♦What is Covid Vaccine? How it is prepared?
A vaccine is meant to develop immunity. In order to develop immunity human body should generate antibodies. Since antibodies have good 'immunity memory' immunity persists for long in the body and it can fight the virus once it enters the body. Normally, vaccines are developed using either dead or less powerful viruses.
However, new technologies have equipped man to deviate from the traditional method and now vaccines are developed using nucleic acid or genes in the Covid virus that can immunize the body. This method help prevent mutations of the virus and side effects.
How does the covid vaccine act in the body?.
In the body it acts as antigen similar to virus and inspire body to generate immunizing cells and antibodies.
Which are the vaccines that received immediate approval?
This is developed jointly by Pfizer pharmaceuticals in the US and Bayern Tech of Germany. The procedure applied is separating spike protein encoded RNA messenger from the nucleic acid of the virus which is then combined with lipid nano particle. Its efficacy is 90%. In order to maintain the potency this vaccine requires to be kept in freezer in -70 degree celsius. It is manufactured as a group of five multi dose vials.
The injection is administered mixing the vaccine with the saline provided with it. It has approval from the US,Europe and WHO.
It is developed by the pharmaceutical firm named Moderna situated in Massachusets in the US and a US government pharmaceutical firm named National Institute for Allergy and Infectious Disease. This also is mRNA vaccine. This vaccine does not contain preservatives and requires to be preserved in -20 degree centigrades. It is multi doses of 10 doses.
It is a joint venture product of Oxford University and a pharmaceutical company named Astra Zeneca.The procedure adopted to manufacture this vaccine is first seperating the spike protein on the surface of the virus which then is implanted adino viruses seen in chimpanzis. This adino virus poses no threat to humans. Its efficacy is 60% to 90%. Apart from this China has approved Sinopharma vaccine which has an efficacy of 79%.
A vaccine called Sputnik is used in Russia.
Types of vaccines developed in India.
Serum Institute of India is conducting the third phase trial of Oxford adino virus vaccine covishield developed by Serum institute. The methodology is vaccinating two doses on 1200 persons in 3.1 proportion with vaccine and placebo in a gap of 28 days and check the generation of antibodies after a gap of four weeks.
Temporary permission has been granted on 02, January. A trial going on in 25,800 volunteers across the country. The vaccine has been developed by Bharat Bio Tech in India and ICMR. The vaccine is administered in two doses.
Dr. Reddy's Laboratory
A trial is conducted on 1500 volunteers under Dr. Reddy's Laboratory. The vaccine used is the Adino vaccine Sputnik of Russia. In addition to the above, vaccines like Cadila D.N, A vaccine, Genova(MRNI vaccine),Biological E(recombinant),Serum Institute (Protein subunit vaccine) are undergoing trials at different stages in India.
Which are expected to be distributed?
Selection of a vaccine is a puzzle for any country. Three stakes that come are purchasing power,efficacy, production capacity, preservation and technology to run the vaccination drive. Both Moderna and Pfizer developed vaccines show good efficacy but costly. But it requires a chain of freezing equipment. Oxford and Sputnik vaccines are yet receive certification regarding their efficacy.The most desirable is one that shows good efficacy with less issues to handle.
When will these be ready.?
Normally it takes two years to ascertain the pros and cons of the vaccines. This trial is launched after the third phase. In a grave condition like this, full dose is given, observed for two months and the report is submitted to Drug Controller General who grants an emergency approval. This is not meant for the public; it is in trial mode. But Covishield and Covaccines are administered to health care workers from 16, January in India.
Cost of the vaccine.
Pfizer, Moderna will cost more than Rs.2000/- while Oxford/Serum Institute will cost more than Rs.500/-. It is better that the Government purchases, which can get it at Rs.200/-, and supply to the needy free of cost. If it is made available in the market the rich will purchase making the most needy lag. Two companies developed the vaccine utilizing the fund and facility of the Government. Other companies too can develop it now.
Who will be vaccinated first?
It depends on the resources of the government. The focus should be on criticality and death but not on eradicating pandemic. Then government has to be selective in finding the risk group. The first group should be doctors and nurses, then police, municipality employees. then people above sixty and then above fifty. Preference will be given in the above fifty group to those who suffer from hypertension and diabetes. So three crores in India will be vaccinated,subsequently herd immunity will be developed.
Precautions and after effects of vaccination.
Those who are allergic to food or medicine should inform the health care personnel. People can leave the premises only after thirty minutes of vaccination. After effects are supposed to be very rare, but since less is known about it long time monitoring will be held. Some will have pain on the site of injection, fever,and aches.
Make sure no one is panic once there is any after effect. Mask and physical distance should be followed even after vaccination. Time to develop immunity after vaccination. Partial immunity within 10-15 days after the first dose and full immunity after 14 days of second dose.
Is booster dose needed?
Two doses are to be administered. The immunity is expected to last for months. Hence booster dose is not required. Is vaccination required for the patients cured of disease.? As the Covid affected develop immunity they are not required to be vaccinated.
Will the disease transmit from the immunised?
The chance of transmission is less according to the studies. But detailed studies are still underway.
What about vaccinating children and aged?
The vaccines available have undergone trial in the aged population. Moreover, the aged group is the most preferred group. Patients suffering from diabetes, hypertension and heart diseases are among the preferred. But trials are not conducted on the persons under the age of 16; the immunity process is different among the children relative to the old. Children are not included in the preferred group.
Can pregnant women receive vaccine.?
No. Pregnant lady has undergone trial with the present vaccines. Moderna vaccine conducted trials on pregnant rats, but no side effect has been found.
What is the selection process for vaccinating people?
It is like election process using booths. The list is to be prepared using voters list. A maximum 100 people will be vaccinated locally.