AstraZeneca’s vaccine against COVID-19 has been at the center of controversy since the beginning of the year. In January, it was because of its manufacturing and distribution problems in the European Union that got it into a legal dispute with the bloc. But since March there has been talk of his possible relationship with a.
Despite this risk, which has caused several countries to restrict or cancel its application, the vaccine from the British Swedish laboratory is the only hope for many poor nations that depend on donations from the Covax mechanism or third countries.
This is what we know about this vaccine, designed in conjunction with the University of Oxford: its expected side effects, its relationship with clot formation, the doses that are necessary, and its distribution in Mexico.
What are the side effects of the AstraZeneca vaccine?
According to the European Medicines Agency (EMA), the AstraZeneca vaccine can have very common adverse reactions such as headache, nausea, muscle pain, joint pain, tenderness or pain at the injection site, itching in the area. injection, bruising at the injection site, fatigue, malaise, temperature rise up to 37 degrees and chills.
Other common side effects include a mild transient low platelet count, vomiting, diarrhea, swelling or redness at the injection site, and a fever greater than 38 degrees.
In clinical trials of the vaccine in the UK, Brazil and South Africa, most adverse reactions were found to be mild to moderate in intensity and resolved within days of vaccination. In addition, they explain that they are more intense after receiving the first dose than after receiving the second.
The AstraZeneca vaccine is given in two doses 8-12 weeks apart, according to the World Health Organization (WHO).
Serious side effects of this vaccine
Several countries in Europe, including Germany, France, Italy and Spain, suspended the use of the AstraZeneca vaccine in mid-March. The reason was the reports of several cases of blood problems in vaccinated people, such as the appearance of blood clots and clotting difficulties.
“This includes severe cases presenting as venous thrombosis, including unusual locations such as cerebral venous sinus thrombosis, splanchnic vein thrombosis, as well as arterial thrombosis (…). Some cases were fatal. Most of these cases they occurred within the first three weeks after vaccination and occurred mostly in women under 60 years of age, “says the EMA in a report on the vaccine.
After an analysis of the cases, the EMA concluded in April that there is a “possible link” between thrombi and the vaccine, but it always clarified that the benefits of vaccinating with AstraZeneca continue to outweigh its risks in all age groups, although some European countries have decided to limit its use only to those over 60 years of age.
In addition, he recommended giving the second dose of this vaccine to those who have already received the first without showing serious side effects because the second injection does not have more adverse effects than the first.
The European regulator recommended that health professionals be aware of the signs and symptoms of a thromboembolism or a low platelet count. Some of these are shortness of breath, chest pain, leg swelling, leg pain, persistent abdominal pain after vaccination.
Those who, after vaccination, develop neurological symptoms such as severe or persistent headaches, blurred vision, confusion or seizures, or who experience multiple small bruises on the skin at a different site than the injection should also seek immediate medical attention. of a few days.
“People diagnosed with thrombocytopenia (low platelet count) within three weeks of vaccination with Vaxzevria (AstraZeneca’s vaccine name in the EU) should be actively screened for signs of thrombosis. Likewise, people who present thrombosis within three weeks after vaccination should be evaluated for thrombocytopenia ”, according to the EMA.
The AstraZeneca vaccine in Mexico
The Federal Commission for the Protection against Sanitary Risks (Cofepris) of Mexico authorized and the University of Oxford on January 4, 2021.
The AstraZeneca vaccine belongs to the COVAX mechanism vaccine portfolio of the World Health Organization (WHO), with which Mexico could also access more doses of this drug through this route. Through this platform, vaccines were guaranteed for 20% of the population.
After the suspension of the use of the vaccine in Europe, the president of Mexico, Andrés Manuel López Obrador, in the country. “We have not had a problem with this vaccine, but at the moment it is reported not explaining well, but only for politicking purposes,” he said in one of his morning conferences.
On April 20, López Obrador himself received a first dose of the AstraZeneca vaccine and called on older adults to get vaccinated without fear.
Mexico has not only received vaccines from this manufacturer. In 2020, it was agreed with AstraZeneca and the University of Oxford, the developers of the formula, that Argentina would process the vaccines while Mexico would handle the packaging.
The project has been delayed for months, as it was expected that by March the first doses of the 150 million that AstraZeneca has committed to Latin America will begin to be distributed.
The government of Mexico reported on June 12 that it will send to Argentina the first 800,000 AstraZeneca anticovid vaccines that it produces in conjunction with that country, and announced that it has donated 400,000 doses to Belize, Bolivia and Paraguay.
On Sunday Mexico received a batch of AstraZeneca vaccines with 1.1 million doses that, added to the previous batches received, make a total of 12.9 million biologicals from this pharmaceutical company.
How effective is the AstraZeneca vaccine?
AstraZeneca’s COVID-19 vaccine is 63.09% effective against symptomatic SASR-CoV-2 infection, according to the WHO. Longer intervals between doses within the 8 to 12 week range are associated with greater vaccine efficacy, the agency notes on its website.
Regarding its relationship with the variants of COVID-19, the vaccine has an effectiveness that varies according to the variant.
This Monday, a study by the health authorities of England indicated that having received two doses of the vaccines Pfizer / BioNTech or AstraZeneca / Oxford effectively protects against hospitalization due to the Delta variant of the coronavirus, initially identified in India.
According to this research by Public Health England (PHE), taking two doses of Pfizer / BionTech protects 96% against hospitalizations due to the Delta variant, while Oxford / AstraZeneca offers an efficacy of 92%.
These are “results comparable to the efficacy of the vaccine in preventing hospitalization related to the Alpha variant”, published in December in England.
From April 12 to June 4, the study analyzed the cases of 14,019 people who contracted this variant, of which 166 were hospitalized.
The COVID-19 vaccine developed by AstraZeneca and the University of Oxford, on the other hand, does not seem to protect against mild and moderate cases of the disease caused by the Beta variant of the coronavirus, discovered in South Africa, according to a study cited by the Financial Times newspaper.
With information from AFP and EFE
