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Updated on July 1, 2022 2:32 pm
All countries
Updated on July 1, 2022 2:32 pm
All countries
Updated on July 1, 2022 2:32 pm

Global Statistics

All countries
Updated on July 1, 2022 2:32 pm
All countries
Updated on July 1, 2022 2:32 pm
All countries
Updated on July 1, 2022 2:32 pm
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How The Covid Vaccine Works

What Are The Differences Between The Two

How does Moderna’s Coronavirus vaccine work?

These two COVID-19 vaccines are very similar. The main differences come in to play in relation to transporting and handling the vaccines. The Pfizer vaccine must be stored at -94° Fahrenheit. The Moderna vaccine needs to be stored at -4° Fahrenheit.

Both teach your immune system to destroy the coronavirus. Both use messenger RNA to instruct your body to build the spike proteins that are on the SARS-CoV-2 virus. Then your immune system kills it and remembers the protein so your body is ready if you’re infected with COVID-19.

Both are very safe and very effective. The Pfizer vaccine is 95% effective against COVID-19, and Modernas vaccine is 94.1% effective. They have similar temporary side effects, and those reactions are stronger after the second shot for both.

There are two differences that impact the public:

  • Pfizers vaccine is authorized for people ages 12 and older. Modernas is authorized for people ages 18 and older.
  • The two Pfizer doses are given 21 days apart. The two Moderna doses are given 28 days apart.

How We Know That The Covid

We keep hearing that the COVID-19 vaccines work but some people have asked us, How do we know that they work?

Luckily, we have a growing trove of data that show that these vaccines are indeed effective against catching the virus, transmitting it to other people, and ending up in the hospital because of it.

Efficacy in clinical trials

First, there was the experimental work done as the vaccines were developed and tested in both animal models and in human participants. Large clinical trials were eventually conducted where some participants were randomly assigned to receive the vaccine while others were given a placebo injection. These participants were followed over three months to see how many in each group would go on to get COVID-19. This extensive testing revealed the efficacy of these vaccines, meaning how good they were at preventing infection by the SARS-CoV-2 coronavirus under the ideal and controlled circumstances of a clinical trial.

Modernas mRNA vaccine performed similarly well, with an efficacy of 94.1%. AstraZeneca/COVISHIELDs vaccine, which uses a harmless virus to deliver the DNA to make the coronavirus spike protein, was said to have an efficacy of 76% at reducing the risk of symptomatic COVID-19. Finally, the Janssen vaccine, which works similarly to AstraZenecas, reported an efficacy of 66% at preventing symptomatic COVID-19.

Effectiveness in the real world

Limitations to this body of evidence

Prompting An Immune Response

Because the coronaviruses in CoronaVac are dead, they can be injected into the arm without causing Covid-19. Once inside the body, some of the inactivated viruses are swallowed up by a type of immune cell called an antigen-presenting cell.




The antigen-presenting cell tears the coronavirus apart and displays some of its fragments on its surface. A so-called helper T cell may detect the fragment. If the fragment fits into one of its surface proteins, the T cell becomes activated and can help recruit other immune cells to respond to the vaccine.

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Once I’ve Been Vaccinated How Long Does It Take For Covid

This is not entirely clear. Data released by the U.S. Food and Drug Administration show that COVID-19 protection from the Pfizer/BioNTech vaccine was demonstrated in the clinical trials at about 14 days after the first shot. The FDA said some level of immunity may start sooner, but how much is not certain.

The trials also confirmed that the vaccine was 95% effective against COVID-19 seven to 14 days after the second dose.

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A soldier administers a vaccination at the Army Reserve Centre in Poole, England.

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Immunity offered by vaccines wanes more quickly with omicron, finds UK study

The protection conferred by booster vaccines against the omicron variant begins to wane within 10 weeks, according to a briefing released by the UK Health Security Agency .

Based on an analysis of 147,597 delta and 68,489 omicron cases, the agency found that the Oxford/AstraZeneca, Pfizer/BioNTech and Moderna vaccines are less effective against omicron than delta. For people who had two initial doses of the Oxford/AstraZeneca vaccine, the UKHSA estimates that Pfizer/BioNTech or Moderna boosters are around 60 per cent effective at preventing symptomatic infections from omicron 2 to 4 weeks after the third dose, but this falls to 35 to 45 per cent by 10 weeks. For those who had two initial doses of Pfizer/BioNTech, protection falls from 70 per cent at 2 to 4 weeks to 45 per cent at 10 weeks after a Pfizer booster, but stays around 70 to 75 per cent up to 9 weeks after a Moderna booster.

However, modelling suggests that the severity of omicron would need to be around 90 per cent lower to avoid similar levels of hospital admissions to previous waves, according to minutes from a meeting of the UK governments Scientific Advisory Group for Emergencies on Monday.

