Who can take Covishield Vaccine: Efficacy and Side Effects.

At the first phase, COVID-19 vaccine was provided to the priority group – Health Care and Front-line employees. The second phase vaccinations, which began on March 1, 2021 permitted for several Indians above age 60 and Indians between age 45 and 59 with comorbidities to be vaccinated.

By April 1st, 2021, People over age 45 years (born before 1st Jan, 1977) are entitled to get the COVID-19 vaccine. By May 1, 2021, all eligible citizens above the age of 18 years can find the COVID-19 vaccine.


Covishield vaccines are developed by the collaboration of Oxford University and AstraZeneca and have been manufactured by the Serum Institute of India (SII).

Type of VaccineRecombinant viral-vector vaccine
Dose                       0.5 ml each
Course                           2-doses
Schedule               12-16weeks apart
Vaccination during Pregnancy                Not recommended
Vaccination to Paediatric age group   Not recommended
Vaccination to >18 years of age             Recommended
Vaccination to Lactating mother             Recommended
Storage and transportation                +2 C to +80C at all levels
Official website for registration COWIN

Formulations in Covishiels vaccine:

  • L-Histidine
  • Polysorbate 80
  • L-Histidine hydrochloride monohydrate
  • Disodium edetate dihydrate (EDTA)
  • Sucrose
  • Sodium chloride
  • Ethanol
  • Magnesium chloride hexahydrate

Adverse event or Side effects:

Following unwanted effects or adverse reactions have been reported with COVISHIELD vaccine.

  • Very common (may affect people in ratio 1:10) – tenderness, injection site pain, or itching where the injection is given, generally feeling unwell, feeling tired (fatigue), chills or feeling feverish, headache, feeling sick (nausea), joint pain or muscle ache
  • Frequent (may affect people in ratio 1:10) – swelling or swelling where the injection is given, fever, being sick (vomiting) or diarrhea, pain in legs or arms, signs symptoms, for example high temperature sore throat, runny nose, cough and chills
  • Uncommon (may affect people in ratio 1:100) — sleepiness or feeling dizzy, stomach pain, enlarged lymph nodes, excessive sweating, itchy skin, rash or hives
  • Not understood (the frequency Cannot be determined by the available data) -acute allergic reaction (anaphylaxis), acute swelling of the lips, mouth and throat (that may Lead to difficulty in swallowing or breathing)
  • Rarest: Important blood clotting (venous and/or arterial thrombosis) in combination with reduced platelet count (thrombocytopenia) have been observed very rarely (using a frequency greater than 1 in 100,000 vaccinated people).


The contraindications to next dose of vaccine are:
  1. If you had a severe allergic reaction or anaphylaxix following a previous dose.
  2. If your treating physician considered this event as a severe allergic reaction to the vaccine, then you shouldn’t take second dose of medicine. If you experience any other adverse event (known or unknown) after initial dose, then you can take the next dose.
  3. Patients that have experienced major blood clotting (venous and/or arterial thrombosis) in conjunction with low platelet count (thrombocytopenia) following initial dose of vaccine.
  4. Covishield continues to be treated in people with or without comorbid states in clinical trials and the safety profile was comparable in those with or without comorbid illness (e.g.: Hypertension, Cardiovascular Disease, Asthma, Diabetes, etc.). People with clinically secure comorbid conditions can receive the vaccine. Kindly follow up with your treating physician for a risk benefit assessment according to clinical decision before taking the medicine.
Provisional / temporary contraindications:

In these circumstances, COVID-19 vaccination will be postponed for 3 months following recovery

Persons having active symptoms of SARS-CoV-2 infection.

SARS-COV-2 patients who have been granted anti-SARS-CoV-2 monoclonal antibodies or convalescent plasma

Acutely unwell and hospitalized (with or without consuming care) patients due to any illness.

Other Health issues:

Co-morbidities like Diabetes, Hypertension, Asthma, Cardiovascular disorder – can take vaccine without any hesitation. They don’t have to skip the medication. On the day of vaccination, use your normal dose and go for the vaccination.
Autoimmune diseases- Rheumatoid arthritis, Psoriasis, SLE, Sickle cell anemia etc.; Cancers; G6PD deficiency; Food and drug allergies; On immunosuppressants, on anti-platelet or anti coagulants medications- Under medical supervision, you can proceed with your vaccination.
How can a person know if he's a coagulation disorder? What tests can be run?

