Connect with us

Coronavirus Explainers

COVID-19 Vaccine Explainer: How Do Vaccines Work?

Dr Kate O’ Brien of World Health Organisation (WHO) answers all questions about covid-19 vaccines

COVID-19 Vaccine Explainer: How Do Vaccines Work?

New Delhi: In India, the total number of people who have received coronavirus vaccine shots till Monday evening has crossed 60 lakh mark, according to the Union Health Ministry. India reached this milestone in 24 days, which according to the centre is the fastest in the world. The US took 26 days to reach this mark, whereas the UK achieved it in 46 days, the government underlined.

Till Monday evening, 60,35,660 beneficiaries were vaccinated through 1,24,744 sessions. Of these, 54,12,270 are healthcare workers and 6,23,390 frontline workers whose vaccination started on February 2, Additional Secretary in the Health Ministry Manohar Agnani said.

As COVID-19 vaccine drive gets bigger and bigger with each passing day, not just in India, but across the world, World Health Organisation (WHO) expert – Dr Kate O’ Brien, Director of the Department of Immunization, Vaccines and Biologicals decodes what happens next, after one has taken their COVID-19 jab and also busts the myths floating around vaccination.

Also Read: COVID-19 Explained: Will The COVID-19 Vaccine Be Effective Against The Latest Coronavirus Variant?

When Does The Immunity Kick In

WHO’s Dr Kate O’ Brien says,

The vaccines that we have right now are all two-dose vaccines. After the first dose, we see a good immune response that kicks in within about two weeks of that first dose. And it’s really the second dose that then further boosts that immune response and we see immunity gets even stronger. The booster shot takes shorter period of time to kick in the immunity.

Also Read: Coronavirus Vaccine Glossary: 15 Terms To Know About Vaccination

How Long Does The Immunity Last?

Dr Kate O’ Brien adds that currently the world doesn’t know for how long the vaccines provide immunity against COVID-19. She says,

Whatever vaccines we have in hand right now against COVID-19, we don’t know how long they provide the immunity. We are following people who have received vaccinations to find out whether or not their immune response is durable over time and the length of time which they are protected against disease. For now, we really have to wait for the time to pass to see just how long these vaccines last.

Also Read: Vaccine Explainer: How Does Immunisation Protect Against A Disease?

Can One Still Catch COVID-19 After Getting Vaccinated And Can Infect Others?

Dr Kate O’ Brien says that the clinical trials demonstrated that these vaccines protect against the disease, however, we don’t know yet from the clinical trials whether or not these vaccines protect people from getting infected from COVID-19 or whether or not it protects against transmitting to somebody else. She says,

So that is the really important part of our understanding about what these vaccines can do. With time, as we get more understanding about the vaccines, we will be able to know this.

Common Myths Around COVID-19 Vaccines And Are These Safe?

Putting a stop to all the myths around the vaccines that are floating around, Dr Kate O’ Brien says,

Around the world, whatever vaccines are there against COVID-19 are absolutely safe. All the components that goes into the vaccine are heavily tested to be sure that everything in there is safe for humans. They are first tested on animals to make sure they are safe for humans and then it goes into human clinical trials, where thousands of people receive the vaccine before it is finally authorised for use in general public. Vaccines cannot cause infertility, nor it can change the DNA.

Highlighting the fact Dr Kate O’ Brien says that two of the approved vaccines against COVID-19 are referred to as mRNA vaccines, and there’s no way that the mRNA vaccine can turn into DNA and there is no way that the mRNA vaccine can change the DNA of our human cells. She adds,

What mRNA is that it gives instructions to the body to make a protein. Most vaccines are developed by actually giving the protein or giving the small tiny component of the germ or inactive virus that we are trying to vaccinate against. mRNA is a new approach where we are giving the instructions to our own bodies to make that little part and then our natural immune system responds to it.

Also Read: Coronavirus Explainer: Who Should Not Get Vaccinated? What Are The Possible Adverse Reactions And Other Questions Answered

Why Do We Need To Continue Talking Precautions Even After Vaccination?