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Does It Lead To More Severe Disease

It has been suggested that although omicron is more transmissible than delta, it causes less severe disease. Occupancy of intensive care beds in South African hospitals between 14 November and 4 December was 6.3%, which the World Health Organization said was very low compared with the same period when the country was facing the peak linked to the delta variant in July.

Further data from one of the worst affected health districts in South Africa showed that, over the same time period, 98 of 1200 people admitted to hospital were receiving supplemental oxygen and four were being ventilated. This is very preliminary data with a small sample size, and most of the people admitted to the health facilities were under the age of 40. As the clinical profile of patients changes, the impact of omicron may change, WHO said.5

Speaking at a German Science Media Centre briefing on 8 December, Florian Krammer, professor of vaccinology at Mount Sinai Hospital in New York, said, We can only speculate about this. We have to be very careful here, because were talking about a young population that has a very high baseline immunity from previous infection, and thats why we may be seeing a little bit of a milder disease. What we need to assume is that omicron will be very similar to the other variants in terms of severity.

Effectiveness Against New Strains

The COVID-19 virus has changed over time due to mutations that result in a different strain of the virus. This is common for viruses, but some changes have greater impact than others. They may spread more rapidly, cause more or less serious illness, or fail to respond to the existing vaccines.

The CDC will classify some strains as a “variant of concern” when they have the potential for this greater impact. As of December 2021, there were two variants of concern in the U.S. They were:

  • Omicron first identified in Botswana and South Africa
  • Delta first identified in India

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How The Vaccines Work

All vaccines contain ingredients that help your immune system make antibodies .

If you get a vaccination and then come into contact with the bacteria or virus that causes the disease, your immune system will recognise it and be able to protect you by producing the right antibodies.

Coronavirus vaccination offers good protection within 3 to 4 weeks of the first dose.

Having all the recommended doses of the vaccine is important for longer-term protection against coronavirus.

The Four Main Types Of Covid

How the COVID-19 vaccine works

There are four categories of vaccines in clinical trials: whole virus, protein subunit, viral vector and nucleic acid . Some of them try to smuggle the antigen into the body, others use the bodys own cells to make the viral antigen.

Whole virus

Many conventional vaccines use whole viruses to trigger an immune response. There are two main approaches. Live attenuated vaccines use a weakened form of the virus that can still replicate without causing illness. Inactivated vaccines use viruses whose genetic material has been destroyed so they cannot replicate, but can still trigger an immune response. Both types use well-established technology and pathways for regulatory approval, but live attenuated ones may risk causing disease in people with weak immune systems and often require careful cold storage, making their use more challenging in low-resource countries. Inactivated virus vaccines can be given to people with compromised immune systems but might also need cold storage.

Protein subunit

Subunit vaccines use pieces of the pathogen – often fragments of protein – to trigger an immune response. Doing so minimises the risk of side effects, but it also means the immune response may be weaker. This is why they often require adjuvants, to help boost the immune response. An example of an existing subunit vaccine is the hepatitis B vaccine.

Nucleic acid

Viral vector

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How Do The Vaccines Work

  • There are three main types of COVID-19 vaccines: messenger RNA , protein subunit and vector.
  • All three vaccine types either deliver, or cause our bodies to make, harmless proteins like the ones found on the surface of the COVID-19 virus.
  • The vaccine teaches our immune system to recognize the virus. After we are vaccinated, if we are exposed to the virus, our immune system recognizes, attacks and blocks the virus.

There Are Four Types Of Covid

The fight against COVID-19 has seen vaccine development move at record speed, with more than 170 different vaccines in trials. But how are they different from each other and how will they protect us against the disease?

There are more vaccine candidates simultaneously in the pipeline for COVID-19 than ever before for an infectious disease. All of them are trying to achieve the same thing immunity to the virus, and some might also be able to stop transmission. They do so by stimulating an immune response to an antigen, a molecule found on the virus. In the case of COVID-19, the antigen is typically the characteristic spike protein found on the surface of the virus, which it normally uses to help it invade human cells.

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What Are Countries Doing In Response

Many countries have implemented travel bans or tighter restrictions on travellers from some African countries. The UK, where more than 800 cases of omicron have been detected so far, has placed 11 African countries on its red list: Angola, Botswana, Eswatini , Lesotho, Malawi, Mozambique, Namibia, Nigeria, South Africa, Zambia, and Zimbabwe. This has raised questions regarding why African countries are facing these measures when the variant is circulating in many European countries as well.14

Alongside travel restrictions, the UK has also put some additional domestic measures in place, including recommending that people work from home where possible and wearing face masks in many indoor public places, such as cinemas and theatres.15 Some other European countries, including Austria and Germany, already had some form of regional or national lockdown in place before the variant was widely reported. It is unclear how omicron will affect the lifting of these restrictions.

This article is made freely available for use in accordance with BMJ’s website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose provided that all copyright notices and trade marks are retained.

