A new kind of brain teaser

Adnan, Benjamin and Sameer ( let's call them A,B, and C for short) want to decide which covid vaccine to take. You need to help them to decide.

A has already had covid, and has now tested negative. B has not had covid and has now tested negative. C has not taken a test but has taken the first dose of Covaxin.

They all want to study abroad, in Europe.  A is going to country A which has approved Covishield but not Covaxin, B to Country B which has approved no Indian vaccine, and C to Country C which, according to sources in the Indian Foreign Office, is very likely to approve both, very soon, since they are under threat of all their citizens who are currently in India being sent to Tihar Jail for fourteen days compulsory quarantine, under foreign minister Jaishankar's arm-twisting exercise  India Intimidating Initiative (III for short).

Meanwhile Diksha ( let's call her D) who is A's cousin and  studying medicine at CDEF ( College of Doctors Evengelizing Fear ) and is a member of VV,  Vaccine Vigilantes, has some statistics on vaccines. Covishield is 75 percent effective after 1 dose, 90 percent effective  after 2 doses. Covaxin is 70 and 83 respectively. Taking covishield after taking covaxin , two doses of both, is 97 percent effective, but given shortage of vaccines right now, one may have to wait for six months before that is allowed. Taking annual booster shots of all of them is next on the cards, as per information she has collected from reliable sources. But, Country A has only Pfizer vaccine available, Country B has Pfizer and Moderna, and Country C has only the Chinese vaccine. The students may have to come to India to take their booster shots actually, if they want Covaxin or Covishield.

Meanwhile Pfizer has been given approval for manufacturing  in India, and will take six months to hit the shelves. A is all in favor of Pfizer, B is confused, and C will never touch it since it uses the new unproven mRNA technology which he fears may play havoc with the DNA in his cells.

All three of them have the option of deferring their admissions by one year. 

Meanwhile, the respective colleges where A , B and C are studying have mandated vaccines, whichever available version is fine, or else they cannot go to campus. Not going to campus will result in their project being declared invalid by the foreign universities, so it is essential for them to go to campus to retain their admission.

A is gung ho about the vaccine since all the people in his family have taken it and no one has died, B is sceptical since his uncle who was hale and hearty till then, died of cardiac arrest  exactly three days after taking the vaccine, and C is afraid of injections.

So, you need to decide for A, B, and C, keeping all factors in mind:

1. Should they take admission this year or defer to next year?

2. What should their vaccine strategy be - which vaccine/s , what frequency, and strategy for booster shots

Please send in your answers by evening today.