After the Second COVID-19 Vaccine, How Long Does it Take to Develop Full Immunity

Gaurav has just got his COVID-19 vaccine second dose. But he is still a little worried. He is wondering if he is completely safe now. Does it take time to develop full immunity to COVID-19? Is it even possible to develop full immunity? How long would he have to wait before he has developed full immunity to COVID-19?

These questions are a bit complex to answer. But by looking at proper research and studies conducted across the globe, it is possible to arrive at a satisfactory answer. Let’s try to do that today.

The Authorized Vaccines

According to the Food and Drug Administration (FDA), there are three authorized COVID-19 vaccines applicable for emergency use. Two of these vaccines are:

• Pfizer-BioNTech
• Moderna Vaccines

Both of these vaccines use mRNA technology to help individuals develop their immune system to SARS-CoV-2, which is the coronavirus that causes COVID-19. Both of these vaccines also need two doses.

Further, experts believe that the immunity to the virus kicks in after the second dose. And for that to happen, the vaccine works by introducing the immune system to the spike protein, which is part of the new coronavirus.

The spike protein is found on the viral surface. It helps the virus bind to and enters host cells in the body. The immune system steps in here as it has a memory and uses the vaccine to analyze and store information about the spike protein.

After that, the immune system can draw upon the collected information to protect the host body if it is exposed to the actual virus in the future. This being said, it should be noted that immunity doesn’t happen immediately after vaccination.

It can take around 2 weeks for the body to build up immunity. This means that one can still become ill during this particular time frame. Let’s also look at how effective these vaccines are after getting the second dose.

Effectiveness of Pfizer-BioNTech

Clinical trials were conducted to evaluate the effectiveness of the vaccine after 1 week of getting the second dose. In those trials, it was concluded that the vaccine was 95% effective at preventing COVID-19 after a week.

Effectiveness of Moderna

Clinical trials were conducted after two weeks of participants receiving their second dose. During those trials, it was found that the vaccine was 94.1% effective at preventing COVID-19.

How Long Should One Wait between Doses?

Ideally, the time period between the two doses for both of the two COVID-19 vaccines are:

• Pfizer-BioNTech: The second dose is given 3 weeks after the first dose
• Moderna: The second dose is given four weeks after the first dose

The Requirement of Two Doses

It has been concluded from several studies that both vaccines produce a weak immune system response after just one dose. To get a stronger immune response, it is important for the individual to get a second vaccine dose.

Because of this, two doses of the Pfizer-BioNTech and Moderna vaccines are required. You can also think of it as the first dose starting to build protection and the second dose reinforcing the protection.

There are also some COVID-19 vaccines that only require a single dose. An example of this type of vaccine was developed by Johnson & Johnson. The reason why this vaccine works in a different manner is that it uses a different type of technology than the Pfizer-BioNTech and Moderna vaccines.

The Immunity after the First Vaccine Dose

Studies have found that some immunity is generated after the first dose of the vaccine. Let’s look at details regarding this for the two popular COVID-19 vaccines.

• Pfizer-BioNTech

In the case of the Pfizer-BioNTech vaccine, effectiveness of 52% was reported between the first and the second dose of this vaccine. The actual vaccine effectiveness after the first dose might even be higher than this.

In keeping with the same train of thought, scientists in the United Kingdom have also seen that the actual effectiveness was closer to 89% – 91% after 15 or more days of getting the first dose.

• Moderna

A detailed study on the effectiveness of the FDA of the Moderna vaccine was conducted after only a single dose of vaccine. In that study, researchers found that vaccine effectiveness was 50.8% up to 14 days after the vaccine. After that, the effectiveness was increased to 92.1%

Will Immunity be Affected if I Wait for Too Long between Two Doses?

Gaurav has a friend who waited longer than the recommended amount before getting the two vaccine doses. He is wondering whether that is the right thing to do or not.

According to the Centers for Disease Control and Prevention (CDC), the current recommendation is to wait for 3 weeks before getting the second dose of Pfizer-BioNTech. For the Moderna vaccine, the waiting period is around 4 weeks.

However, sometimes it can be quite unavoidable to get the vaccine within a limited time frame. However, irrespective of the reason for the delay, the one thing you need to know is that there is some wiggle room for this. It shouldn’t affect your immunity even if you get the second dose a little later than expected.

Even if you have been delayed, make sure that this delay is not more than 6 weeks. The impact of delaying the second dose of vaccine is not known beyond that. This is why you should not intentionally delay getting the second dose of your vaccine.

Some experts do speculate that the effectiveness of the vaccine can be lower if the vaccine is delayed for longer than the recommended amount of time.

How Long Does Immunity Last after Getting the Vaccine?

The COVID-19 vaccines have only been around for a very short amount of time. Because of this, it is not exactly known how long immunity will last after being vaccinated. This is valid for both one-dose and two-dose vaccines.

This is one area where studies are being conducted all across the globe. Gaurav desperately wants to know the answer to this question because it would directly have a lot of impact on not just his life but of everybody else’s in the world.

Irrespective of this, the one thing Gaurav is thankful about is that he got vaccinated at the right time. Experts are even predicting the third wave of COVID-19. This wave can also be very deadly. And the only way to protect oneself is by getting vaccinated against COVID-19 at the right time.

I’m Vaccinated. Should I Still Take Precautions?

Gaurav is completely vaccinated. He is wondering what that means for him. Should he still follow precautions? f yes, then what precautions should he follow?

Let’s help Gaurav out with that.

• Wear a mask that covers your nose and mouth whenever you are in a public place
• Practice regular hand washing behavior whenever you are out, after coughing, after sneezing, or after using the bathroom
• Practice physical distancing by staying at least 6 feet away from other people
• Avoid all crowded areas as much as possible

And above all, consult a doctor in case of experiencing any symptoms like coughing, headaches, fever, and cold.