Most People Need Booster Shots

Why you

While COVID-19 vaccines are effective, studies have shown some declines in vaccine effectiveness against infections over time, especially when the Delta variant was circulating widely. Everyone ages 18 and older should get a booster shot either 6 months after their initial Pfizer or Moderna series, or 2 months after their initial Johnson & Johnsons Janssen vaccine. People ages 1617 may get a booster dose of Pfizer at least 6 months after their initial series of vaccines.

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Q: Is It An Mrna Vaccine How Does It Work

A: The Novavax vaccine is a protein-based, or protein-subunit, vaccine. It is not an mRNA vaccine.

mRNA vaccines use material from the virus to teach the body’s cells to make copies of a protein unique to the virus, and in this manner build up resistance to it.

On the other hand, protein-based vaccines include pieces of the virus, but not the entire germ. When a person is vaccinated with them, their body realises that the protein should not be there and creates antibodies to fight it.

The Novavax vaccine teaches the body’s immune system to create antibodies that fight the coronavirus’ spike protein, which it uses to enter human cells.

In order to make the protein, scientists took a modified spike gene and put it into an insect virus.

The virus was allowed to infect moth cells and, when it did, the infected cells created many spike proteins.

These spike proteins were then harvested, purified, and put into nanoparticles. The nanoparticles were combined with an extract from the soapbark tree, which helps boost the immune system’s response.

When the vaccine is injected into a person, the body’s immune system will encounter the nanoparticles and in doing so, learn how to fight the virus.

Can I Get My First Covid

The CDC recommends that when the same mRNA vaccine is unavailable, it’s preferred that you delay your second dose to receive the same product. However, you can receive a second dose in your series of a different mRNA COVID-19 vaccine. If you receive vaccines from two different manufacturers, your vaccine series is considered complete.

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Is It Common To Have A Stronger Reaction After The Second Covid

It is normal to have a stronger reaction after the second dose because that’s when your immune system really kicks into gear. That big immune response is what causes the stronger reaction. It’s called a boosting phenomenon, and it builds an even greater ability to defeat COVID-19. Here’s how it works:

When you get the first dose, your body learns to make antibodies to fight COVID-19. Then you get the second vaccine, and you already have the antibodies ready to go, so that shot kicks them into action. That more robust immune response accounts for the stronger reactions. Those reactions tell you the vaccine is working.

Although stronger reactions after the second dose are common, experts say some people may have little or no reaction.

To help with the stronger side effects, it’s OK to take Tylenol or other over-the-counter pain relievers after your shot but not before to help ease discomfort. As always, you will want to consult with your physician.

Can Pcr Testing Detect Omicron

WATCH: How the Johnson & Johnson COVID-19 vaccine works

Current PCR testing does detect the variant, although several laboratories have said that one widely used test doesnt detect one of the three target genes . This is the same gene dropout that was seen with the alpha variant in late 2020.13 WHO has said that this dropout can be used as a marker for the omicron variant, pending sequencing confirmation.2

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Bmc Updates And Information

Our Emergency Department is experiencing exceptionally long wait times and is very busy at this time. Please do not come to the Emergency Department for a COVID-19 test, unless you need emergency care. If you received a positive result using an at-home test, you do not need to get a PCR test for confirmation. You can also .

Should I Still Get A Vaccine If I Already Had Covid

Experts recommend getting the vaccine even if youve had COVID-19. There isnt enough information to say if you have natural immunity from being sick or how long it may last, according to the CDC. Experts recommend waiting at least until you’ve recovered from acute illness and no longer have to isolate . They also suggest waiting about 90 days after you’ve recovered from COVID-19 . The waiting period can help keep your reactions to the COVID-19 vaccine more mild.

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How Long Will Immunity Last

According to Pfizer, initial results based on Phase 3 clinical trials in adults found the vaccine was:

  • 100% effective in preventing severe disease
  • 95% effective in preventing severe disease
  • 91% effective in providing immunity against COVID-19 for six months

A November 2021 update focused on how effective the vaccine was in people ages 12 to 15. These results showed the vaccine was 100% effective against COVID-19.

Further research on the Pfizer vaccine, also known as Comirnaty, supports its effectiveness. A November 2021 research review of studies on nine different COVID-19 vaccines developed around the world found that overall, the Pfizer and Moderna vaccines performed better than alternatives in preventing symptomatic disease.

What Do South Africa Lab Tests Tell Us About Omicron

What to know about COVID

Some drop-off is not surprising.

The amount seen in this small study is in the ballpark of what scientists were expecting given the substantial mutations that Omicron has compared with original Covid that the vaccines were designed to fight.

What these early lab results still can’t tell us is what it truly means in terms of how well existing vaccines work in protecting people around the globe.

Neutralising antibodies – which latch on to the virus to stop it infecting our cells – are just one part of the immune response to Covid.

Jabs, or past infection, also trigger T cells that help protect us against the virus.

The picture will become clearer in the coming weeks as we gather more data from around the world on how many people are catching Omicron, how sick they are getting and whether they were vaccinated or not.

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