What We Know About Vaccine Breakthrough Infections
- Vaccine breakthrough infections are expected. COVID-19 vaccines are effective at preventing most infections. However, like other vaccines, they are not 100% effective.
- Fully vaccinated people with a vaccine breakthrough infection are less likely to develop serious illness than those who are unvaccinated and get COVID-19.
- Even when fully vaccinated people develop symptoms, they tend to be less severe symptoms than in unvaccinated people. This means they are much less likely to be hospitalized or die than people who are not vaccinated.
- People who get vaccine breakthrough infections can be contagious.
CDC is collecting data on vaccine breakthrough infections and is closely monitoring the safety and effectiveness of all Food and Drug Administration approved and authorized COVID-19 vaccines.
Because vaccines are not 100% effective, as the number of people who are fully vaccinated goes up, the number of vaccine breakthrough infections will also increase. However, the risk of infection remains much higher for unvaccinated than vaccinated people.
The latest data on rates of COVID-19 cases, hospitalizations and deaths by vaccination status are available from the CDC COVID Data Tracker.
Is Omicron Less Severe Than Other Variants
Dr. Isaac Bogoch, is an infectious diseases faculty member at the University of Toronto told CTVs News Channel, that some early data from South Africa and Denmark and a few other places have small arrows pointing in the direction that maybe is less severe than other variants.
That would be amazing, he said on Friday. But like anything else, theres no one perfect dataset.
Bogoch said we will probably have a better understanding of the variant in a week or two, when hospitalization data emerges from the U.K. and Denmark.
He said there are significant caveats with the data that is currently available.
It think its premature to conclude that it is indeed less severe, he said. It might be, we hope it is, but you cant plan on hope, youve got to plan for the best here and really get those third doses in.
Bogoch said the Omicron variant is extremely transmissible, and added that COVID-19 is a very challenging virus to control.
He said even if the variant does prove to be less severe, if a large number of people become infected, the small percentage of those who do become sick enough to end up in a hospital could still be a significant amount.
Bogoch said Canada is pretty fragile from a health care capacity standpoint.
It doesnt take too much to really stretch that beyond capacity, he continued. And thats a Canada-wide issue. Thats an issue from coast to coast.
With files from Reuters
Moderna And Pfizer Vaccines Thought To Be Up To 86% Effective Against Hospitalization Caused By Covid
A different CDC report found that the Moderna and Pfizer COVID-19 vaccines are effective against hospitalization caused by COVID-19. The report used data from March to July 2021 and concluded that 2 doses of either vaccine series helped prevent hospitalization over 80% of the time.
About 1,100 people were analyzed to collect this information. Up to 3 months after vaccination, the vaccines were seen to be about 86% effective. After that up to 6 months after vaccination the vaccines were about 84% effective.
These numbers reflect hospitalizations caused by the Delta variant and previous variants. But this study only analyzed hospitalized adults, and it didnt look at the specific effects of the J& J vaccine.
What this means: COVID-19 vaccination lowers the risk of hospitalization from infection.
What this doesnt mean: We dont know how effective the J& J vaccine is at preventing hospitalization. It wasnt included in this study, but its been studied elsewhere.
To read more about this report, click or tap here.
Recommended Reading: How Long Does A Cvs Rapid Test Take
Risk Of Getting Covid
After the first vaccination, you may still get COVID-19 because your immunity to the virus is not yet fully developed. After the second vaccination, there is a much lower risk of becoming ill because you are better protected. That is why it is important to get both vaccinations. Since the protective effect of the first series of vaccines decreases over time, as of autumn 2021 people can get a booster vaccine. Booster vaccinations will be scheduled old to young. This booster vaccination is intended to boost and improve the effectiveness of the initial series of vaccination.
Information on how effective the vaccines are is provided on the page about COVID-19 vaccines. All vaccines prevent people from becoming ill due to the coronavirus. However, the vaccines work in different ways. See also the information provided on Government.nl.
Could One Type Of Vaccine Last Longer Than Another
No one knows for sure whether one vaccine will last longer than another. Instead, one question to ask might be whether Pfizer and Modernas mRNA vaccines, which had an especially robust response, also have potential to be the longest lasting, Dr. Meyer says.
The two mRNA vaccines use a relatively new technology that delivers a tiny piece of genetic code from the SARS CoV-2 virus into the body to provide instructions for making copies of spike proteins that will stimulate an immune response. The Johnson & Johnson vaccine takes a more traditional approach that involves an inactive adenovirus .
The mRNA vaccines are a novel tool that hasnt been widely rolled out with any other virus, and so far in clinical trials they have had a much more robust immune response, Dr. Meyer says. Whatever the answer to the question of which will last the longest, the Pfizer and Moderna mRNA vaccines work similarly, so it seems likely that they will have a similar impact on immunity, she says.