These persons should take the vaccine under the supervision of the treating physician. Patients that are admitted in hospital or ICU and also have bleeding problems should postpone the vaccination till they’re discharged. But, several people with heart and mind disorders are on blood thinners such as aspirin and antiplatelet drugs. They can continue with their medicines and possess the vaccines. For them, vaccines are absolutely safe.

The health advisory also states that those with immunity issues should be careful about taking the vaccine. What will be the markers of Immunity issues?

Immune issues are of two types: one, immunosuppression due to any illness such as AIDS, and people on immunosuppressant medications like anti-cancer medications, steroids, etc.. Second, immunodeficiency in people who suffers from some defect in the body’s protective system like congenital immunodeficiency.

Currently, available COVID-19 vaccines don’t have any live virus and therefore individuals with immune problems can have the embryo securely. However, the vaccine might not be as effective in them. One needs to inform the vaccinator concerning the medications they have and if they are experiencing any known immune troubles. The vaccinator should have a record of someone’s medical condition.

Pregnancy & Lactation:

Pregnant & Lactating women have not been part of any COVID-19 vaccine clinical trial up to now. Therefore, women who are pregnant or not certain of the pregnancy; and lactating women shouldn’t get COVID-19 vaccine at this time

There is a limited experience with the usage of this vaccine in pregnant women. Preliminary animal studies don’t indicate direct or indirect harmful effects with respect to pregnancy, embryofetal development, parturition or postnatal development; definitive animal research have not been completed yet. The complete relevance of animal studies to human risk with vaccines such as COVID-19 remains to be shown. Administration of COVISHIELDTM in pregnancy should only be contemplated when the potential benefits outweigh any potential risks for the mother and fetus.

Can Breastfeeding Women Receive Covishield?

It is not known, that Covishield is excreted in breast milk or not. However, the recent guidelines of the Indian Government have stated that Covishield vaccination is recommended for all lactating women. (According to letter issued by

WHO guidelines state that vaccine efficiency is expected to be similar in lactating women as in other adults. Since Covishield (ChAdOx1-S [recombinant]) vaccine is not a live virus vaccine, it is biologically and clinically unlikely to pose a threat to the breastfeeding child. On the basis of these considerations, a lactating woman who is part of a group advocated for vaccination according to the WHO Prioritization Road map, e.g., health workers, should be provided vaccination on an equal basis.

Who doesn't recommend discontinuing breastfeeding after vaccination?

It’s advised that breastfeeding mothers should consult their healthcare provider to get a risk benefit assessment based on clinical decision before taking the vaccine.

What is the impact of Covishield on fertility?

Preliminary animal studies don’t indicate direct or indirect harmful effects with respect to fertility.

Can women in their periods (menstruating) receive Covishield?

There is not any correlation between menstruation and the effect of the vaccine.

Moreover, this is a physiological phenomenon and it has nothing to do with resistance. Women in their periods can choose the vaccine.

In fact, there’s no prohibition to take any vaccine during menstruation.

Can I Take 1 Dose of Covishield and 1 Dose of Another Covid-19 Vaccine?

There’s not any safety, immunogenicity or efficacy information to support interchangeability of all Covishield with other COVID-19 vaccines. It is advisable that people who receive a first dose of Covishield complete the vaccination course with Covishield.

A person outside India, who's obtained first dose of AstraZeneca's vaccine, whether he can take instant dose of COVISHIELD at India?

Both Covishield (fabricated by Serum Institute of India Pvt Ltd) and COVID-19 Vaccine AstraZeneca (manufactured by AstraZeneca) are ChAdOx1 nCoV- 19 Corona Virus Vaccines (Recombinant). There is no data available when these two vaccines are used interchangeably.

However, the World Health Organization (WHO) states that ChAdOx1-S [recombinant] products (AstraZeneca AZD1222, SII Covishield) are considered equal and interchangeable for both doses and recommends that both doses should be administered with ChAdOx1-S product.

Efficacy of Covishield:

The following studies were done in UK, Brazil and USA for efficacy of Covishield after first dose and both the 2 doses.

StudiesEfficacy Percentage
UK and Brazil StudyOverall efficacy against symptomatic COVID-19 after more than 14 days after the 2nd dose66.7%
Vaccine efficacy against severe disease, hospitalization and death from 22 days after the first dose100%
3 weeks after single dose which was maintained till 3 months following single dose76%
Vaccine Efficacy in those who had an interval of ≥12 weeks between the 2 doses of covishield81.3%
Overall efficacy against symptomatic COVID-19 after more than 2 weeks after the 2nd dose76%
US StudyOverall efficacy against symptomatic COVID-19 after more than 2 weeks after the 2nd dose100%