• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
HealthCoronavirus

Do COVID vaccines stop coronavirus from spreading or just make you less sick?

By
Sy Mukherjee
Sy Mukherjee
Down Arrow Button Icon
By
Sy Mukherjee
Sy Mukherjee
Down Arrow Button Icon
February 2, 2021, 9:55 AM ET

COVID vaccines have their work cut out for them. The various candidates from Pfizer/BioNTech, Moderna, Johnson & Johnson, and AstraZeneca have been the main players (particularly Pfizer and Moderna as the only two companies with an FDA emergency-authorized shot). But there’s a crucial mystery still left to unravel: Do these vaccines simply stop you from getting really sick, or can they actually stop transmission of the coronavirus itself?

Unfortunately there isn’t anything approaching a clear-cut answer to that yet. The rapid production timeline for these immunizations means we need to wait and see all the data. But vaccination is still crucial in the fight against the pandemic despite the unknowns, according to public health experts, and fairly typical when it comes to immunization campaigns.

In order to understand why, it’s important to know how a virus spreads and what vaccines really do.

You see, unlike bacteria, which can exist without infiltrating a host cell, viruses need to hack into your biological machinery in order to do their bidding. The coronavirus latches on to cells via a mechanism called a “spike protein,” and that’s how it replicates itself. It literally turns your body into a disease manufacturing plant.

This is what makes viruses so tricky. They’re significantly smaller than bacteria and, by way of their relative simplicity, can be difficult to contain.

A vaccine’s main purpose is to create an immune response. You’re essentially training up your cells so the immune system is ready once the villainous pathogen smashes through the door.

That doesn’t mean that you won’t get infected, or maybe even get sick from COVID if you do contract the coronavirus. But studies have shown that currently available COVID vaccines can, at the very least, weaken the virus enough to stave off serious and deadly illness.

Achieving “sterilizing immunity,” which prevents a pathogen from causing new infections in other people (including COVID cases in which someone may be asymptomatic or just mildly sick) is the ultimate goal. After all, one person’s asymptomatic or mild COVID sickness could easily turn into a high-risk individual’s death sentence if the person contracts the virus.

But with more data needed on how effective these vaccines are at preventing coronavirus transmission, the message from public health officials is clear: Get the vaccine once you qualify in order to weaken the virus and lower the chances of spreading it to others.

As frustrating as the uncertainty is, it’s nothing new in the world of vaccines. For instance, the vaccine that guards against the whooping cough is highly effective at making sure you don’t get extremely sick but not so much when it comes to spreading the underlying pathogen. But other vaccines such as the one for stomach-churning rotavirus help prevent transmission while not necessarily making someone who catches the bug less sick.

Despite the X factors, the overwhelming medical consensus is that it’s better to get a vaccine when you can, since at the very least it will protect you and may protect many others.

About the Author
By Sy Mukherjee
See full bioRight Arrow Button Icon

Latest in Health

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
Fortune Secondary Logo
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Health

Healthsleep
8 Best Firm Mattresses in 2026: Tested and Reviewed by Sleep Experts
By Christina SnyderFebruary 27, 2026
20 hours ago
HealthFood and drink
Chains like Sweetgreen and Chipotle are finally realizing they need to look beyond the ‘slop bowl’
By Phil WahbaFebruary 27, 2026
23 hours ago
chat
Healthchat
Here are the 7 rules of group chats, including how to leave when you’ve had enough
By Kelvin Chan and The Associated PressFebruary 27, 2026
1 day ago
will
CommentaryAdvertising
I’m one of America’s top pollsters and I’ve got a warning for the AI companies: customers aren’t sold on ads
By Will JohnsonFebruary 27, 2026
1 day ago
Healthsleep
5 Best Latex Mattresses in 2026: Tested and Reviewed by Sleep Experts
By Christina SnyderFebruary 26, 2026
2 days ago
dolly
Lawphilanthropy
Dolly Parton’s Tennessee philanthropy kicks up a notch with renaming of East Tennessee Children’s Hospital
By James Pollard and The Associated PressFebruary 26, 2026
2 days ago

Most Popular

placeholder alt text
Success
Japanese companies are paying older workers to sit by a window and do nothing—while Western CEOs demand super-AI productivity just to keep your job
By Orianna Rosa RoyleFebruary 27, 2026
1 day ago
placeholder alt text
Success
Walmart exec says U.S. workforces needs to take inspiration from China where ‘5 year-olds are learning DeepSeek’
By Preston ForeFebruary 27, 2026
1 day ago
placeholder alt text
Law
China's government intervenes to show Michigan scientists were carrying worms, not biological materials
By Ed White and The Associated PressFebruary 26, 2026
2 days ago
placeholder alt text
Commentary
'The Pitt': a masterclass display of DEI in action 
By Robert RabenFebruary 26, 2026
2 days ago
placeholder alt text
Economy
Come 2030, the U.S. deficit will be worth 5.9% of GDP—more than spending on Social Security, and equal to major health programs
By Eleanor PringleFebruary 26, 2026
2 days ago
placeholder alt text
Personal Finance
Current price of gold as of February 27, 2026
By Danny BakstFebruary 27, 2026
1 day ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.