Do I need a second jab of the AstraZeneca vaccine?
Yes. For more effective protection against COVID-19, a second jab is needed. The second dose also ensures that you are protected for longer than after only one jab, and also have more effective protection against variants of the virus.
I want a second jab of a different vaccine. Is that possible?
Yes, that is possible. People who have received a first vaccination with the AstraZeneca vaccine may choose the Pfizer vaccine for their second vaccination. Following the advisory opinion issued by the Health Council, the Minister of Health, Welfare and Sport announced that decision. No results are available yet from studies involving other combinations, for example with the Moderna vaccine.
- Exception:People who received a first vaccination with AstraZeneca and then experienced a severe allergic reaction, or the very rare side-effect of blood clots with lower platelets (thrombosis with thrombocytopenia syndrome or TTS), are advised not to get a second vaccination, not even with a different type of vaccine. People who experienced some other serious side-effect after their first vaccination with AstraZeneca should consult their treating physician for advice.
How effective is the protection offered by the combination of these two different vaccines?
Various studies have shown that the combination of a first vaccination with AstraZeneca and a second vaccination with Pfizer/BioNTech offers the same effective protection against serious illness as two doses of the AstraZeneca vaccine.
What is known about the safety of combining the AstraZeneca and Pfizer vaccines?
So far, there is no evidence that more serious side-effects occur after the combination of AstraZeneca and Pfizer than after vaccination with two doses of AstraZeneca, or two doses of Pfizer. However, more people reported fever, tiredness, chills, headaches and muscle aches after the combination of the vaccines than after vaccination with two doses of AstraZeneca. However, these symptoms disappeared within a few days.
After the first vaccination with AstraZeneca, I had a severe side-effect or allergic reaction. Can I receive the Pfizer vaccine for my second vaccination?
No. If you received a first vaccination with AstraZeneca and then experienced a severe allergic reaction, or the very rare side-effect of blood clots with lower platelets (thrombosis with thrombocytopenia syndrome or TTS), you are advised not to get a second vaccination, not even with a different type of vaccine. If you experienced some other serious side-effect after your first vaccination with AstraZeneca, you can consult your treating physician for advice.
What is known about a serious side-effect after vaccination with AstraZeneca?
By the beginning of April, the Pharmacovigilance Centre Lareb had received eight reports of a rare and serious combination of symptoms after vaccination with the AstraZeneca vaccine. It involves a combination of blood clots with low levels of blood platelets. The symptoms appeared 7 to 20 days after vaccination. The cases involved women between the ages of 23 and 65 years. The European Medicines Agency (EMA) has concluded, based on all available data, that there is a possible link between the vaccine and this very rare but serious combination of symptoms, but it is very unlikely to occur.
Why are AstraZeneca vaccinations continuing for people born in 1960 or before?
The Health Council of the Netherlands advises continuing to use the AstraZeneca vaccine for people aged 60 and over (born in 1960 or before). The risk of serious consequences from COVID-19 is much higher than the risk of this serious but rare combination of blood clots and low platelets after vaccination with the AstraZeneca vaccine. This is why these vaccinations will continue for people born in 1960 or before. People born in 1961 or later will receive a different vaccine.
Is it clear how this rare side-effect occurs?
Although the combination of blood clots (thrombosis) with low platelets (thrombocytopaenia) is serious, it is very rare. It is not yet clear exactly how this combination of symptoms occurs, but there is a theory that it may be caused by an immune response that has also been seen in patients who are being treated with heparin. The Dutch Society for Internal Medicine (NIV) and the Dutch Federation of Medical Specialists have notified the medical specialists in the Netherlands of this finding. They have also indicated which diagnostics and treatment should be considered if someone presents with this serious combination of symptoms after vaccination.
More information about the reported rare combination of symptoms can be found here: COVID-19 Vaccine AstraZeneca: benefits still outweigh the risks despite possible link to rare blood clots with low blood platelets | European Medicines Agency (europa.eu).
What should I do if I develop symptoms after vaccination?
After the vaccination, you may experience (common) side-effects within the first two days, such as sensitivity and pain at the injection site. Other common side-effects include muscle pain, as well as tiredness, elevated temperature and fever, cold chills, joint pain and nausea. These side-effects are common, but also disappear on their own after a few days.
