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COVID-19 vaccine: Your questions answered
From Department of Health
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From Department of Health
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Last updated on
On 11 March 2020, the World Health Organization (WHO) declared COVID-19 to be a pandemic. COVID-19 is impacting economies and societies all over the world. The measures in place in Ireland are part of our ongoing collective effort to reduce the spread of the virus here. This has been essential for our health. But it has also limited our ability to live our lives as we normally would.
Experience of COVID-19 varies from person-to-person. Some people experience very mild symptoms and may not even realise that they have COVID-19. Other people will become very ill and experience severe symptoms. This can lead to hospitalisation or a stay in an intensive care unit (ICU). Sadly, some people die from COVID-19 infection.
COVID-19 can have a devastating impact, especially on people who are the most vulnerable to the disease. This includes people who are over 70 years of age and people with underlying health conditions. For others who have experienced a milder form of the illness, we do not yet know what the long-term impact of the virus could be.
Widespread distribution of a COVID-19 vaccine will build up the levels of immunity against COVID-19 in the general population. It will reduce the chances of you and your family getting the virus.
Worldwide, they save at least 2-3 million lives each year – and many more from crippling and lifelong illnesses. Vaccination has eradicated diseases like smallpox and has minimised the impact of a range of other infectious diphtheria, polio, meningitis B and C and measles, mumps and rubella.
Ireland works within a EU system that regulates medicines and vaccines and makes sure they are safe and effective. No vaccine will be used in Ireland unless it is demonstrated to meet safety and effectiveness standards. All vaccines will be carefully monitored over time and safety data and information will be published and shared.
Traditionally, it has taken many years to develop a vaccine, confirm its safety and efficacy, and manufacture enough of it for public use. This timeline has been really cut down for COVID-19 vaccines though unprecedented scientific and medical research, investment and collaboration.
To date, the European Commission has authorised the use of the Pfizer/BioNTech, Moderna, AstraZeneca, Janssen and Novavax COVID-19 vaccines.
Vaccination is one of the most cost-effective health interventions available, saving millions of people from illness, disability and death each year. The World Health Organization (WHO) states a comprehensive vaccination programme is a cornerstone of good public health in any country.
Vaccination is a simple, very safe, and effective way of protecting people against harmful diseases before they come into contact with them. It uses your body’s natural defences to build resistance to specific infections and makes your immune system stronger.
Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications.
Most vaccines are given by an injection, but some are given orally (by mouth) or sprayed into the nose.
In Ireland today, vaccines are offered to children to protect against 13 diseases: diphtheria, haemophilus influenzae (Hib) type b, hepatitis B, HPV, measles, meningococcal disease (types A, B, C,W & Y), mumps, pertussis (whooping cough), pneumococcal, polio, rotavirus, rubella and tetanus. These diseases may result in serious complications including death. Outbreaks of these serious infectious diseases occur if children are not vaccinated.
Vaccines are a proven, cost-effective intervention to protect public health; second only to the provision of clean water.
Vaccinations are important to protect against Vaccine Preventable Diseases. They prime our immune systems to respond to pathogens which could otherwise cause infection or, as in the case of the Human Papilloma Virus (HPV), cancer.
Those who are not vaccinated are at a higher risk of developing infection if they are exposed to a vaccine preventable disease and, if they become infected, they are more likely to develop complications compared with those who have been vaccinated.
They also risk further passing their infection onto others. This includes people in the population who are unable to develop an immune response to fight infectious diseases and are at a high of serious complications and death, and infants who have not yet been fully vaccinated and are similarly are at risk of serious complications.
All vaccines used in Ireland are very safe. They are licenced by either the HPRA (Health Products Regulatory Authority) or the EMA (European Medicines Agency) only when they have been shown to be very safe and effective.
Licenced vaccines undergo thorough testing in multiple phases of trials before they are approved for use.
All medicines can cause side effects, however vaccine side effects are usually mild, like a sore arm or leg where the injection was given, or a slight fever. Serious side effects to vaccines are extremely rare.
Due to the urgency posed by the pandemic, unprecedented efforts are ongoing to develop and study COVID-19 vaccines in order to approve and make them available as soon as possible. What is different for COVID-19 vaccines is that speed of development and potential approval is much faster due to the public health emergency.
There are a number of critical factors that have all come together to help deliver very safe and effective vaccines at pace:
This is not the same as developing a vaccine 20, 30 years ago. We know so much more now. For example, the genetic sequence / the genetic building blocks of the virus were known in early January. Also applying the extensive knowledge on vaccine production gained with existing vaccines. Also, the development and technologies for some of the types of vaccines being used for COVID-19 had already started before the pandemic (such as during the SARS pandemic).
