A medical practitioner takes a blood sample for the COVID 19 IgG and IgM Rapid Test, designed to detect the coronavirus antibodies, from a patient in Richmond, Texas, U.S., April 25, 2020. REUTERS/Adrees Latif 

A medical practitioner uses a blood sample from a patient for a COVID 19 IgG and IgM Rapid Test, designed to detect the coronavirus antibodies, in Richmond, Texas, U.S., April 25, 2020. REUTERS/Adrees Latif 

A patient undergoes dialysis treatment at a dialysis centre, amidst the coronavirus disease (COVID-19) outbreak, in Guayaquil, Ecuador April 18, 2020. Picture taken April 18, 2020. REUTERS/Santiago Arcos 

A health worker holds a blood sample while testing municipal workers from the Miraflores district of Lima for the coronavirus disease (COVID-19), in Lima, Peru April 13, 2020. REUTERS/Sebastian Castaneda 

A health worker is seen with blood samples during a testing of municipal workers from the Miraflores district of Lima for the coronavirus disease (COVID-19), in Lima, Peru April 13, 2020. REUTERS/Sebastian Castaneda 

Fake blood is seen in test tubes labelled with the coronavirus (COVID-19) in this illustration taken March 17, 2020. REUTERS/Dado Ruvic/Illustration 

Fake blood is seen in test tubes labelled with the coronavirus (COVID-19) in this illustration taken March 17, 2020. REUTERS/Dado Ruvic/Illustration 

Fake blood is seen in test tubes labelled with the coronavirus (COVID-19) in this illustration taken March 17, 2020. REUTERS/Dado Ruvic/Illustration 

Fake blood is seen in test tubes labelled with the coronavirus (COVID-19) in this illustration taken March 17, 2020. REUTERS/Dado Ruvic/Illustration 

A fish hook used by fish buyers is pictured at the Ofunato fish market in Ofunato, Japan September 24, 2019. REUTERS/Edgar Su 

Meat products are pictured in an EDEKA supermarket in Berlin, Germany, August 9, 2019. REUTERS/Fabrizio Bensch 

Meat products are pictured in an EDEKA supermarket in Berlin, Germany, August 9, 2019. REUTERS/Fabrizio Bensch 

Meat products are pictured in an EDEKA supermarket in Berlin, Germany, August 9, 2019. REUTERS/Fabrizio Bensch 

Meat products are pictured in an EDEKA supermarket in Berlin, Germany, August 9, 2019. REUTERS/Fabrizio Bensch 

Blood is seen on a spear used by a "picador" (mounted bullfighter) during a bullfight at the San Fermin festival in Pamplona, Spain, July 10, 2019. REUTERS/Susana Vera 

A deer is seen as the breeders cut off his antlers, famous for their strong healing effect, at "Alatau Maraly" farm in Kasymbek gorge, Almaty region, Kazakhstan June 1, 2019. Maral stags at this private farm undergo an annual cutting off their antlers to be sold to pharmaceutical companies. Picture taken June 1, 2019. REUTERS/Pavel Mikheyev 

A detail shows what is believed to be Leonardo Da Vinci's thumbprint (L) on his drawing of The Cardiovascular System and Principal Organs of a Woman, at A Life in Drawing, the largest exhibition of Leonardo's work in more than 65 years, at The Queen's Gallery, Buckingham Palace in London, Britain, May 23, 2019. REUTERS/Dylan Martinez 

A Turkana tribesman slaughters a bull during a wedding ceremony near Todonyang, Kenya March 22, 2019. Picture taken on March 22, 2019. REUTERS/Goran Tomasevic 

A Filipino penitent kneels before a crucifix after performing self-flagellation in Mabalacat City, Pampanga province, Philippines, April 18, 2019. REUTERS/Eloisa Lopez 

A medical worker draws blood from a woman for an HIV test during an event to raise awareness on World AIDS Day, in Kunming, Yunnan province, China December 1, 2018. REUTERS/Wong Campion 

Athens' Polytechnic school students carry a blood-stained Greek flag during a rally marking the 45th anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2018. REUTERS/Costas Baltas TPX IMAGES OF THE DAY 

