How Do Vaccines Actually Work
Vaccines prevent millions of deaths every year by harnessing the bodys immune system to create defences against future infection. But how exactly does this work?
Vaccines are a proven way of preventing disease. Through vaccination programmes we have managed to eradicate smallpox and are within reach of doing the same against polio. But how do vaccines work?
How Is The Flu Shot Made
Tran: Vaccine developers use three different types of processes to make flu shots.
Currently, most influenza vaccines are made using an egg-based process. Manufacturers use a fertilized chicken egg to grow whichever four strains of the virus the U.S. Food and Drug Administration decides will be dominant during the upcoming flu season. Manufacturers incubate the egg, allowing the virus to replicate, harvest the virus and then deactivate or weaken it before adding it to a mass-produced injection. A second method uses an animal cell instead of egg cells.
The third process isolates the genes that have the instructions for making the target protein that your body’s immune system must identify. Those genes are combined with a different virus that infects invertebrates, such as worms and helps pass the genetic instructions to a host cell. These proteins are grown in bulk, purified and become so-called recombinant vaccines.
How Vaccines Are Approved
The Therapeutic Goods Administration approves vaccines for use in Australia after a careful evaluation process.
The COVID-19 vaccines have provisional approval. This means they can be legally used in Australia because the need for early access outweighs the risks. The manufacturers continue to collect data on vaccine safety and efficacy and will apply for full approval later.
The TGA also continuously monitors vaccine safety and side effects.
Don’t Miss: Does Medica Cover Shingles Vaccine
Myth: Natural Immunity Is Better Than A Vaccine
We still dont understand much about how long natural immunity to the coronavirus lasts. Overall, getting vaccinated is a safer way to build immunity, as getting COVID-19 can lead to:
- long COVID after your acute illness has passed
- severe illness that can include complications like respiratory distress or failure, blood clots, and organ damage
Vaccination is still important, even if youve already had COVID-19.
In fact, new research shows that people who have been vaccinated and have had COVID-19 have higher levels of neutralizing antibodies. This is called super immunity.
Celebrating Close Of Pneumococcal Amc With New Lower Price Of Us$ 200 Per Dose

Through the Pneumococcal Advance Market Commitment , which reached its conclusion on 31 December 2020, pneumococcal conjugate vaccines are available to Gavi countries at a new lower price of US$ 2.00 per dose, with the entry of the first vaccine from a Developing Countries Vaccine Manufacturers Network member, Serum Institute of India . The impact of this ten-year supply agreement is estimated to yield US$ 50100 million in additional savings for Gavi and Gavi countries.
Also Check: How To Give Kitten Vaccines
M Children Immunised In 2020
Countries immunised an additional 64 million children with Gavi support in 2020, often with more than one vaccine. Due to the impact of the COVID-19 pandemic, this represents a decrease from the 66 million children reached in 2019 but we exceeded our target of 300 million for the 20162020 period, helping countries immunise over 324 million unique children.
If I Already Had Covid
Yes. The Centers for Disease Control and Prevention recommends that people who have had Covid-19 should still be vaccinated because of the severe health risks associated with Covid-19 and the fact that reinfection is possible. People who were treated for Covid-19 with monoclonal antibodies or convalescent plasma should wait 90 days before getting a Covid-19 vaccine.
Recommended Reading: Should I Vaccinate My Child
Myths And Facts About Covid
Accurate vaccine information is critical and can help stop common myths and rumors. It can be difficult to know which sources of information you can trust. Learn more about finding credible vaccine information.
Below are myths and facts about COVID-19 vaccination.
Have more questions? Visit FAQs about Vaccination.
How The Vaccine Protects You
The vaccine contains messenger RNA made with the genetic code of spike proteins. When you’re injected with the vaccine, this messenger RNA enters your cells and produces a protein to stimulate an immune response, similar to COVID-19.
Now if you encounter the real virus, your body will recognize COVID-19 and is trained to fight it.
Recommended Reading: Why Is It Important To Get Vaccinated
Side Effects Of Bivalent Covid Vaccine
The Centers for Disease Control and Prevention of the United States has mentioned on its official website that there are some side effects of bivalent vaccines.
Similar to the primary series and other booster sorts of COVID vaccine, the probability of general side effects of bivalent COVID vaccine is going to be on a higher side as compared to severe side effects.
People who are allergic to any ingredient used in the bivalent COVID vaccine should not get it. At the same time, people who experience severe allergic reactions after taking the primary series of COVID vaccines should also avoid using a valid COVID vaccine also.
The Centers for Disease Control and prevention will leave you might experience below given side effects of the bivalent COVID vaccine, which will include:
There is also a probability that you can get severe side effects of the bivalent COVID vaccine, but the probability is going to be on the lowest side possible. The Bivalent COVID vaccine of Pfizer or Moderna is as safe as the primary series and its booster series.
What You Should Know About The New Omicron
The Food and Drug Administration recently approved new COVID-19 booster vaccines from Pfizer and Moderna. Each is designed to fight a pair of variants plaguing much of the United States and world for the past several months the BA.4 and BA.5 subvariants of the Omicron variant.