Its also possible that the length of immunity is somewhat dependent on the patient, Dr. Meyer adds. While more research is needed, there could be variations in immune responses from person to person based on such factors as age, medical conditions, and medications they may be taking. Overall, though, the mRNA vaccines appear to be so effective that they level the playing field in terms of achieving protection from infection, says Dr. Meyer.
Don’t Miss: Cvs Test Results How Long Covid
Gauging Effectiveness: Pfizer Vaccine Vs Omicron
Few real-world studies so far have managed to estimate effectiveness for the Pfizer-BioNTech vaccine, and a number of lab studies show that a booster increases antibody production significantly.
The studies are largely laboratory studies that would indicate that levels of antibody induced by boosting will have a noteworthy impact on preventing serious disease, said Schaffner.
A preprint study conducted by Oxford University reported that two doses of the AstraZeneca or Pfizer-BioNTech vaccines offered little protection against infection with the Omicron variant.
However, a real-life study from South Africa found that two doses of the Pfizer-BioNTech vaccine still protected people from severe disease.
Researchers found that two doses provided 70 percent protection against hospitalization and 33 percent protection against infection. This was a drop from about 93 percent and 80 percent, respectively, for the Delta variant.
Dr. Monica Gandhi, an infectious diseases specialist with the University of California, San Francisco, told Healthline that although these lab studies show that antibodies, the bodys main line of defense against the coronavirus, can wane over time or be affected by mutations along the viruss spike protein, vaccines were able to generate other types of immune cells to fight off infection.
When Can I Get The Coronavirus Vaccine
Now that the Food and Drug Administration has issued emergency use authorizations for COVID-19 vaccines, vaccines are being distributed across the United States.
If you are a Johns Hopkins Medicine patient, visit our COVID-19 Vaccine Information and Updates page for current information on getting vaccinated. Your states health department website can also provide updates on vaccine distribution in your area.
Coronavirus Email Alerts
Read Also: How Much Is A Cvs Covid Test
How Effective Are They
Both vaccines have been approved by the Cuban regulator, though they started being rolled out in May before authorisation had been granted in response to a rise in cases. There have been concerns about a lack of information on their safety and efficacy.
On November 1 2021, a preprint was finally published of a Soberana phase 3 trial that included 44,031 participants. The results suggest that two doses of Soberana 02 with a booster of Soberana Plus are together 92% protective against symptomatic COVID. The preprint notes that during the trial, the vaccine was most likely being tested against beta or delta two variants of the coronavirus that other vaccines have found harder to control.
Before this, a phase 1 study of giving Soberana Plus to people who had already had COVID was published in September. This was testing the effects of Soberana Plus as a booster to natural rather than vaccine-induced immunity. It showed no safety issues and stimulated a good immune response when used in this way though the study was small, involving just 30 participants.
For Abdala, the only phase 3 trial data available was issued by Cuban press releases in and 2021. The three-dose schedule is also reportedly 92% protective against symptomatic COVID as well as allegedly fully protective against severe disease and death.
Evidence Of Booster Vaccination Performance
In several jurisdictions, booster vaccination has been authorized by regulatory authorities and added to the product labels of BNT162b2, mRNA 1273 and Ad26.COV2.S. In addition, for ChAdOx1-S and CoronaVac, COVID-19 vaccine BIBP, BBV152 and NVX-CoV2373 vaccines, clinical trial data of booster doses are available. All studies to date show a strong anamnestic immunological response achieving or improving upon the peak antibody levels following the primary immunization series, but with insufficient data and too little follow-up to assess the kinetics and duration of the response. Both homologous and heterologous booster regimens are immunologically effective.
Because no correlate of protection has yet been defined, it is not possible to predict with high confidence vaccine performance of these heterologous schedules based on the immune response. Vaccine effectiveness data for a booster dose are being published from an increasing number of countries, but remain limited in follow-up time. All studies demonstrate an improvement in protection against infection milder disease as well as severe disease and death .
Safety and reactogenicity studies are based on small-scale clinical trials and post-licensure data with limited follow-up. Overall, they show a similar safety profile to that observed after the second dose in the primary series. Regulatory authorities and advisory bodies have thus assessed a favourable benefit risk ratio of booster vaccination at an individual level.
Also Check: Cost Of Cvs Covid Test
Two Doses Of J& j Vaccine Found To Provide Strong Protection Against Moderate
This study looked at the effects of a J& J booster shot given 56 days after a first dose. In the study, the two shots together provided about 94% protection against moderate-to-severe COVID-19 symptoms in the U.S. and 75% protection globally. They were also found to provide 100% protection against severe COVID-19 about 14 days after vaccination.
Data also shows that when a J& J booster shot is given 6 months after a first dose, antibody levels are about 12 times higher 4 weeks after the booster is given. Antibodies are substances our body makes in response to a foreign invader like COVID-19. Since the vaccines mimic infection, they prompt our immune systems to create antibodies that can recognize and attack the virus if we become infected.
But the single shot is still thought to be effective including against the Delta variant . Recent data shows that one dose of the J& J vaccine is 81% effective against COVID-19-related hospitalizations and 79% effective against infection.
