What is the efficacy of vaccines in providing protection? Is it still possible to contract the infection after vaccination?

Hello! Many people have similar questions about vaccines. Let me clarify them for you, trying to explain in simple terms.

How Effective Are Vaccines?

First, let's understand one concept: no vaccine offers 100% protection.

You can imagine a vaccine as a high-tech "bulletproof vest" for your immune system.

Highly Effective Vests: For vaccines like those against measles and mumps, the protective efficacy is very high, usually over 90%. Once 'worn,' most viral 'bullets' are blocked, and you remain safe.
Different Types of Vests: Different vaccines use different technologies and target different viruses, so the 'material' and 'thickness' of the 'vest' vary, leading to differences in protective efficacy. For example, some vaccines have 80% efficacy, while others have 90%.

What does this percentage mean? For instance, if the protective efficacy is 90%, it simply means that under the same risk of infection, if 100 unvaccinated people get sick, only about 10 vaccinated people might get sick.

Key Takeaway: The primary and most crucial role of vaccines is to prevent severe illness and death. Even if the 'bulletproof vest' doesn't completely block the 'bullet' (meaning an infection occurs), it can greatly reduce the bullet's impact, causing at most a minor scratch (mild symptoms) rather than a fatal blow (severe illness or death).

Can You Still Get Infected After Vaccination?

The answer is: Yes, it's possible. This situation is called a "breakthrough infection".

This might sound a bit discouraging, but don't worry, let's understand it using the 'bulletproof vest' analogy again.

A Vest Isn't Invincible: Even if you wear a top-tier bulletproof vest, if the enemy's firepower is too strong (e.g., a very high viral load environment), or if a bullet happens to hit a gap not covered by the vest (minor differences in individual immune systems), you can still get injured. This is what a breakthrough infection is.
Vastly Different Injury Severity: This is the most crucial point! For someone without a 'vest' (unvaccinated), getting hit might mean severe injury or even death. But for someone wearing a 'vest' (vaccinated), even if a breakthrough infection occurs, in most cases, the symptoms will be much milder, possibly like a common cold, with faster recovery and a significantly reduced chance of hospitalization.

In Summary

To put complex matters simply:

Is Vaccination Worth It? Absolutely! It is currently the most effective scientific means to protect ourselves and our families.
What is the Purpose of Vaccines? The main goal is to prevent severe illness and death. Think of it like a seatbelt in a car; it can't guarantee you won't get into an accident, but it can greatly save your life if one occurs.
Is Everything Fine After Vaccination? No. During a viral outbreak, even if vaccinated, good habits like wearing masks in crowded places and frequent handwashing remain important. This is like both wearing a bulletproof vest and knowing how to find cover – double protection is safer.

I hope this explanation helps you!