A participant in costume and make-up poses for a photo during a Halloween parade at Walibi park in Wavre, Belgium, October 31, 2018. REUTERS/Yves Herman 

Nepalese army personnel drag a water buffalo during the sacrificial ceremony to mark "Dashain", the biggest religious festival for Hindus in Kathmandu, Nepal October 18, 2018. REUTERS/Navesh Chitrakar 

Belarusian hunters cut a killed elk as they take part in the hunting of wild ungulates near the village of Myshanka, Belarus October 6, 2018. Picture taken October 6, 2018. REUTERS/Vasily Fedosenko TPX IMAGES OF THE DAY 

Heads of fresh tuna fish lie on a table at the Tsukiji market in Tokyo, Japan, September 27, 2018. REUTERS/Issei Kato 

A three-dimensional printout of a human heart is seen at the Heidelberg University Hospital (Universitaetsklinikum Heidelberg) in Heidelberg, Germany, August 14, 2018. Picture taken August 14, 2018. To match Insight HEALTHCARE-MEDICAL TECHNOLOGY/AI REUTERS/Ralph Orlowski 

A man washes his knife as another uses a sack bag cover upon a goat after it was slaughtered for sacrifice, to celebrate the Muslim holiday Eid al-Adha, at a courtyard of a mosque in Kunming, Yunnan province, China August 22, 2018. REUTERS/Wong Campion 

A cow's feet, adorned with bangles, seen after its sacrificial slaughter in celebration of Eid al-Adha, in Karachi, Pakistan August 22, 2018. REUTERS/Akhtar Soomro 

A member of a shooting party holds a grouse on Forneth Moor on the opening day of the grouse shooting season, Scotland, Britain Aug 13, 2018. REUTERS/Russell Cheyne 

A man cuts dog meat at a dog meat restaurant ahead of local dog meat festival in Yulin, Guangxi Autonomous Region, China June 20, 2018. REUTERS/Tyrone Siu 

Pouches with platelets are seen as a volunteer donates blood during the international blood donation day in Nice, France, June 14, 2018. REUTERS/Eric Gaillard 

A paramedic takes a blood sample for DNA testing from a resident looking for a relative missing during the eruption of Fuego volcano, at the morgue in Escuintla, Guatemala June 7, 2018. REUTERS/Luis Echeverria 

A paramedic takes a blood sample for DNA testing from a resident looking for a relative missing during the eruption of Fuego volcano at the morgue in Escuintla, Guatemala, June 7, 2018. REUTERS/Luis Echeverria 

Members of the LGBT community take part in a protest to demand justice after a transgender Honduran woman, who was part of the caravan of Central American migrants that arrived at the U.S. border earlier this month, died in detention on Friday, outside the U.S. Embassy in Mexico City, Mexico June 6, 2018. REUTERS/Ginnette Riquelme 

Marked railroad ties are pictured close to the scene where they found a body near Wiesbaden-Erbenheim, Germany, June 6, 2018. REUTERS/Thorsten Wagner 

Worshippers with stains of goat's blood on their clothes participate in a ceremony during the celebrations of the voodoo rituals in Souvenance, Haiti, April 1, 2018. REUTERS/Andres Martinez Casares 

A worshipper re-enacts Christ's journey along the Via Dolorosa during a Good Friday procession in Jerusalem's Old City, March 30, 2018. REUTERS/Ammar Awad 

A rope with blood on it is pictured while a masked penitent flagellates himself during a procession as part of Holy Week celebrations in Taxco in the Mexican state of Guerrero, March 29, 2018. Picture taken March 29, 2018. REUTERS/Edgard Garrido 

Hooded penitents pray after self-flagellation during Maundy Thursday Lenten rites in Mandaluyong city, metro Manila, Philippines March 29, 2018. REUTERS/Romeo Ranoco 

A voter's finger is marked with ink at a polling station during the second day of the presidential election in Alexandria, Egypt March 27, 2018. REUTERS/Mohamed Abd El Ghany 

