130a8e42e4218a4b1bfb711f2&width=400&height=225)
A resident outside the Pangsapuri Permai housing estate, which is under an enhanced movement control order because of a severe increase in the number of Covid-19 cases recorded over the past 10 days in Cheras, outside Kuala Lumpur, Malaysia. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/OU64WFBF63RCDM3S4JRRIL6JCA.jpg?smart=true&auth=abb71afdf9d64b0ad79d4001886722e50486882756950a8342fb8b63e994e9a1&width=400&height=225)
A mural in Denpasar, Bali, to spread awareness about the prevention of the coronavirus in Indonesia. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/EMMXRZBKWVGD7XI2P5ZV7NAWN4.jpg?smart=true&auth=f31fc1181425dfaed96b9b377b1378375012e8c4dee0b317060a60d63477710a&width=400&height=225)
A sign for contactless service outside a store during a lockdown in Melbourne, Australia. The city is ordering residents to stay home for the fourth time since the pandemic began as the return of infections tests the country's zero-tolerance approach to the virus. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/RISORGYQJGUHUT6TZRT4JEF5UI.jpg?smart=true&auth=ae9500e24ba7a6674ef1bdc9bbba3d1d141b69eab31e771ddb92e06942460332&width=400&height=225)
Kaironesa Suleman Allie, 76, receives a first dose of the Pfizer Covid-19 vaccine at a vaccination centre in Karl Bremer Hospital, in Cape Town, South Africa. South Africa is in a race against time to vaccinate as many people as possible with signs the virus may be surging again. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LIUZONC6TA6VWRDW62FVWD5LXA.jpg?smart=true&auth=573aaccc15e75249dc07d164b8ed41904263dbe9255006974bb29b7bfc50eb64&width=400&height=225)
Medical officers in personal protective equipment conduct a Covid-19 coronavirus test on a woman in southern Thailand's Yala province, amid an increase in active case numbers in the region. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/QUYNHKM7UCIESDWLQ4MBEVRG4U.jpg?smart=true&auth=82ae73067cb21e987f3254d151e9d91b43519ced46cec0a3bda8c9fd76411a37&width=400&height=225)
A pedestrian passes portraits of former Chinese leaders Zhou Enlai, left, Mao Zedong, centre, and Liu Shaoqi in Beijing, China. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/LIIRGZ23IN2HX2ALSUC47KT3W4.jpg?smart=true&auth=7d3dcc32fc2091dc1f070def5f5e2fc8df12a704582977a1735c0c5a613567cf&width=400&height=225)
Covid-19 patient Celso da Silva Costa, 76, receives a visit from his wife Tania Lucia Mauricio at the Ronaldo Gazolla Hospital in Rio de Janeiro, Brazil. The Ronaldo Gazolla Hospital allows vaccinated family members to visit their loved ones, an indication that vaccination rates are beginning to climb in the state and a glimmer of hope for residents after more than a year of pandemic restrictions. AP Photo
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/W3QYXAY5WXRJM7FYW437APOQEE.jpg?smart=true&auth=edba1db28bbfba86def7cdc08d735a103a3d860f3a133b1995ec2bb9acf9ed2a&width=400&height=225)
A worker in Rio de Janeiro passes in front of a sign at a Fiocruz production facility that reads in Portuguese: "We produce the Covid-19 vaccine here." Brazil has administered 64 million Covid vaccine doses, with an average rate estimated at 659,189 doses per day. Bloomberg
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/4KDL6GBZE774XN4GGK3DMVLVWQ.jpg?smart=true&auth=0fbb00cdc9bafce318bd6aea228ed4773f27c4004a7f0cee6d7ecc673a59f01d&width=400&height=225)
Administering a second dose of Astra Zeneca vaccine to a patient in a Covid-19 vaccination centre in Kigali, Rwanda. AFP
![](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/75YIRMKAZVS2DSC24IE35WS75M.jpg?smart=true&auth=007b71d3319cd9353820b92677afe62c584f6d916ec691eb51bb38fff3d3ebd0&width=400&height=225)
Braulia Amarilla, 75, being injected with a dose of the AstraZeneca vaccine in Asuncion, Paraguay. AP Photo
What are the Covid-19 variants and how do Alpha, Beta and Delta differ?
A new labelling system using the Greek alphabet was devised by the WHO
![Gillian Duncan](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/https%3A%2F%2Fs3.amazonaws.com%2Farc-authors%2Fthenational%2F736ebb26-e270-44c5-96a2-80452d783888.png?smart=true&auth=6b2c4dc0614f332daaa4e848c41f090496fd16da3ccccaa940132372e6a74710&width=70&height=70)
Gillian Duncan
09 June, 2021
- Listen In English
- Listen In Arabic