These results havent been published in a peer-reviewed journal they were announced in a J& J press release.
To read more about this announcement, click or tap here.
Kaiser Permanente Finds That Pfizer Vaccine Is Almost 90% Effective Against Covid
A recent Kaiser Permanente study found that the Pfizer COVID-19 vaccine is almost 90% effective at preventing infections 1 month after being fully vaccinated. The study took place between December 2020 and August 2021. It included almost 3.5 million people.
It also reported results for vaccine effectiveness against specific COVID-19 variants . After 1 month, the Pfizer vaccine was about 93% effective at preventing infections caused by the Delta variant within the health system. But after 4 months, it was estimated to be 53% effective.
Even though Pfizer vaccine protection may get lower over time, experts still consider it an effective vaccine. During the study, the vaccine was 93% effective against hospitalization from the Delta variant for up to 6 months.
However, declining vaccine protection has started the discussion around booster doses, including who needs them and when. Currently, booster shots are only recommended for special groups, like older adults or people with certain medical conditions.
What this means: You may be more likely to get sick after 4 months of being fully vaccinated with the Pfizer vaccine. But its still very effective at lowering your risk of ending up in the hospital.
What this doesnt mean: Everyone should get a booster shot right now. If youre not eligible quite yet for a booster shot, its important to wait for updated guidance on when to get it.
To read more about this study, click or tap here.
Don’t Miss: Cvs Rapid Testing Cost
How Are We Monitoring The Coronavirus Vaccines
Pfizer and Moderna have been monitoring immunity in people who were given their vaccines in the initial clinical trialsboth companies had reported strong overall efficacy at the six-month mark.
One thing researchers are monitoring in vaccine recipients is levels of antibodies, which are proteins produced by the bodys immune system when it detects harmful substances, and that are easily measured from blood samples. Antibodies are a really good marker for protection against infection, so we will be monitoring those levels for as long as we can measure them, says Akiko Iwasaki, PhD, a professor of immunobiology at Yale School of Medicine.
I tell my family, ‘It’s great that youre vaccinated… But even the vaccines dont have 100% guarantees, so… you want to keep weighing the risks,'” says Yale Medicine infectious diseases expert Jaimie Meyer, MD, MS
A report in The New England Journal of Medicine in April showed that 33 participants who had received the Moderna vaccine during the Phase I trial had a gradual decline in antibody protectionand, based on the slope, Iwasaki says, that is hopeful news. If antibodies are going down very quickly, you would expect that to last for a short time. The slow decline raises hopes that the mRNA vaccines will be protective for at least a year, if not longer, she says.
This is a reason why the CDC recommends vaccinations for people who have had a COVID-19 infection as well as for those who have not.
How Do Vaccines Work
Vaccines help people develop immunity to a virus or other germ. A vaccine introduces a less harmful part of that germ or something created to look or behave like it into a persons body. The bodys immune system develops antibodies that fight that particular germ and keep the person from getting sick from it. Later, if the person encounters that germ again, their immune system can recognize it and remember how to fight it off.
Recommended Reading: How Long Cvs Rapid Test
Omicron: Three Vaccine Doses Key For Protection Against Variant
Two doses of a Covid vaccine are not enough to stop you catching the Omicron variant, UK scientists have warned.
Early analysis of UK Omicron and Delta cases showed the vaccines were less effective at stopping the new variant.
But a third booster prevents around 75% of people getting any Covid symptoms.
Meanwhile, Levelling Up Secretary Michael Gove, who chaired a meeting with first ministers of the devolved nations this afternoon, warned the UK faces a “deeply concerning situation”.
Speaking after the meeting of the government’s emergency committee Cobra, he said measures taken so far were “proportionate”, but ministers were “absolutely” keeping everything under review.
“Action is absolutely required, and as new data comes in we will consider what action we do require to take in the face of that data,” he added.
It comes as another 448 cases of Omicron were confirmed in the UK, taking the number reported so far to 1,265. The total number of Covid cases recorded on Friday was 58,194 – the highest figure since 9 January.
The government has said it is updating its guidance for care homes in England – limiting the number of visitors allowed per resident, and increasing testing “in order to balance the current Covid-19 risk”.
One of the main concerns since the heavily-mutated Omicron variant first emerged was that it would make vaccines less effective.
How Effective Is The Moderna Booster Vaccine
Vaccine creators have revealed their efforts will continue to develop an updated Omicron-based vaccine by Spring, 2022.
For now, the pharmaceutical company says the Moderna booster is proving effective at increasing the level of antibodies against the newest strain of COVID-19.
Dr Paul Burton, Modernas chief medical officer, told The Guardian: What we have available right now is 1273.Its highly effective and extremely safe.
“I think it will protect people through the coming holiday period and through these winter months, when were going to see the most severe pressure of Omicron.
Recommended Reading: How Much Is A Rapid Test At Cvs