A voter's finger is marked with ink at a polling station during the second day of the presidential election in Alexandria, Egypt March 27, 2018. REUTERS/Mohamed Abd El Ghany 

An Egyptian woman has her finger stained with ink after casting her vote during the first day of the presidential election at a polling station in Cairo, Egypt, March 26, 2018. REUTERS/Amr Abdallah Dalsh 

A Kenya Wildlife Service (KWS) veterinary takes blood samples of a tranquillised elephant during a translocation exercise to Ithumba Camp in Tsavo East National Park, in Solio Ranch in Nyeri County, Kenya February 21, 2018. REUTERS/Thomas Mukoya 

A medic arranges blood samples donated during a Valentine's Day campaign, which theme is "Show your love, donate blood", in Nairobi, Kenya February 14, 2018. REUTERS/Thomas Mukoya 

Animal rights activists perform, demanding the abolition of bullfights, during a demonstration in Medellin, Colombia February 11, 2018. REUTERS/Fredy Builes 

A dead Llama is seen during a ceremony to bless the mine by offering animal sacrifice as part of Andean carnival celebrations, outside the Mina Itos on the outskirts of Oruro, Bolivia February 9, 2018. REUTERS/David Mercado 

A vendor holds a quail to slaughter for customers at Ka Faroshi bird market in Kabul, Afghanistan, January 18, 2018. REUTERS/Mohammad Ismail SEARCH "BIRD MARKET" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Legs of an Animal rights activist are covered with fake blood during a protest against the use of leather and fur in Barcelona, Spain, January 20, 2018. REUTERS/Albert Gea 

ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF INJURY OR DEATH A shoe is seen near blood stains following a car bomb attack in Hasaka province, Syria, October 13, 2017. REUTERS/Rodi Said TPX IMAGES OF THE DAY 

A penitent takes part in a religious procession in Guardia Sanframondi, south Italy, August 27, 2017. REUTERS/Ciro De Luca 

A view of a maternity hospital damaged from the war against Islamic State militants in east Mosul, Iraq August 15, 2017. Picture taken August 15, 2017. REUTERS/Azad Lashkari TPX IMAGES OF THE DAY 

A butcher prepares a piece of meat at the Boucherie St Francois butcher shop in the old city of Nice, France July 28, 2017. REUTERS/Eric Gaillard 

ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF INJURY OR DEATH People look at a pool of blood outside the office of the administrator of Kinshasa's Central Market in Kinshasa, Democratic Republic of Congo July 14, 2017. REUTERS/Aaron Ross TPX IMAGES OF THE DAY 

A Sumatran tiger licks a frozen blood lollipop on a hot summer day at the Bioparco zoo in Rome, Italy June 27, 2017. REUTERS/Tony Gentile TPX IMAGES OF THE DAY 

A protestor's hands are seen bound together as he is detained by police during May Day protests in Seattle, Washington, U.S. May 1, 2017. REUTERS/David Ryder 

The head of a sacrificed chicken is seen on an offering plate during the "Sindoor Jatra" vermillion powder festival at Thimi, in Bhaktapur, Nepal April 15, 2017. REUTERS/Navesh Chitrakar 

A farmer from the southern state of Tamil Nadu rubs blood on a fellow protestors feet after deliberately cutting himself with a razor blade during a protest demanding a drought-relief package from the federal government, in New Delhi, India April 7, 2017. REUTERS/Cathal McNaughton 

An injured person lies on the ground after an incident on Westminster Bridge in London, Britain Britain March 22, 2017. REUTERS/Toby Melville

A man receives treatment inside the dialysis center in the rebel-held town of Douma, in the besieged Eastern Ghouta suburbs of Damascus, Syria March 15, 2017. REUTERS/Bassam Khabieh 

Devotees walk on a blood-stained floor after a suicide blast on Thursday, at the tomb of Sufi saint Syed Usman Marwandi, also known as the Lal Shahbaz Qalandar shrine, in Sehwan Sharif, Pakistan's southern Sindh province, February 17, 2017. REUTERS/Akhtar Soomro