How Long Does It Take to Develop Full Immunity After the Second COVID-19 Vaccine?

In this post of How long Does It Take to develop full immunity after the second covid-19 vaccine. There are many different COVID-19 vaccines in development worldwide. In the USA, the Food and Drug Administration (FDA) has up to now authorized three COVID-19 vaccines for emergency usage.

Two of these vaccines are the Pfizer-BioNTech and Moderna vaccines, which use mRNA technologies to help your immune system generate immunity to SARS-CoV-2, the coronavirus that causes COVID-19.

Both of these vaccines require two doses. It’s after receiving your next dose your resistance to the virus fully kicks in. You may be wondering how long after the second dose you have complete immunity.

In this article, we’ll take a deeper dive into everything you need to know about resistance with all the Pfizer-BioNTech and Moderna vaccines.

How long does it take to have Develop immunity after the second vaccine dose?

Both the Pfizer-BioNTech and Moderna vaccines work by introducing your immune system to a part of their new coronavirus called the spike protein. This protein is found on the surface. It’s used to assist the virus bind to and enter host cells inside the body.

Since your immune system includes a memory, then it may use the vaccine to analyze and store information about the spike protein. It may then draw upon this information to protect you when you are subjected to the actual virus in the future.

But, immunity doesn’t happen immediately after maternity. Actually, it generally takes about two weeks for your body to develop resistance. Because of this, you can still become sick during this time period.

Now that we have discussed how long it normally takes to have immunity, let us take a look at the effectiveness of this Pfizer-BioNTech and Moderna vaccines in the weeks after the next dose.


The Pfizer-BioNTech clinical trial assessed vaccine efficacy 1 week later participants had gotten their next dose.


The Moderna clinical trial looked at vaccine effectiveness 2 weeks after participants had received their next dose. At this point, the vaccine has been found to be 94.1 percent successful at preventing COVID-19.

How long do you need to wait between doses?

The Period of Time between the two doses depends upon which of the two vaccines you buy:

Pfizer-BioNTech: The second dose is given 3 months after the first dose.
Moderna: The second dose is given 4 weeks following the initial dose.

Why are two doses needed?

During early testing, researchers discovered that both vaccines generated a weak immune responseTrusted Source after just one dose. But a much stronger immune response was noticed after the second dose.

This is the reason two doses of the Pfizer-BioNTech and Moderna vaccines are necessary. Think of it like this: The first dose starts building protection, while the next dose strengthens that security.

There are a few vaccines that only need one dose. A good instance of that is that the vaccine manufactured by Johnson & Johnson.

This vaccine uses another kind of technology than the Pfizer-BioNTech and Moderna vaccines. After reviewing effectiveness and safety information from clinical trials, the FDA authorizedTrusted Source that the Johnson & Johnson vaccine for emergency use.

Do you have immunity after the first vaccine dose?

Some resistance is generated following the first dose of this vaccine. This information has been reported can be different for the two vaccines.


For the Pfizer-BioNTech vaccine, an effectiveness of 52 percent was reported involving the time of the first and second doses. However, vaccine effectiveness after the first dose might in fact be higher than this.

Another analysis by scientists in the United Kingdom estimated that vaccine effectiveness was closer to 89 to 91 percent 15 days or longer after the initial dose.

Furthermore, a 2021 study of this vaccination campaign in Israel found significant reductions in COVID-19 cases after a dose of this Pfizer-BioNTech vaccine.


In this case, researchers discovered that vaccine efficacy was 50.8 percent up to 14 days after and was 92.1 percent beyond this period.

Can your immunity be affected if you wait too long between the two doses?

The Centers for Disease Control and Prevention (CDC) currently recommends you get your next dose as close to the 3-week (Pfizer-BioNTech) or even 4-week (Moderna) waiting interval as you can.

But sometimes, delays in the vaccine supply chain or unexpected weather events can keep you from receiving your second vaccine directly on time. Fortunately, there’s some wiggle room for it, and getting your next dose a little later than anticipated should not impact your immunity.

According to the CDC’s guidelines, it’s best to not get your second dose over 6 weeks after you obtained your initial dose.

The impact of delaying the next dose any longer is unknown currently.

How long does immunity last after getting the vaccine?

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

Going forward, scientists will continue to study the different COVID-19 vaccines and how long their immunity lasts.

Even though we don’t know how long protection from COVID-19 vaccines lasts, it’s still very important to receive your vaccination when it’s available to you.

This is because getting vaccinated can prevent you from getting COVID-19. Even if you do get the disease, you’ll have a much lower risk for developing a serious or life threatening illness.

Can the vaccine protect you against other strains of the new coronavirus?

Within the last several months, fresh strains, or variations, of SARS-CoV-2 have already been identified. There have been concerns about about how effective the vaccines are against these new versions. Two new breeds you may have heard a lot about are:

Initial data indicates that these vaccines may be less effective against the South African strain.

One report tested antibodies generated by the Pfizer-BioNTech vaccine from a test virus containing the spike protein mutations found in the Southern African variant. In comparison to an early strain of this novel coronavirus, antibody neutralization of this virus was two-thirds weaker.

A similar report appeared at the capacity of radicals generated from the Moderna vaccine to neutralize viruses. While viruses from the U.K. version were neutralized, researchers saw a 6.4-fold drop in neutralization for its Southern African strain.

It is important to note that this remains a developing area of study. Researchers will continue to look into the impact that emerging breeds have on current and future COVID-19 vaccines.

Do you still need to take precautions after being vaccinated?

If you’ve received both doses of this vaccine, it is important to continue to take precautions, such as:

  • Wearing a mask. Wear a mask that covers your mouth and nose when you are around people beyond your household.
  • Hand-washing. Hand-washing is particularly important after being out in people, after coughing and coughing, and after using the bathroom.
  • Practicing physical distancing. Try to stay at least 6 feet apart from people outside your own household.
  • Avoiding crowded areas. Places which are crowded or poorly ventilated may make it simpler to contract and transmit the virus.

These precautions are important because we now do not know whether those who’ve been vaccinated may still spread the virus to others, even when they don’t develop symptoms.