Here’s what you should know about the new boosters:
Recommended Reading: Is Yellow Fever Vaccination Required For Kenya
Dna Inside An Adenovirus
The researchers added the gene for the coronavirus spike protein to another virus called Adenovirus 26. Adenoviruses are common viruses that typically cause colds or flu-like symptoms. The Johnson & Johnson team used a modified adenovirus that can enter cells but cant replicate inside them or cause illness.
DNA inside
DNA inside
an adenovirus
Johnson & Johnsons vaccine comes out of decades of research on adenovirus-based vaccines. In July, the first one was approved for general use a vaccine for Ebola, also made by Johnson & Johnson. The company is also running trials on adenovirus-based vaccines for other diseases, including H.I.V. and Zika. Some other coronavirus vaccines are also based on adenoviruses, such as the one developed by the University of Oxford and AstraZeneca using a chimpanzee adenovirus.
Adenovirus-based vaccines for Covid-19 are more rugged than mRNA vaccines from Pfizer and Moderna. DNA is not as fragile as RNA, and the adenoviruss tough protein coat helps protect the genetic material inside. As a result, the Johnson & Johnson vaccine can be refrigerated for up to three months at 3646°F .
How Do Vaccines Help Our Immunity

Our immune system is like a library it stores information about every germ ever defeated. We sometimes call this immunological memory.Some antibodies remain on patrol in our bloodstream. So if we ever encounter the real germ in the future, our immune system can quickly trigger the memory cells and produce antibodies to defeat it. And this often occurs before we experience any symptoms of illness. Each vaccine is designed according to how the specific germs make us sick. For example, measles is the result of the bodys reaction to the whole virus and so the vaccine contains a weakened form of the virus. On the other hand, tetanus is caused by the bodys reaction to the toxin produced by the tetanus bacteria and so the vaccine contains inactivated tetanus toxin.
You May Like: How Much Does The Shingles Vaccine Cost At Walmart
Three Main Types Of Vaccines
-
mRNA
mRNA is a molecule that tells our bodies to make proteins. mRNA in the COVID-19 vaccine tells our cells to make harmless proteins just like those on the virus. The Pfizer and Moderna vaccines work this way.
-
Protein Subunit
Protein subunit vaccines, such as the Novavax vaccine, contain harmless pieces of proteins unique to the COVID-19 virus.
-
Vector
Vector vaccines, like the J& J vaccine, use another virus that has been made safe to deliver material that tells our cells to make harmless proteins unique to the COVID-19 virus.
When Are You Up To Date
You are up to date with your COVID-19 vaccines if you have completed a COVID-19 vaccine primary series and received the most recent booster dose recommended for you by CDC.
Vaccine recommendations are based on your age, the vaccine you first received, and time since last dose. People who are moderately or severely immunocompromised have different recommendations for COVID-19 vaccines.
Recommended Reading: Who Should Get Whooping Cough Vaccine
If We Didnt Have Vaccines Would Clean Water And Modern Hygiene Prevent These Diseases Anyway
No. Clean water and good personal, home, and public hygiene help slow down or stop some germs from spreading, but they dont get rid of diseases. Some diseases especially respiratory diseases that spread through the air, like measles are more difficult to prevent.
The bottom line is that as long as diseases are around, people will continue to get sick. And thats why its so important to get vaccinated. Learn more about getting vaccinated.
The Power Of Partnership
Gavis impact draws on the strengths of its core partners, the World Health Organization, UNICEF, the World Bank and the Bill & Melinda Gates Foundation, and plays a critical role in strengthening primary health care , bringing us closer to the Sustainable Development Goal of Universal Health Coverage , ensuring that no one is left behind.
Gavi also works with donors, including sovereign governments, private sector foundations and corporate partners NGOs, advocacy groups, professional and community associations, faith-based organisations and academia vaccine manufacturers, including those in emerging markets research and technical health institutes and implementing country governments.
Gavis impact draws on the strengths of its core partners, the World Health Organization, UNICEF, the World Bank and the Bill & Melinda Gates Foundation, and plays a critical role in strengthening primary health care , bringing us closer to the Sustainable Development Goal of Universal Health Coverage , ensuring that no one is left behind.
Gavi also works with donors, including sovereign governments, private sector foundations and corporate partners NGOs, advocacy groups, professional and community associations, faith-based organisations and academia vaccine manufacturers, including those in emerging markets research and technical health institutes and implementing country governments.
Bill Gates
Don’t Miss: What Vaccines Are You Given At Birth
How Do I Know Vaccines Are Safe
Before a vaccine can be given to the population it must go through rigorous testing. Like all medicines, vaccines go through many clinical trials, where they are administered and monitored in groups of volunteers. In the UK, the results of trials are then assessed by the Medicines and Healthcare products Regulatory Agency . Once licensed, the vaccine must then be further approved by the MHRA before it is added to the routine vaccination programme. Even once a vaccine becomes part of the vaccination programme, it is continually monitored for safety and effectiveness by the MHRA. Any suspected side effects are reported by medical providers or patients to the MHRA using the yellow card scheme. No medicine can ever be completely risk free or 100% effective. However, strong licensing processes and safety tests ensure that the health benefits of medicines being given through the NHS greatly outweigh any risks. As vaccines are given to healthy people, these regulatory measures are even stricter, meaning that the level of acceptable risk for vaccines is much lower than it would be for other medicines.9
How To Get The Bivalent Covid Vaccine In The Us
Similar to the primary series and booster series of COVID vaccine, the bivalent COVID vaccine is very easy to get in the United States.
