AstraZeneca vaccine: The key questions about Vaxzevria

Vaxzevria  is the name of the corona vaccine that AstraZeneca developed together with Oxford University. The vector vaccine is considered effective and safe – but it made numerous negative headlines. Many people are now unsure and cancel their vaccination appointments, others still want to be vaccinated with the vaccine.

Vaxzevria or not? The decision is not easy for many because they have questions: First, older people should not be vaccinated with the vaccine, now it is no longer recommended for younger people – why? How high is the risk of thrombosis really and can the vaccination interval be shortened? Why should the second vaccination be done with an  mRNA vaccine  ? The following photo series answers these and other questions about the AstraZeneca vaccine.

In addition,  in this article you will find detailed information about the vaccine, its effectiveness and possible side effects .

First for young people, then for older people – why has the recommendation changed?

When the decision on the approval of the AstraZeneca vaccine in the EU was made in January 2021, there was even less data on the vaccine than today. However, the European Medicines Agency (EMA) judged the data to be sufficient and approved the vaccine for all people aged 18 and over.

In Germany, the Standing Vaccination Commission (STIKO) makes recommendations on the use of vaccines – it may come to different assessments than the EMA. The STIKO initially assessed the data situation for people over 65 as insufficient and therefore initially only recommended the vaccine for people under 65 years of age. Subsequent studies closed the gap in the data, which is why the STIKO recommended the vaccine in March for people aged 65 and over.

Then, however, reports of rare sinus vein thrombosis led to a temporary suspension of vaccination. The vaccinations were resumed shortly thereafter after an examination by the EMA. However, on April 1, the STIKO recommended that the vaccine should only be used from the age of 60, since the risk of the rare side effect of everything seems to be increased in younger people. Younger people can still be vaccinated with it at their own request and after consulting a doctor.

Thrombosis as a side effect: how high is the risk?

In some cases, so-called sinus vein thrombosis (cerebral vein thrombosis) was observed four to 16 days after the vaccination – often in connection with a lack of  blood platelets  ( thrombocytopenia ). In some cases, there were even fatalities as a result. It is now known how to   recognize and treat this rare form of thrombosis .

According to the EMA, the side effect occurs in one in 100,000 people who are vaccinated – this corresponds to 0.001 percent. In older people in particular, the risk of a severe course of  COVID-19  is much higher in comparison. According to the EMA, the benefit of the vaccine therefore outweighs the risk. However , if the risk of contracting the  coronavirus  is very low (e.g. with a very low incidence), then the benefit does not outweigh it – according to the EMA, people between the ages of 20 and 49 should then consider not vaccinating with this vaccine for the time being .

So far, no clear factors have been identified that could be used to determine the risk of developing cerebral vein thrombosis after vaccination with Vaxzevria. It is still unclear whether, for example, the birth control pill, smoking, previous thrombosis or a genetic predisposition increase the risk of this rare side effect.

Possible symptoms of sinus venous thrombosis include   dizziness, severe headaches, blurred vision or punctate skin bleeding (petechiae).

What other side effects can occur?

After vaccination against COVID-19, so-called vaccination reactions can occur, which usually disappear by themselves after a few days. This includes:

• pain at the injection site
• tiredness and exhaustion
• headache
• malaise
• chills and  chills
• fever or high temperature
• muscle and  limb pain
• nausea

These vaccination reactions are usually more severe with the first vaccination than with the second vaccination. Younger people reported vaccination reactions more frequently than older people. If the symptoms do not subside after several days or even worsen, you should seek medical advice.

In addition, extremely rare side effects may occur. In addition to the cerebral vein thrombosis already mentioned, this also includes other forms of thrombosis (e.g. pulmonary embolism). Clarkson’s syndrome (capillary leak syndrome) , in which the capillaries become too permeable, could also  be a possible, very rare consequence, especially if there is a corresponding medical history.

Guillain-Barré syndrome, a nerve disease, is also one of the very rare side effects. Transverse myelitis can also occur as a result of vaccination. In the rare neurological disease, inflammation of the spinal cord causes symptoms such as abnormal sensations (tingling, numbness, pain, etc.), weakness in the arms and legs, or impaired bladder or bowel function.

Should the interval between the first and second vaccination be shortened?

According to the approval, the interval between the first and second vaccination for Vaxzevria can be four to twelve weeks. Many people prefer an early second appointment in order to receive full vaccination protection as quickly as possible. However, most experts advise against shortening the distance and recommend using the maximum distance instead. Because study data indicate that the effectiveness of the vaccination increases when the two doses are twelve weeks apart. Then the effectiveness of the vaccine could be up to 81 percent. The Standing Vaccination Committee recommends an  interval of nine to twelve weeks  if both vaccinations are carried out with Vaxzevria.

If the first vaccination is carried out with the AstraZeneca vaccine and the second vaccination with an mRNA vaccine, the interval should be  at least four weeks according to the recommendation of the Standing Committee on Vaccination  . Studies also suggest that the immediate  vaccination reactions , i.e. symptoms that occur shortly after the vaccination, could be less pronounced with a longer interval than with an interval of only four weeks.

Second vaccination with an mRNA vaccine – what are the consequences?

Before STIKO changed its recommendation in April 2021 to preferably use the vaccine in people over the age of 60, numerous younger people had already been vaccinated with the vaccine. These people were recommended to take the second vaccination at an interval of nine to twelve weeks with an mRNA vaccine, i.e. the vaccines from BioNtech/Pfizer or  Moderna . In July, the Standing Committee on Vaccination recommended that all people, regardless of age, who received a primary vaccination with Vaxzevria should receive a second vaccination with an mRNA vaccine.

Experts consider this combination, also known as a heterologous vaccination scheme or cross-vaccination, to be safe and even particularly effective. Study data show that vaccinated people subsequently have more antibodies than people who have been vaccinated twice with the same vaccine. It can be assumed that they are better protected against the corona virus, especially against the Delta variant. Further investigations into the effects are still ongoing.

For the booster vaccination (third vaccination), only mRNA vaccines are currently recommended.

Does the AstraZeneca vaccine protect against the virus mutations?

In principle, the vaccine also protects against virus mutations. However, there may be differences depending on the type of mutation:

•  The vaccine provides good protection (60 percent) against the Alpha variant  (B.1.1.7) that is widespread in Great Britain.
• In the case of the beta variant (B.1.351) , which is rampant in South Africa   , the vaccination protection is considered to be significantly reduced in relation to mild and moderate courses of the disease – the effect is given here at around ten to 20 percent.
• The vaccine is also said to be somewhat less effective against the gamma (P.1) variant discovered in Brazil   , but still offers good protection.
• For protection against the Indian variant  Delta (B.1.617.2)  , an effectiveness of 60 percent is given.

With regard to the  omicron variant  , initial study results indicate that the vaccination protection is significantly reduced after a double vaccination. A booster with an mRNA vaccine significantly improves immunization protection. Additional data also suggest that a booster dose of AstraZeneca’s vaccine (regardless of which vaccine was used for the two previous doses) restores immunization protection to the level of the second dose.