Vaccine development for COVID-19 vaccines is being fast-tracked globally. Development is compressed in time. Companies have used dedicated teams to simultaneously analyse results from earlier studies more quickly and map out next steps in terms of resources, funding and regulatory strategy. For example, combining clinical trial phases or conducting some studies in parallel where safe to do so. Companies are also expanding manufacturing capacity and have commenced, at their own risk, the manufacture process in advance of approval.
Due to the global emergency posed by the COVID-19 pandemic, an unprecedented level of investment has been channelled towards the development of potential COVID-19 vaccines in 2020. This investment has enabled potential vaccine developers, scientists, national governments and regulators to work in collaboration and to use well-established processes to ensure very safe and effective vaccines can reach the authorisation stage as quickly as possible.
Regulatory mechanisms enabling accelerated assessment, for example: early scientific advice, rolling review and expedited review of full market authorisation application (conditional marketing authorisation). Regulatory review happening in parallel with the development of the product. Regulators assessing data from the clinical trials as soon as they become available. Ireland, through the HPRA, is an active participant in all European reviews. The HPRA contributes directly to the assessment of all new medicines by the European Medicines Agency and the monitoring of their safety once in use.
But, COVID-19 vaccines will have to meet the exact same standards as any other vaccines. Rigorous and thorough review of all the data. People can be assured that COVID-19 vaccines can only be approved and used if they comply with all the requirements of quality, safety and efficacy.
Phase 3 clinical trials are the last phase of trials before a drug or vaccine can be taken to market. In order for a product to pass a Phase 3 clinical trial, it is required to be tested on large patient groups.
For example, the Pfizer/BioNTech Phase 3 Clinical trials involved over 43,000 participants. Normally, clinical trials can be held back due to low volunteer numbers and low disease prevalence – neither of which have been an issue in the case of COVID-19.
Vaccine effectiveness means how many vaccinated people end up being protected by the vaccine. As with all medicines, vaccines work in a way than has benefits and limitations – even working at their best they cannot protect from every possible case of disease.
The COVID-19 Vaccine Allocation Strategy prioritises groups based on (1) ethical principles and (2) profile of the disease, and takes account of COVID-19’s modes of transmission, the groups and individuals most susceptible to infection and what is currently known about the candidate vaccines. The Strategy will evolve and adapt as more detailed information on the vaccines and their safety and effectiveness becomes available.
The vaccine manufacturers will be obliged to provide ongoing data on the performance and safety of the vaccine over the long term.
The HPRA has also put in place plans and resources to support effective monitoring in Ireland to track safety. The HPRA will work closely with colleagues across the national, European and global networks in this regard.
When someone is vaccinated, they are very likely to be protected against the targeted disease. But not every vaccinated person becomes protected, and not everyone can be vaccinated. People with underlying health conditions that weaken their immune systems (such as cancer or HIV) or who have severe allergies to some vaccine components may not be able to get vaccinated with certain vaccines.
These people can still be protected if they live among others who are vaccinated. When a lot of people in a community are vaccinated the virus has a hard time circulating because most of the people it encounters are immune.
The more that others are vaccinated, the less likely people who are unable to be protected by vaccines are at risk of even being exposed to the virus. This is called herd immunity.
This is especially important for those people who not only can’t be vaccinated but may be more susceptible to the diseases we vaccinate against. No single vaccine provides 100% protection, and herd immunity does not provide full protection to those who cannot safely be vaccinated. But with herd immunity, these people will have substantial protection, thanks to those around them being vaccinated.
Vaccinating not only protects yourself, but also protects those in the community who are unable to be vaccinated. If you are able to, get vaccinated.
Wearing a face mask not only helps protect you, but also prevents people who do not know they have COVID-19 from spreading it to others.
Face masks are mandatory in retail outlets, banks, credit unions and post offices, in taxis, in bus and rail stations, on public transport and for workers in customer facing roles in cafés, bars and restaurants.
Vaccines are very safe. Most vaccine adverse events are minor and temporary, such as a sore arm or mild fever. These can often be controlled by taking paracetamol after vaccination.
More serious adverse events occur rarely (on the order of one per thousands to one per millions of doses).
Once vaccines are authorised for use, a monitoring phase continues for as long as the vaccine is being used in the community and can pick up on rare or very rare side effects that may not have been seen in clinical trials.
In all our vaccination programmes, we recommend that people should get information on the vaccine and the illness it prevents from trusted sources. People report that the sources of health information they trust include their GP, their pharmacist, nurses and other health professionals, the Department of Health, the HSE and health experts.
People can find factual, up-to-date information based on scientific evidence on www.gov.ie, www.hse.ie and www.hpra.ie.
Patient information leaflets are available for download and printing from the European Medicines Agency (EMA).
You can read information about the following vaccines on the EMA website:
You can also get COVID-19 updates from the Health Products Regulatory Authority (HPRA).
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