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How long does protection last after a COVID-19 vaccine?

How long does protection last after a COVID-19 vaccine?

This article was published on
May 6, 2021

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27 April 2022: The duration of protection after the COVID-19 vaccine has been shown to vary for people and by vaccine received and number of doses. Protection from infection also differs based on the COVID-19 variant that someone is exposed to. 

According to a pre-print published in March 2022, which has not yet been peer-reviewed, a study was carried out in Qatar to estimate the how long protection lasts from an mRNA vaccine against COVID-19 Omicron BA.1 and BA.2 subvariants (two of the main Omicron subvariants). 

Even though BA.2 (the current dominant variant) spreads more quickly than BA.1, mRNA vaccines have been shown to provide similar protection against symptomatic infection from both sub-variants. In the preprint article carried out in Qatar, the Pfizer-BioNTech vaccine was about 50% effective at preventing a new BA.1 COVID-19 infection in the first three months after the second dose, but declined to about 10% after the first three month period. The results were nearly exactly the same for protection against BA.2 from Pfizer-BioNTech. 

There was, however, a small difference in how protective a Pfizer-BioNTech booster shot was by subvariant. After a booster dose, the protection against BA.1 rebounded to high levels (59.9%) and started to wane starting the second month after the booster dose. For BA.2, on the other hand, the protection rebounded to much higher levels (43.7%), but not as high as protection against BA.1. 

With regards to protection against hospitalization and death due to Omicron infections, durable protection was seen across vaccines for both variants, particularly after a booster; after a second dose of an mRNA vaccine, protection was 70%, whereas after a booster, it was over 90%. The study observed similar patterns of protection across both subvariants with the Moderna vaccine. 

There is no clear answer yet on how long the protection from COVID-19 infection after vaccination will last as the virus changes over time. As new evidence becomes available and as immunity wades, it might be possible that boosters or annual vaccines become necessary.

9 March 2022: A new analysis in The Lancet published in March 2022 found that four WHO-approved COVID-19 vaccines – Pfizer, Moderna, J&J, and AstraZeneca – retain nearly all of their ability to prevent severe disease up to six months after full vaccination. 

The overall level of protection against (detected) infection from COVID-19 infection fell by about 21 percentage points on average from one month to six months after vaccination, from 90% to 69% protection against severe disease only fell 10 percentage points.

When measuring protection against symptomatic illness, the drop was bigger at 24.9 percentage points on average, which includes both mild and severe symptomatic illness across all ages. When narrowed down to just older individuals, the percentage point decrease from one month to six months was 32.

Researchers found that right after a booster shot of the Pfizer vaccine (two weeks post-vaccine), the booster cuts the risk of infection with symptoms by about 50%. 

A separate analysis from the United Kingdom found that this protection may decline more to 40% four months after the booster shot. 

Recent research from Israel found that four months after a fourth shot in people over 60, antibody levels increase, protection against the Omicron variant doubles, and prevention against hospitalization triples. Other research has shown that though additional COVID-19 vaccines doses increase protection, they also seem to “hit a ceiling,” meaning that further doses will probably only recover the immunity (protection) lost over time. More research is needed.

27 April 2022: The duration of protection after the COVID-19 vaccine has been shown to vary for people and by vaccine received and number of doses. Protection from infection also differs based on the COVID-19 variant that someone is exposed to. 

According to a pre-print published in March 2022, which has not yet been peer-reviewed, a study was carried out in Qatar to estimate the how long protection lasts from an mRNA vaccine against COVID-19 Omicron BA.1 and BA.2 subvariants (two of the main Omicron subvariants). 

Even though BA.2 (the current dominant variant) spreads more quickly than BA.1, mRNA vaccines have been shown to provide similar protection against symptomatic infection from both sub-variants. In the preprint article carried out in Qatar, the Pfizer-BioNTech vaccine was about 50% effective at preventing a new BA.1 COVID-19 infection in the first three months after the second dose, but declined to about 10% after the first three month period. The results were nearly exactly the same for protection against BA.2 from Pfizer-BioNTech. 

