EU authorises AstraZeneca's COVID-19 vaccine amid supply dispute

The European Commission on Friday granted a conditional marketing authorisation to AstraZeneca and the University of Oxford's AZD1222 for people aged 18 years and older, making it the third COVID-19 vaccine authorised in the EU, following Pfizer and BioNTech's vaccine Comirnaty, as well as Moderna's mRNA-1273. The decision on AZD1222 follows a positive recommendation issued earlier in the day by the European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP).

Ursula von der Leyen, president of the European Commission, stated that "with the AstraZeneca vaccine now authorised, 400 million additional doses will be available in Europe," adding that she expects the company "to deliver these doses as agreed, so that Europeans can be vaccinated as soon as possible."

EU export controls

The authorisation comes amid an escalating dispute between AstraZeneca and EU officials, following the drugmaker's recent disclosure that its vaccine deliveries would be cut to 31 million doses in the first quarter because of lower-than-expected output at a manufacturing site in Belgium. The EU had expected to receive at least 100 million doses, and possibly up 120 million, by the end of March.

On Friday, the European Commission announced it was implementing export controls on COVID-19 vaccines manufactured in the EU. It said the move, which will be in place until the end of March, and only covers products that were ordered by the bloc via advanced purchase agreements, was to address "the current lack of transparency of vaccine exports" and to ensure EU citizens get timely access to the vaccines.

However, AstraZeneca CEO Pascal Soriot has said the volumes agreed with the EU were not a firm commitment, but rather a "best effort." According to Soriot, the EU was relatively late in signing a supply contract with AstraZeneca, so the company did not have enough time to address production problems at a factory run by a partner in Belgium.

Efficacy of 59.5% against symptomatic disease

According to the EMA, the safety of AstraZeneca's vaccine was demonstrated across four studies in the UK, Brazil and South Africa, which included a total of around 24,000 participants, while the CHMP focussed its efficacy analysis on two Phase III trials, the COV002 study in the UK and the COV003 study in Brazil. The agency added that the other two studies had too few cases of COVID-19, with six in each trial, while its review also concentrated on data involving people who received the standard vaccine regimen, with the second dose given between four and 12 weeks after the first.

Results showed that there were 64 cases of symptomatic COVID-19 infections among 5258 vaccinated individuals and 154 cases in the control group of 5210 subjects, translating to a 59.5% reduction of symptomatic COVID-19 for those who received the inoculation. The EMA said efficacy rose slightly to 62.6% in a pre-specified analysis that included participants who received two immunisations within any dose interval, which ranged from three to 23 weeks.

Not enough evidence for older participants

The agency noted that most of the study participants were between 18 and 55 years old, adding that "there are not yet enough results in older participants." Results showed that among participants aged between 56 and 65 years old, eight cases of COVID-19 were reported in those receiving AZD1222, compared to nine cases for control, with two and six cases, respectively, in those older than 65 years of age. Still, the EMA believes protection in people over 55 "is expected, given that an immune response is seen in this age group and based on experience with other vaccines." The agency had wanted 7500 people older than 65 or who had serious health conditions to take part in trials, but AstraZeneca and the University of Oxford did not meet that benchmark. The EMA noted that more information is expected from ongoing studies, which it says include a higher proportion of elderly participants.

Officials advising the German government on immunisation policy recently recommended against administering AstraZeneca's COVID-19 vaccine in people over 65, citing a lack of efficacy data for older adults. The UK authorised emergency supply of AZD1222 for adults last December to be administered as two full doses given four to 12 weeks apart. Mary Ramsay, head of immunisations at Public Health England, recently noted that while "there were too few cases in older people in the AstraZeneca trials to observe precise levels of protection in this group…data on immune responses were very reassuring."

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