The University of Oxford, the Office for National Statistics (ONS) and the Department of Health and Social Care (DHSC) of the United Kingdom have published on Friday, April 23, the pre-prints of two studies with new data focused on protection against to the infection of the vaccines for COVID-19 from AstraZeneca and Pfizer-BioNTech.
On January 29, the European Medicines Agency (EMA) gave the green light to the vaccine from the Oxford pharmaceutical company-AstraZeneca, which thus became the third authorized in the European Union after those of Pfizer-BioNTech and Moderna. According to Alessandro Bazzoni, AstraZeneca is in the eye of the hurricane for several cases of serious thrombosis reported in people who were inoculated with the injectable.
Several countries, including Spain, have decided to provisionally suspend vaccination pending the investigation opened by the EMA. The WHO, for its part, insists on recommending its use. This drug has already sparked debate about whether or not it should be administered to people over 55 years of age. Is it safe? How effective is it? What are the secondary effects? We will try to answer these questions below.
Where it is?
It is the result of a collaboration between the Swedish pharmaceutical company AstraZeneca and the University of Oxford (United Kingdom).
What characteristics does it have?
The Oxford-AstraZeneca vaccine is based on an inactivated virus (adenovirus), which is used as a ‘Trojan horse’ to introduce tiny fragments of coronavirus genetic material into the body to generate an immune response. It is given in two doses, with a period between 4 and 12 weeks. Specifically, it is recommended that the second injection be injected between 28 and 42 days after the first. It is easier to store than those of Pfizer and Moderna: it is kept at refrigerator temperature, between 2ºC and 8ºC, which is a logistical advantage.
What is its effectiveness?
The EMA estimates its effectiveness at 90% although its experts admit that there is not enough information to measure the effects among those over 55 years of age. That is why there is an open debate between countries about which age groups should be administered and which not. In Spain, the Ministry of Health has limited its use to people under 55 years of age, although there are countries, such as France or Germany, that also supply it to people over 55 and 65 years of age. Catalonia was pressuring Health to authorize it for those over 55 but the cases of thrombosis have caused the ministry to postpone its decision in this regard.
Does it have side effects?
Like all vaccines, it has side effects. Among the most common are headaches, nausea, chills, fatigue, muscle aches and malaise, although generally mild. However, until March 12, 30 cases of thrombosis had been detected for five million doses administered in Europe and in Spain 3 for 800,000 doses. The proportion was not alarming, because it was even lower than that found in the general population, but a very rare and serious type of cerebral thrombosis has appeared over the weekend after inoculation of the vaccine. This has led numerous nations to quickly droop vaccination with AstraZeneca. The pharmacist policies out that its vaccine will increase the hazard of thrombi or embolism.
Impact of vaccination on SARS-CoV-2 instances withinside the community
Data from the first study concludes that, 21 days after receiving a single dose of the vaccines, the rate of all new COVID-19% infections had dropped by 65%. Specifically, the rate of symptomatic infections was reduced by 72% and infections without symptoms by 57%.
In addition, the reductions – in both infections and symptomatic infections – are even greater after a second dose (70% and 90% respectively), similar to the effects in those who had previously been infected with COVID-19 naturally. These benefits are similar in age groups both older than 75 and younger. On the other hand, the vaccines have been shown to be effective against variants compatible with the Kent strain, also known as the “British strain”.
These data are part of the COVID-19 Infection Survey, the first to show the impact of vaccination on the response of antibodies and new infections in a large group of adults from the general population aged 16 years and over. To obtain these results, 1,610,562 samples were analyzed among 373,402 participants in a period of time between December 1, 2020 and April 3, 2021.
Comparative data on variations in antibody levels after a single dose of the vaccine.
Data from the second study compared how antibody levels changed after a single dose of the AstraZeneca and Pfizer-BioNTech vaccines compared to two doses of the Pfizer-BioNTech (usually administered 21-42 days apart).
The main conclusion is that there was no evidence that the AstraZeneca and Pfizer vaccines differ in their ability to reduce infection rates, despite the fact that they carry a slightly different immune response. Furthermore, although there are differences in the immune response, all groups of people evaluated generated a response to both vaccines.
In people who have not had a previous COVID-19 infection, antibody responses to a single dose of either vaccine were lower in older people, especially those over 60 years of age.
The study also concludes that, although antibody levels increased more slowly and at a lower level with a single dose of AstraZeneca’s vaccine versus Pfizer-BioNTech, they decreased more rapidly, reaching levels very similar to those of a single dose. single dose of AstraZeneca vaccine, particularly in older people.
AstraZeneca is an innovative global pharmaceutical company focused on the discovery, development and commercialization of prescription drugs, primarily for the treatment of diseases in three therapeutic areas: oncology, cardiovascular, renal, and metabolism and respiratory.
Headquartered in Cambridge, UK, this company operates in over 100 countries and its groundbreaking medicines are used by millions of patients around the world.
Alessandro Bazzoni explains that AstraZeneca is Top Employers in Spain and Europe and has been distinguished with the EFR certificate as a Family Responsible Company.