The Centers for Disease Control and Prevention of the United States is in partnership with several pharmaceutical companies and independent clinics to vaccinate every American in the country.
You can easily create an appointment for Bible and COVID vaccines using the official website of any pharmaceutical giant such as Walgreens, Rite Aid, and CVS pharmacy. All these pharma giants are in partnership with the Centers for Disease Control and Prevention to provide free COVID vaccines.
You dont have to worry about the availability of bivalent COVID vaccine as the Center for Disease Control and Prevention has already made it pretty clear that we have enough supply of the vaccine, and it is available throughout the nation.
If you are not able to find any vaccination site near your neighborhood, then you can use the centralized database, which was launched by the CDC back in 2021.
- Kindly click on the above-given button to reach the centralized database of the COVID vaccine
- As soon as you reach the centralized database currently, enter your zip code, city name, or state name
- Your zip code or state name will help you find all the nearby vaccination sites.
- You can also filter out your results based on the vaccine you are looking for.
Don’t Miss: What Age Does A Child Get The Chickenpox Vaccine
Is It True That Getting Vaccinated Repeatedly Can Reduce Vaccine Effectiveness
A report examining studies from the 2010-2011 to the 2014-2015 seasons concluded that the effectiveness of a flu vaccine may be influenced by vaccination the prior season or during many prior seasons . In some seasons, protection against influenza A virus illness may have been lower for people vaccinated in the current season and the prior season compared with those who had only been vaccinated in the current season. This fits with findings on immune response to vaccination that suggest repeated influenza vaccination can weaken the immune response to vaccination and especially to the H3N2 vaccine component. However, repeated annual vaccination also can be beneficial during some seasons, since sometimes people retain and carry over immune protection from one season to the next. During some seasons, people who missed getting vaccinated still had residual protection against influenza illness.
When Were Flu Vaccines First Created And Approved For Use In The Us

Tran: The influenza virus was first isolated in people in the 1930s. The first flu vaccine was developed in the 1940s to support the U.S. Army during World War II because the flu was causing so much illness and death at that time. It wasn’t until 1945 that the first flu vaccine was licensed for use in civilians.
Read Also: How Much For Pneumonia Vaccine
Will I Be Protected After Just One Dose
While some protection may be conferred after a single dose of the Pfizer-BioNTech and Moderna mRNA vaccines, this protection is far less than after two doses. The second dose acts as a booster, better preparing the immune system to fight infection. All people should receive two doses of these vaccines.
The Vaccines Used To Protect Against Coronavirus
The coronavirus vaccine does not cause a coronavirus infection. It helps to build up your immunity to the virus, so your body will fight it off more easily if it affects you. The coronavirus vaccines do not contain a live virus. This can reduce your risk of developing coronavirus and make your symptoms milder if you do get it.
The safety and effectiveness of the coronavirus vaccines continues to be checked while in use.
Recommended Reading: Should Vaccinated People Avoid Unvaccinated People
Are The Vaccines Safe
The vaccine is deemed to be safe based upon a rigorous evaluation of currently available scientific evidence. If the available scientific evidence changes or if new information becomes available, the authorization for its use can be adapted.
The Pfizer vaccine study enrolled 43,538 participants, with 42% having diverse ethnic backgrounds. No serious safety concerns were observed. The only Grade 3 adverse events greater than or equal to 2% in frequency were fatigue and headache .
The Moderna vaccine study enrolled 30,000 participants, with 37% having diverse backgrounds. No serious safety concerns were observed. The majority of adverse events were mild or moderate in severity. Grade 3 events included injection site pain , fatigue , muscle pain or soreness , joint pain , headache , pain and redness at the injection site .
All vaccine trials have scheduled monitoring reviews, typically by an independent group known as a Data and Safety Monitoring Board, which routinely assesses safety or can be convened quickly to review any unanticipated adverse events.
Different Vaccines Work In Different Ways
The idea behind vaccines is to train up the immune system by showing it a version of a pathogen that wont harm the body, or just part of a pathogen containing antigens. This can trigger enough of an immune response to produce protective antibodies. There are four main types of vaccines, and they all work slightly differently.
Read Also: Is There A Vaccine For Aids
Ba5 Booster: Who Is The Biontech Vaccine Suitable For
A study published in the scientific journal
New England Journal of Medicine
helps to classify this .
This was carried out in Portugal, where the omicron variant BA.5 had spread comparatively early in Europe.
The result: An earlier vaccination plus a corona infection with BA.1 or BA.2 increases the protection against BA.5 enormously.