Vaccinated People Less Likely To Have Severe COVID-19 vs Unvaccinated

By Shreya Gupta +2 more


Despite the various variants of the coronavirus (like the Delta variant), the world as a whole is slowly but surely moving away from the pandemic. Around the globe vaccination rates are increasing, while Covid-19 related infection, hospitalization and death rates are decreasing.

Along with Covid-19 protocols like hand hygiene, respiratory etiquettes, physical distancing, vaccination is quickly becoming the most powerful tool against Covid-19. There have been many studies over the past year noting the difference between people vaccinated for Covid-19 vs those who are unvaccinated. Vaccination has been shown to drastically lower your risk of getting severe symptoms upon infection, even if breakthrough infections are possible.

What Are Breakthrough Infections?

Vaccines are not 100% successful, even when fully vaccinated (for Covid-19 or anything else) there is still a small chance you can still get infected. When someone catches the disease that they are fully vaccinated for, it is commonly known as a breakthrough infection. You may be thinking, well then, what’s the point of getting vaccinated if breakthrough infections are possible?

The fact is that currently, hospitalizations and deaths related to COVID-19 are made up overwhelmingly of unvaccinated people. According to the CDC in the USA, deaths and hospitalizations of fully vaccinated people make up just 0.01% of total vaccinated cases. To put that into perspective, if 1 million people got vaccinated, only 100 of those would experience hospitalization or death. The rate of the same in unvaccinated people is much higher. 

You have a lower risk of catching COVID-19 if you’re vaccinated and even if you happen to suffer from a breakthrough infection, you’re still at a much lower risk of hospitalisation and death. To be clear, these facts also take into account early data that includes Delta variant cases.

The Delta Variant and COVID-19

By now it has become common knowledge that all viruses and bacteria mutate and evolve with time in response to vaccines and medicines. Sometimes (not always) these mutations can lead to variants that are more harmful or spread more easily. That happens to be the situation for the Delta variant of the COVID-19 coronavirus. 

Many countries started easing on pandemic protocols only to get slammed by new Delta variant cases. We know that vaccines have lower effectiveness with breakthrough Delta variant cases. But still, most vaccines provide substantial protection against the Delta variant than not being vaccinated at all. 

Some previously discovered data on Delta variant cases:

  • The Delta variant is known to be much more transmissible.
  • Early studies suggest that it is more likely to cause hospitalization.
  • Other studies indicated that Delta variant cases have a higher risk of death.
  • The Delta variant also causes more severe symptoms than the original variant.

The only protection we have against the deadly Delta variant is vaccination. The effectiveness of vaccination may drop to 39% – 95% as compared to its effectiveness against the Alpha variant. But that is still a massive leg-up from being unvaccinated.

Vaccinated vs Unvaccinated – What Are The Differences

People who are vaccinated are not only less likely to get infected (by any variant) but are also less likely to experience severe symptoms. It has been reported that fully vaccinated people experience much milder symptoms (runny nose, congestion, etc) compared to unvaccinated people. Obviously, people with weaker immune systems are at a higher risk of severe disease from COVID-19, regardless of vaccination status. But unvaccinated people will have an increased risk of suffering severe symptoms caused by the Delta variant, including fever, difficulty breathing and headaches.

More severe symptoms of COVID-19 will often lead to an increased risk of hospitalization. Unvaccinated people are more likely to need hospital treatment when infected with the coronavirus and its variants. Several factors play into hospitalization rates, such as age, weaker immune systems, other comorbid conditions and which variant infects you. But vaccination seems to benefit people against the Delta variant at some level, regardless of other factors.

Here’s a quick summary to get a gist of vaccination effectiveness against the Delta variant:

  • When fully vaccinated you are less likely to get infected with the Delta variant (please note, you do not have 100% protection!).
  • Even if you do go through a breakthrough case, you are less likely to have severe symptoms.
  • This reduces your risk of hospitalization as well.
  • All of these combined leads to a lower risk of death from not just the Delta variant but also the older variants.

Also Read: Omicron Variant vs Vaccine Efficacy


Many people are afraid of the current situation. People fear not only the virus and losing loved ones but also fear vaccine reactions. But getting COVID-19 can lead to major complications while vaccine reactions are mild and last only a couple of days. The enormous body of evidence is painting a clear picture – vaccination is better overall, regardless of variant. It is best to avoid sensationalized, clickbait news sites that try to instil fear about ‘increasing breakthrough infections!’. Breakthrough infections are expected and it is nothing to get agitated about. Besides this, their occurrence is very low. Fully vaccinated people can increase their protection against the Delta variant (and other variants) by continuing to wear a mask, maintain social distance and wash hands regularly. If you are unvaccinated, you need to do the same but also get your vaccination done at the earliest.

Also Read: Omicron Variant: Latest News & Updates

Disclaimer: The information included at this site is for educational purposes only and is not intended to be a substitute for medical treatment by a healthcare professional. Because of unique individual needs, the reader should consult their physician to determine the appropriateness of the information for the reader’s situation.

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