There was, however, a small difference in how protective a Pfizer-BioNTech booster shot was by subvariant. After a booster dose, the protection against BA.1 rebounded to high levels (59.9%) and started to wane starting the second month after the booster dose. For BA.2, on the other hand, the protection rebounded to much higher levels (43.7%), but not as high as protection against BA.1. 

With regards to protection against hospitalization and death due to Omicron infections, durable protection was seen across vaccines for both variants, particularly after a booster; after a second dose of an mRNA vaccine, protection was 70%, whereas after a booster, it was over 90%. The study observed similar patterns of protection across both subvariants with the Moderna vaccine. 

There is no clear answer yet on how long the protection from COVID-19 infection after vaccination will last as the virus changes over time. As new evidence becomes available and as immunity wades, it might be possible that boosters or annual vaccines become necessary.

9 March 2022: A new analysis in The Lancet published in March 2022 found that four WHO-approved COVID-19 vaccines – Pfizer, Moderna, J&J, and AstraZeneca – retain nearly all of their ability to prevent severe disease up to six months after full vaccination. 

The overall level of protection against (detected) infection from COVID-19 infection fell by about 21 percentage points on average from one month to six months after vaccination, from 90% to 69% protection against severe disease only fell 10 percentage points.

When measuring protection against symptomatic illness, the drop was bigger at 24.9 percentage points on average, which includes both mild and severe symptomatic illness across all ages. When narrowed down to just older individuals, the percentage point decrease from one month to six months was 32.

Researchers found that right after a booster shot of the Pfizer vaccine (two weeks post-vaccine), the booster cuts the risk of infection with symptoms by about 50%. 

A separate analysis from the United Kingdom found that this protection may decline more to 40% four months after the booster shot. 

Recent research from Israel found that four months after a fourth shot in people over 60, antibody levels increase, protection against the Omicron variant doubles, and prevention against hospitalization triples. Other research has shown that though additional COVID-19 vaccines doses increase protection, they also seem to “hit a ceiling,” meaning that further doses will probably only recover the immunity (protection) lost over time. More research is needed.

Current research shows that immunity lasts at least about 6 months for mRNA COVID-19 vaccines (the Pfizer vaccine and the Moderna vaccine). Some researchers estimate that immunity against COVID-19 following vaccination will last longer, but because the virus is so new, experts are not sure if protection might wane. More research is needed to better understand how long people will likely be protected after vaccination and how it might vary across different individuals and across different vaccines.

Current research shows that immunity lasts at least about 6 months for mRNA COVID-19 vaccines (the Pfizer vaccine and the Moderna vaccine). Some researchers estimate that immunity against COVID-19 following vaccination will last longer, but because the virus is so new, experts are not sure if protection might wane. More research is needed to better understand how long people will likely be protected after vaccination and how it might vary across different individuals and across different vaccines.

Publication

What our experts say

Some vaccines, such as those for measles, mumps, and rubella, give a person lifetime protection. Others, like the flu vaccine, require a person to get a new shot every year. That's because with some shots, immunity can wane. We’re not sure yet which type of vaccine the COVID-19 vaccines will be, but the best estimate is the mRNA vaccines currently in use (the Pfizer-BioNTech and Moderna vaccines) are likely to last for one to three years, and that most vaccines will need to be recurring.

If “booster” shots are needed, or if the COVID-19 vaccines are needed every year, they should be relatively easy to produce—especially mRNA vaccines in use. 

We don’t know how long vaccines work against COVID-19 yet, because they have not been in use for very long. However, Pfizer-BioNTech said that the ongoing phase three trial of its mRNA vaccine shows that strong protection lasts for at least 6 months for individuals who are vaccinated.

