Question: Who played the main characters in Tomas Alfredson's 2008 vampire film?

Context paragraphs:
Lina Leandersson: Lina Leandersson (born 27 September 1995) is a Swedish actress.  She played the lead role of Eli in the 2008 Swedish romantic vampire film "Let the Right One In", based on the novel by the same name.  Born in Falun, Leandersson started performing at an early age.  She acted in local amateur theatre performances, and had a few brief television appearances in 2006.  At the age of eleven, Leandersson was cast to play one of the two leads in Tomas Alfredson's film, "Let the Right One In", after applying for the role through a web-based casting service.  The film was an international success, and Leandersson's performance as the vampire Eli brought her widespread critical acclaim as well as several awards and nominations.  She has stated that she wants to continue acting.

Tinker Tailor Soldier Spy (film): Tinker Tailor Soldier Spy is a 2011 Cold War espionage film directed by Tomas Alfredson.  The screenplay was written by Bridget O'Connor and Peter Straughan, based on John le Carré's 1974 novel of the same name.  The film, starring Gary Oldman as George Smiley, along with Colin Firth, Tom Hardy, John Hurt, Toby Jones, Mark Strong, Benedict Cumberbatch, and Ciarán Hinds, and featuring David Dencik, is set in London in the early 1970s and follows the hunt for a Soviet double agent at the top of the British secret service.

Screwed in Tallinn: Screwed in Tallinn (Swedish: Torsk på Tallinn ) is a 1999 Swedish comedy-drama film written by and starring the comedy group Killinggänget, and directed by their member Tomas Alfredson.  Made in a mockumentary style, it revolves around a group of Swedish single men who travel by bus to Estonia where they have been promised to meet Estonian women.

Four Shades of Brown: Four Shades of Brown (Swedish: Fyra nyanser av brunt ) is a 2004 Swedish film written by the comedy group Killinggänget and directed by their member Tomas Alfredson.  The film stars Robert Gustafsson, Johan Rheborg, Henrik Schyffert, Jonas Inde, Maria Kulle and Ulf Brunnberg.  The film consists four interweaved stories about life tragedies, with settlements related to fatherhood as the common theme.  It was produced by Sveriges Television.

Petra Nielsen: Petra Nielsen (born "Petra Magdalena Nielsen" 1 February 1965 in Stockholm) is a Swedish singer and actress.  She has starred on Broadway during her career.  Her mother is Swedish actress Monica Nielsen and her father Adam Inczédy-Gombos.  She is best known for her appearances at the Chinatheater in Stockholm in the 1990s, in musicals including "Grease" and "Fame".  She participated in Melodifestivalen in 2004, finishing fourth with "Tango!  Tango!" .  She received some international fame when she appeared in the vampire film Frostbite as one of the main characters, Annika.

The Snowman (2017 film): The Snowman is an upcoming 2017 British crime thriller film directed by Tomas Alfredson and written by Hossein Amini and Peter Straughan, based on the novel of the same name by Jo Nesbø.  The film stars Michael Fassbender, Rebecca Ferguson, Charlotte Gainsbourg, Val Kilmer and J. K. Simmons.  Principal photography began on 18 January 2016 in Norway.  The film will be released by Universal Pictures on 13 October 2017 and on 20 October 2017 in the United States.

Let the Right One In (film): Let the Right One In (Swedish: "Låt den rätte komma in" ) is a 2008 Swedish romantic horror film directed by Tomas Alfredson, based on the 2004 novel of the same title by John Ajvide Lindqvist, who also wrote the screenplay.  The film tells the story of a bullied 12-year-old boy who develops a friendship with a vampire child in Blackeberg, a suburb of Stockholm, in the early 1980s.  Alfredson, unconcerned with the horror and vampire conventions, decided to tone down many elements of the novel and focus primarily on the relationship between the two main characters.  Selecting the lead actors involved a year-long process with open castings held all over Sweden.  In the end, the 11-year-olds Kåre Hedebrant and Lina Leandersson were chosen for the leading roles.  They were subsequently commended by both Alfredson and film reviewers for their performances.

Tomas Alfredson: Hans Christian Tomas Alfredson (born 1 April 1965) is a Swedish film director who is best known internationally for directing the 2008 vampire film "Let the Right One In" and 2011 espionage film "Tinker Tailor Soldier Spy".  Alfredson has received the Guldbagge award for Best Direction twice; in 2005 for "Four Shades of Brown", and in 2008 for "Let the Right One In".

Bert (TV series): Bert is a Swedish television series with 12 episodes, based on the Bert Diaries by Anders Jacobsson and Sören Olsson, and originally airing over SVT each Saturday evening during the period of 1 October-17 December 1994.  It was directed by Tomas Alfredson and Svante Kettner.  The theme song was performed by Lill-Babs, and called "Älskade ängel".  Another song regaining revival with the TV series was Sven-Olof Sandberg's 1938 success "Är det så här när man är kär".

65th British Academy Film Awards: The 65th British Academy Film Awards, more commonly known as the BAFTAs, were held on 12 February 2012 at the Royal Opera House in London, honouring the best national and foreign films of 2011.  The nominations were announced on 17 January 2012 by actor Daniel Radcliffe and actress Holliday Grainger.  Presented by the British Academy of Film and Television Arts, accolades are handed out for the best feature-length film and documentaries of any nationality that were screened at British cinemas in 2011.  Stephen Fry, who hosted from 2001 to 2006, returned to host the ceremony. " The Artist" won seven awards out of its twelve nominations, including Best Film, Best Director for Michel Hazanavicius, and Best Actor for Jean Dujardin.  Meryl Streep won Best Actress for "The Iron Lady".  Christopher Plummer won Best Supporting Actor for "Beginners" and Octavia Spencer won Best Supporting Actress for "The Help". " Tinker Tailor Soldier Spy", directed by Tomas Alfredson, was voted Outstanding British Film of 2011.  Director Martin Scorsese was given the BAFTA Fellowship and Sir John Hurt garnered the BAFTA Outstanding British Contribution to Cinema Award.

Supporting paragraphs: Tomas Alfredson Let the Right One In (film)
Answer: Kåre Hedebrant and Lina Leandersson