Dear Reader:

* A disclaimer: I am not a doctor or a scientist, just a member (with a limited formal education in biology) studying the disease using online resources.

A vaccine specific to Covid-19 is being worked on (the longest term process, not expected before 2021). A non-specific vaccine is being worked on (an improved version of the old BCG vaccine for tuberculosis,VPM1002, see yesterday posts, a shorter term process, expected as early as summer 2020).

There is something else that’s being worked on, an ever shorter term process, expected to be available perhaps in a few weeks (?) It’s a non-vaccine method of passive immunization, and passive antibody therapy (also known as “convalescent plasma therapy), is the transferring of purified and concentrated antibodies produced by the  immune systems of those who have recovered from Covid-19 to people who are at risk of being infected (to prevent infection), and for people already infected with Covid-19 (to treat infection).

Passive immunization happens naturally as antibodies from the body of a pregnant woman transfer to her baby, and it can happen artificially via blood transfusions.

How antibodies work: the surface of viruses contain viral proteins that bind to host (human) cell receptors, making it possible for the virus to enter the human cell and infect it. Antibodies bind and block those surface viral proteins, and so, the virus is not able to enter and infect the human cell. This binding of the antibody to the virus is called neutralization, and it renders the virus no longer infectious.

There are other two ways that the antibodies render the virus impotent: “antibody-dependent cellular cytotoxicity”, and “antibody- dependent cellular phagocytosis”,  in which the antibodies stimulate the person’s specialized immune cells to attack and disintegrate the virus, or to “eat” the virus, respectively.

Passive antibody treatment is more effective when used for prevention of a disease than it is for treatment. To be used for treatment of a person already infected, it is most effective when administered shortly after the onset of symptoms, therefore, doctors will have to provide the treatment at the right time.

The above information is taken from Wikipedia and www. medicalnewstoday. com/ articles/ can-an-old-method-help-doctors-fight-covid-19.

According to a third source: markets. businessinsider. com/ news/ stocks/ Italian-biotech-leader-hopes-to-be-ready-with-plasma-based-treatment-for-covid-19-by-late-summer-of-2020 (April 7, 2020), a leading Italian biotech  (Kedrion, the world’s fifth biggest plasma company) announced two days ago that it started to develop a passive antibody therapy for treating the Covid-19 virus that can make it available to  patients in 3-6 months (July-Oct, 2020).

The idea is “to collect plasma from convalescent patients in the next 30 days.. in close collaboration with hospitals from some of the most hard- hit regions of Italy… to use plasma from about 100 patients who have recovered from Covid-19 in order to develop a dosage that can be injected through either intravenous or intramuscular means.. to either patients who are suffering fromCovid-19 or to health care workers to provide temporary passive immunization… the Italian prototype is a plasma derivative which could be especially effective in treating patients in critical condition”.

anita