Dr Kate O’ Brien says that everyone really needs to continue taking the precautions like handwashing, maintaining social distancing and wearing a mask, while we still learn about what the vaccines can do. She added,

We still don’t know, if vaccines can protect against getting re-infected and transmitting to someone else? And right now, we are in a situation, where there’s still lot of transmission and it is just out of control. So, how long we need to continue taking these precautions is really going to depend on what communities and countries can do to really crush this virus and its transmission. But remember that we really don’t have the evidence yet for using the vaccine in some age groups. We don’t have the evidence for use of vaccines in children, for instance. So, for the time being, those age groups are going to continue be at risk of both disease and infection and being able to transmit to other people.

Dr Kate O’ Brien further says that the second reason for us to continue following all the precautions is that the vaccines are in short supply, so we don’t have enough vaccine yet to protect the community. She adds,

Those are the reasons why we have to continue taking the precautions, especially the masking, social distancing, hand washing and not gathering in public spaces. For how long, we need to continue with these interventions, time is going to tell once we get broad vaccination coverage in the community, when we know more about what vaccine can actually do to prevent infection. It is only then we can slowly start taking our foot off the pedal of these interventions and make sure the transmission doesn’t start to escalate again.

Also Read: Vaccine Hesitancy: What It Means And How We Can Tackle It, Experts Explain

NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (WaterSanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollutionwaste managementplastic banmanual scavenging and sanitation workers and menstrual hygiene


Coronavirus has spread to 195 countries. The total confirmed cases worldwide are 23,96,06,768 and 48,82,051 have died; 20,13,42,617 are active cases and 3,33,82,100 have recovered as on October 15, 2021 at 4:15 am.


3,40,37,592 16,862Cases
3,33,82,100 19,391Recovered
4,51,814 379Deaths
In India, there are 3,40,37,592 confirmed cases including 4,51,814 deaths. The number of active cases is 2,03,678 and 3,33,82,100 have recovered as on October 15, 2021 at 2:30 am.

State Details

State Cases Active Recovered Deaths

65,86,280 2,384

33,157 6

64,13,418 2,343

1,39,705 35


48,29,944 9,246

96,421 1,802

47,06,856 10,952

26,667 96


29,82,399 310

9,607 43

29,34,870 347

37,922 6

Tamil Nadu

26,83,396 1,259

15,451 199

26,32,092 1,438

35,853 20

Andhra Pradesh

20,59,122 540

6,588 27

20,38,248 557

14,286 10

Uttar Pradesh

17,10,008 12

135 4

16,86,976 16


West Bengal

15,79,012 530

7,576 81

15,52,491 601

18,945 10


14,39,311 28

337 1

14,13,885 29



10,33,809 521

4,890 38

10,20,645 477

8,274 6


10,05,614 16

203 4

9,91,841 20



9,54,382 8

42 6

9,45,386 2



8,26,244 34

215 20

8,15,943 14


Madhya Pradesh

7,92,669 12

111 1

7,82,035 11



7,71,035 16

105 158


10,049 174


7,26,016 8

42 6

7,16,313 2



6,68,618 168

4,171 40

6,60,512 207

3,935 1


6,05,847 207

3,646 157

5,96,263 362

5,938 2


6,01,971 33

234 11

5,85,199 16

16,538 6


3,48,406 11

130 4

3,43,141 7



3,43,729 28

175 22

3,36,157 6


Jammu And Kashmir

3,30,834 93

935 11

3,25,473 104


Himachal Pradesh

2,21,113 182

1,387 5

2,16,011 173

3,715 4


1,77,356 68

679 27

1,73,342 39

3,335 2


1,27,259 49

647 4

1,24,763 53



1,22,432 69

1,444 15

1,19,099 84



1,10,719 901

13,601 435

96,744 1,332

374 4


84,295 4

110 8

83,369 12



82,734 87

892 31

80,411 115

1,431 3


65,295 10

32 5

64,443 15


Arunachal Pradesh

54,958 4

202 22

54,476 26



31,722 6

224 1

31,108 7



31,516 9

230 8

30,613 17



20,867 6

44 2

20,615 4


Dadra And Nagar Haveli


3 1

10,668 1




2 0



Andaman And Nicobar Islands

7,640 3

10 1

7,501 2


Coronavirus Outbreak: Full CoverageTesting CentresFAQs

1 Comment

1 Comment

  1. Anuj kumar

    May 19, 2021 at 6:03 am

    I am joing for Bihar in district gopalganj covid working joining

Leave a Reply

Your email address will not be published. Required fields are marked *

Highlights From The 12-Hour Telethon

Leaving No One Behind

Mental Health


Join Us