The Pfizer vaccine has 91.3% efficacy against COVID-19 six months after someone gets their second dose. Similarly, evidence for the Moderna vaccine shows 94% effectiveness six months following the second dose.

Importantly, estimates on protection could also change if there are more serious variants that are better at infecting vaccinated people. The vaccines currently in use have been shown to be effective against most, but not all, COVID-19 variants—particularly those circulating in the United States. But as the virus keeps changing naturally, variants could emerge that the vaccines are less effective against.

The promising six-month data is an important and helpful milestone nonetheless. It tells experts the vaccines are working, and that protection will last longer than 6 months. Experts estimate that the Pfizer and Moderna vaccines may provide good protection from COVID-19 for one to three years. Manufacturers will continue to monitor the effectiveness of their vaccines, and Moderna and Pfizer-BioNTech have launched preliminary studies of booster shots.

Right now there is no good data on how long protection against COVID-19 lasts for other vaccines, like the Johnson & Johnson or AstraZeneca vaccines. As that data comes out we will be able to know more about how much other vaccines protect against the virus over time. 

Some vaccines, such as those for measles, mumps, and rubella, give a person lifetime protection. Others, like the flu vaccine, require a person to get a new shot every year. That's because with some shots, immunity can wane. We’re not sure yet which type of vaccine the COVID-19 vaccines will be, but the best estimate is the mRNA vaccines currently in use (the Pfizer-BioNTech and Moderna vaccines) are likely to last for one to three years, and that most vaccines will need to be recurring.

If “booster” shots are needed, or if the COVID-19 vaccines are needed every year, they should be relatively easy to produce—especially mRNA vaccines in use. 

We don’t know how long vaccines work against COVID-19 yet, because they have not been in use for very long. However, Pfizer-BioNTech said that the ongoing phase three trial of its mRNA vaccine shows that strong protection lasts for at least 6 months for individuals who are vaccinated.

The Pfizer vaccine has 91.3% efficacy against COVID-19 six months after someone gets their second dose. Similarly, evidence for the Moderna vaccine shows 94% effectiveness six months following the second dose.

Importantly, estimates on protection could also change if there are more serious variants that are better at infecting vaccinated people. The vaccines currently in use have been shown to be effective against most, but not all, COVID-19 variants—particularly those circulating in the United States. But as the virus keeps changing naturally, variants could emerge that the vaccines are less effective against.

The promising six-month data is an important and helpful milestone nonetheless. It tells experts the vaccines are working, and that protection will last longer than 6 months. Experts estimate that the Pfizer and Moderna vaccines may provide good protection from COVID-19 for one to three years. Manufacturers will continue to monitor the effectiveness of their vaccines, and Moderna and Pfizer-BioNTech have launched preliminary studies of booster shots.

Right now there is no good data on how long protection against COVID-19 lasts for other vaccines, like the Johnson & Johnson or AstraZeneca vaccines. As that data comes out we will be able to know more about how much other vaccines protect against the virus over time. 

Context and background

COVID-19 vaccines in use are highly effective at preventing COVID-19 infection and severe cases, and early research suggests they should maintain their effectiveness over at least six months. What remains unclear, however, is how long the vaccines will maintain that effectiveness and prevent against COVID-19, if booster shots or new shots may be needed to improve protection, or if vaccines will need to be changed to fight against new variants of the virus.

COVID-19 vaccines in use are highly effective at preventing COVID-19 infection and severe cases, and early research suggests they should maintain their effectiveness over at least six months. What remains unclear, however, is how long the vaccines will maintain that effectiveness and prevent against COVID-19, if booster shots or new shots may be needed to improve protection, or if vaccines will need to be changed to fight against new variants of the virus.