Call your doctor or the out-of-hours medical centre if you experience the following symptoms after vaccination: shortness of breath, chest pain, swelling of the legs (puffy legs) or abdominal pain that lasts a long time.
Call your doctor or the out-of-hours medical centre immediately if you experience the following symptoms a few days after vaccination: severe or persistent headache, blurred vision, bruises or small round spots (petechia) on your skin in a different place than where you were injected with the vaccine.
You can report all suspected side-effects of the vaccination to the Pharmacovigilance Centre Lareb. Please especially report any side-effects that you found unusual, for example because the side-effect was not mentioned in the leaflet, or because the side-effect was different or more severe than you expected.
If I have had thrombosis or an embolism, do I have a higher risk of thrombosis as a result of vaccination with AstraZeneca?
No, we do not see higher rates of thrombosis or embolism after vaccination. People who have previously had thrombosis or an embolism do not have a higher risk of developing this rare combination of symptoms. This also applies to people who had thrombosis or an embolism due to COVID-19.
I have low blood platelets (thrombocytopaenia), am taking anticoagulant medication (blood thinners), or have a coagulation disorder (or a history of such disorders). Is there a higher risk that I will develop this serious combination of symptoms after vaccination with AstraZeneca?
No, there are no indications that you have a higher risk of developing this serious combination of symptoms after vaccination with AstraZeneca if you have low blood platelets, are taking anticoagulant medication, or have (or had) a coagulation disorder.
Is there a higher risk that I will develop this serious combination of symptoms if I am on the pill?
No, there is no evidence at this time that people who are on the pill (contraceptive medication) are more likely to develop this serious illness.
I have had heparin-induced thrombocytopaenia (HIT). Does this increase my risk if I am vaccinated with AstraZeneca?
HIT is a rare and very serious condition that occurs due to the administration of heparin. It is not yet known whether patients who have had HIT are at higher risk for the rare side-effect of the AstraZeneca vaccine. Patients who have had HIT should preferably contact their treating specialist, who will receive information from the appropriate medical and scientific bodies, in order to determine the best course of action for them.
More information
More information about vaccination with the AstraZeneca vaccine is available on the RIVM page about the COVID-19 vaccines.
Second dose of AstraZeneca vaccine after 4 to 12 weeks
The Health Council of the Netherlands has advised that the time between the first and second dose of the AstraZeneca vaccine can be between four and twelve weeks. It is not possible to specify the best interval within that range.
Why was the recommended interval for the second dose of AstraZeneca previously set at 12 weeks after the first dose?
In February, the Health Council advised giving the second dose 12 weeks after the first dose of AstraZeneca. That made it possible to offer protection against COVID-19 by giving a first dose to as many people as possible, as quickly as possible, while managing limited vaccine supplies.
Why does the Health Council advise an interval of 4 to 12 weeks between the first and second dose of the AstraZeneca vaccine?
The AstraZeneca vaccine is 60-80% effective in preventing disease caused by the coronavirus SARS-CoV-2. This means that in a group of vaccinated people, there will be 60-80% fewer people who get COVID-19 symptoms than in a group (of the same size) of unvaccinated people.
A number of studies on the AstraZeneca vaccine showed a trend that a longer interval between two doses provides better protection: if the second vaccination is administered after 12 or more weeks, it offers better protection than an interval of less than 6 weeks. The Health Council notes that these studies do not offer sufficient evidence that a longer interval between the two vaccinations is in fact better.
The time between administering the first and second dose of the AstraZeneca vaccine can be between four and twelve weeks. It is not possible to specify the best interval within that range. This corresponds to the manufacturer’s recommendations.
What interval is now being used between two vaccinations?
The aim is to give the second vaccination between 4 and 12 weeks after the first. If that is not possible for practical reasons, it is not a problem to extend the interval to 14 weeks. It is mainly important that the second vaccination is administered.
Are people who had an interval of 12 weeks between the first and second vaccination now protected less effectively?
No, there is no reason to assume that an interval of 12 weeks or longer leads to less effective protection. Based on data on other vaccines, it is known that a longer interval between two vaccinations often leads to more effective protection after the second vaccination.
Does the advisory report of the Health Council also lead to changes in the interval between two AstraZeneca vaccinations in actual practice?
This also depends on other factors, such as the options for rescheduling appointments that have already been made, the actual vaccine deliveries, and the logistics of vaccine distribution. An interval of 6 to 14 weeks between two vaccinations is used in actual practice.