Why India is facing oxygen shortage during 2nd Covid wave?
Over the past week, many breathless Covid-19 patients have died due to the unavailability of medical oxygen in hospitals across some states in the country. Contrary to claims, the shortage of oxygen in some states is not due to lower production or FY21 exports.
The second wave of the Wuhan virus infections in India commenced in mid-March 21. The Indian Prime Minister said that ‘it has shaken the country’. By third week of April 21 most newspaper headlines started flashing oxygen crisis. Patients were dying, people were in distress, judiciary was in anguish, and hospitals’ administrations were in helpless panic, some of the elected leaders made political statements. Here are some sample headlines.
‘City hospital gasps for oxygen on hour to hour basis’ ‘Horror story from sharing O2 cylinders to halting admissions’.‘Delhi NCR in Chokehold still, four die at Gurgaon Hospital’.‘Gurgaon and Rewari eight patients die due to shortage of oxygen. National Health Emergency: Supreme Court asks center for plan today; How will you bolster supply of .
What is a Covid-19 wave? How do we identify it?
There are a number of infectious diseases. Some of them take epidemic or pandemic proportions such as Covid-19 and swine flu. When their progress over time is graphed on paper, they form a wave pattern showing that the incidents of infection peaked at a certain time frame followed by a valley.
This crest-trough pattern of the spread of an epidemic or pandemic is called a ‘wave’. But not all infectious diseases follow this pattern — such as AIDS and tuberculosis. There are some other diseases that follow a seasonal wave pattern, such as the HKU1 coronavirus that causes common cold and peaks during winters.
Whole virus vaccines use a weakened (attenuated) or deactivated form of the pathogen that causes a disease to trigger protective immunity to it. There are two types of whole virus vaccines. Live attenuated vaccines use a weakened form of the virus, which can still grow and replicate, but does not cause illness. Inactivated vaccines contain viruses whose genetic material has been destroyed by heat, chemicals or radiation so they cannot infect cells and replicate, but can still trigger an immune response.
Both are tried and tested vaccination strategies, which form the basis of many existing vaccines – including those for yellow fever and measles (live attenuated vaccines), or seasonal influenza and hepatitis A (inactivated vaccines). Bacterial attenuated vaccines also exist, such as the BCG vaccine for tuberculosis.
Rather than injecting a whole pathogen to trigger an immune response, subunit vaccines (sometimes called acellular vaccines) contain purified pieces of it, which have been specially selected for their ability to stimulate immune cells. Because these fragments are incapable of causing disease, subunit vaccines are considered very safe. There are several types: protein subunit vaccines contain specific isolated proteins from viral or bacterial pathogens; polysaccharide vaccines contain chains of sugar molecules (polysaccharides) found in the cell walls of some bacteria; conjugate subunit vaccines bind a polysaccharide chain to a carrier protein to try and boost the immune response. Only protein subunit vaccines are being developed against the virus that causes COVID-19.
Other subunit vaccines are already in widespread use. Examples include the hepatitis B and acellular pertussis vaccines (protein subunit), the pneumococcal polysaccharide vaccine (polysaccharide), and the MenACWY vaccine, which contains polysaccharides from the surface of four types of the bacteria which causes meningococcal disease joined to diphtheria or tetanus toxoid (conjugate subunit).