Resources

  1. Measles, Mumps, and Rubella (MMR) Vaccination: What Everyone Should Know (Centers for Disease Control and Prevention)
  2. Pfizer and BioNTech Confirm High Efficacy and no Serious Safety Concerns Through up to Six Months Following Second Dose in Updated Topline Analysis of Landmark COVID-19 Vaccine Study (Pfizer-BioNTech)
  3. Pfizer and BioNTech Conclude Phase 3 Study of COVID-19 Vaccine Candidate, Meeting all Primary Efficacy Endpoints (Pfizer-BioNTech)
  4. How long does immunity last after COVID-19 vaccination? (GAVI, the Vaccine Alliance)Antibody Persistence through 6 Months after the Second Dose of mRNA-1273 Vaccine for Covid-19 (The New England Journal of Medicine)
  5. Vaccines and Related Biological Products Advisory Committee Meeting December 17, 2020: Moderna COVID-19 Vaccine (Food and Drug Administration)
  6. About Variants of the Virus that Causes COVID-19​​ (Centers for Disease Control and Prevention)
  7. Neutralization of SARS-CoV-2 Variants B.1.429 and B.1.351 (The New England Journal of Medicine)
  8. Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera (bioRxiv)
  9. Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England (medRxiv)
  10. Neutralization of SARS-CoV-2 spike 69/70 deletion, E484K, and N501Y variants by 2 BNT162b2 vaccine-elicited sera (bioRxiv)
  11. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression (The Lancet)
  12. SARS-CoV-2 variants of concern and variants under investigation in England (UK Health Security Agency)
  13. Three, four or more: what’s the magic number for booster shots? (Nature)
  14. Preliminary Data Analysis: Effectiveness of the Fourth Dose for Older Adults 60 Years of Age and Older (Israel Ministry of Health)
  15. Fourth dose of COVID vaccine offers only slight boost against Omicron infection (Nature)
  16. Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (medRxiv)
  17. Vaccines protect against infection from Omicron subvariant — but not for long (Nature)
  18. How Long Will COVID-19 Vaccine-Induced Immunity Last? (VeryWellHealth)
  1. Measles, Mumps, and Rubella (MMR) Vaccination: What Everyone Should Know (Centers for Disease Control and Prevention)
  2. Pfizer and BioNTech Confirm High Efficacy and no Serious Safety Concerns Through up to Six Months Following Second Dose in Updated Topline Analysis of Landmark COVID-19 Vaccine Study (Pfizer-BioNTech)
  3. Pfizer and BioNTech Conclude Phase 3 Study of COVID-19 Vaccine Candidate, Meeting all Primary Efficacy Endpoints (Pfizer-BioNTech)
  4. How long does immunity last after COVID-19 vaccination? (GAVI, the Vaccine Alliance)Antibody Persistence through 6 Months after the Second Dose of mRNA-1273 Vaccine for Covid-19 (The New England Journal of Medicine)
  5. Vaccines and Related Biological Products Advisory Committee Meeting December 17, 2020: Moderna COVID-19 Vaccine (Food and Drug Administration)
  6. About Variants of the Virus that Causes COVID-19​​ (Centers for Disease Control and Prevention)
  7. Neutralization of SARS-CoV-2 Variants B.1.429 and B.1.351 (The New England Journal of Medicine)
  8. Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera (bioRxiv)
  9. Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England (medRxiv)
  10. Neutralization of SARS-CoV-2 spike 69/70 deletion, E484K, and N501Y variants by 2 BNT162b2 vaccine-elicited sera (bioRxiv)
  11. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression (The Lancet)
  12. SARS-CoV-2 variants of concern and variants under investigation in England (UK Health Security Agency)
  13. Three, four or more: what’s the magic number for booster shots? (Nature)
  14. Preliminary Data Analysis: Effectiveness of the Fourth Dose for Older Adults 60 Years of Age and Older (Israel Ministry of Health)
  15. Fourth dose of COVID vaccine offers only slight boost against Omicron infection (Nature)
  16. Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (medRxiv)
  17. Vaccines protect against infection from Omicron subvariant — but not for long (Nature)
  18. How Long Will COVID-19 Vaccine-Induced Immunity Last? (VeryWellHealth)

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