A nurse tests a respirator called OxyGEN, which is to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

An employee works on the production of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

An employee works on the production line of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

Employees work on the production of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

An employee works on the production line of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

Employees work on the production line of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

An employee works on the production line of a new medical device called OxyGEN, a respirator to be sent to hospitals, during the coronavirus disease (COVID-19) outbreak, at the SEAT car factory of Martorell, near Barcelona, Spain April 7, 2020. REUTERS/Nacho Doce 

Teachers work in a lab at the SENAI (Brazil's National Industrial Learning Service) that interrupted the classes and started to fix and and train other professionals to repair damaged respirators, amid the coronavirus disease (COVID-19) outbreak, in Sao Paulo, Brazil, April 6, 2020. REUTERS/Rahel Patrasso 

A teacher from the SENAI (Brazil's National Industrial Learning Service) takes of his protection glasses after disinfect a damaged respirator to be fixed, amid the coronavirus disease (COVID-19) outbreak, in Sao Paulo, Brazil, April 6, 2020. REUTERS/Rahel Patrasso 

A teacher from the SENAI (Brazil's National Industrial Learning Service) fixes a damaged respirator, amid the coronavirus disease (COVID-19) outbreak, in Sao Paulo, Brazil, April 6, 2020. REUTERS/Rahel Patrasso 

A teacher from the SENAI (Brazil's National Industrial Learning Service) fixes a damaged respirator, amid the coronavirus disease (COVID-19) outbreak, in Sao Paulo, Brazil, April 6, 2020. REUTERS/Rahel Patrasso 

A teacher from the SENAI (Brazil's National Industrial Learning Service) pushes damaged respirator to fixe, amid the coronavirus disease (COVID-19) outbreak, in Sao Paulo, Brazil, April 6, 2020. REUTERS/Rahel Patrasso 

A combination of four images shows a surgical mask (top R), a self-made protective mask (top L), a FFP3 Respirator mask (bottom L) and a FFP2 Respirator mask (bottom R) in these illustrations taken, April 6, 2020. REUTERS/Kai Pfaffenbach/Illustration 

A FFP3 Respirator mask is seen in this illustration taken, April 6, 2020. REUTERS/Kai Pfaffenbach/Illustration 

A FFP2 Respirator mask is seen in this illustration taken, April 6, 2020. REUTERS/Kai Pfaffenbach/Illustration 

A FFP2 Respirator mask is seen as the spread of the coronavirus disease (COVID-19) continues in Hanau, Germany, April 6, 2020. REUTERS/Kai Pfaffenbach 

A FFP3 Respirator mask is seen in this illustration taken, April 6, 2020. REUTERS/Kai Pfaffenbach/Illustration 

Wokers install a system made by Battelle which can sterilize 80,000 N95 respirator masks per day to be reused by health care workers amid the coronavirus disease (COVID-19) outbreak in Somerville, Massachusetts, U.S., April 5, 2020. REUTERS/Brian Snyder 

Wokers install a system made by Battelle which can sterilize 80,000 N95 respirator masks per day to be reused by health care workers amid the coronavirus disease (COVID-19) outbreak in Somerville, Massachusetts, U.S., April 5, 2020. REUTERS/Brian Snyder 

Wokers install a system made by Battelle which can sterilize 80,000 N95 respirator masks per day to be reused by health care workers amid the coronavirus disease (COVID-19) outbreak in Somerville, Massachusetts, U.S., April 5, 2020. REUTERS/Brian Snyder 

A 3M model 8210 N95 particulate respirator mask is seen hanging on a rear view mirror of a car as the spread of coronavirus disease (COVID-19) continues, in New Orleans, Louisiana U.S., April 4, 2020. REUTERS/Carlos Barria 

A man has his respirator mask adjusted outside Guasmo Sur General Hospital after Ecuador reported new cases of coronavirus disease (COVID-19), in Guayaquil, Ecuador April 1, 2020. REUTERS/Vicente Gaibor del Pino 

Nico Hofeditz explains a prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

Peter Mross explains a prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

Peter Mross explains a prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

A prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university is seen, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

A prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university is seen, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

A prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university is seen, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

A prototype of a respirator for use on partially recovered coronavirus patients, developed by scientists of Germany's Marburg university is seen, as the spread of the coronavirus disease (COVID-19) continues, in Marburg, Germany, March 31, 2020. REUTERS/Ralph Orlowski 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A nurse wears a full-face snorkelling mask, as part of a donation of 50 snorkeling masks by sports chain Decathlon, transformed as respirators to help treat coronavirus disease (COVID-19) patients at the Erasme (Erasmus) Hospital in Brussels, Belgium March 30, 2020. REUTERS/Yves Herman 

A hospital bed and respirator at ExCel London, seen inside during its conversion into the temporary NHS Nightingale Hospital, comprising of two wards, each of 2,000 people, to help tackle the coronavirus outbreak, in Newham, London, Britain March 30, 2020. Stefan Rousseau/Pool via REUTERS 

A hospital bed and respirator at ExCel London, seen inside during its conversion into the temporary NHS Nightingale Hospital, comprising of two wards, each of 2,000 people, to help tackle the coronavirus outbreak, in Newham, London, Britain March 30, 2020. Stefan Rousseau/Pool via REUTERS 

A hospital bed and respirator at ExCel London, seen inside during its conversion into the temporary NHS Nightingale Hospital, comprising of two wards, each of 2,000 people, to help tackle the coronavirus outbreak, in Newham, London, Britain March 30, 2020. Stefan Rousseau/Pool via REUTERS 

A hospital bed and respirator at the ExCel London, seen inside during its conversion into the temporary NHS Nightingale Hospital, comprising of two wards, each of 2,000 people, to help tackle the coronavirus outbreak, in Newham, London, Britain March 30, 2020. Stefan Rousseau/Pool via REUTERS 

An employee works on an electronic device of a respirator system as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

An employee works on an electronic device of a respirator system as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

An employee works on a respirator system as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

Employees works on a respirator system as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

Employees works on electronic devices of a respirator system as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

Respirator systems are seen reflected over the screen of a respirator as the spread of the coronavirus disease (COVID-19) continues, in Buenos Aires, Argentina March 27, 2020. REUTERS/Agustin Marcarian 

Director for the intensive care unit at the University Medical Center Hamburg-Eppendorf Stefan Kluge shows the function of a respirator to the media in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

A respirator system is pictured at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

A respirator system is for training reasons attached to a dummy at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

A respirator system is for training reasons attached to a dummy at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Doctors receive instructions for a respirator system at the intensive care unit of the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Director for the intensive care unit at the University Medical Center Hamburg-Eppendorf Stefan Kluge shows the function of a respirator in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Director for the intensive care unit at the University Medical Center Hamburg-Eppendorf Stefan Kluge shows the function of a respirator in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

Director for the intensive care unit at the University Medical Center Hamburg-Eppendorf Stefan Kluge shows the function of a respirator in Hamburg, Germany, March 25, 2020, as the spread of the coronavirus disease (COVID-19) continues. Axel Heimken/Pool via REUTERS 

A nurse wears a powered air purifying respirator (PAPR) for coronavirus disease (COVID-19) protection in a Maryland hospital, March 18, 2020. Picture taken March 18, 2020. REUTERS/Rosem Morton 

Anne-Sophie Devos, teacher in nursering brings artificial respiration devices and protective suits at the Saint-Jean hospital while Belgian government imposed a coronavirus lockdown in an attempt to slow down the coronavirus disease (COVID-19), in Brussels, Belgium March 20, 2020. REUTERS/Yves Herman