Caregivers and people aged 50/64 with comorbidities: HAS integrates the AstraZeneca vaccine into the strategy

With the arrival of the AZD1222 vaccine (AstraZeneca and Oxford University), vaccination is open to all health and medico-social professionals and people aged 50 to 64, with priority given to patients suffering from comorbidities.

A few days after the conditional marketing authorization (MA) issued by the European Commission, the High Authority for Health (HAS) issued its opinion on February 2 on the integration of the AstraZeneca vaccine into the vaccine strategy.

After those of Pfizer / BioNTech and Moderna, this 3rd vaccine comes "to complete the arsenal" and brings a "message of hope for a way out of the crisis", rejoiced Pr Dominique Le Gudulec, president of the HAS, during of a virtual press briefing.

10 million doses available “within three months”

In total, between 3 and 4 million caregivers and 4 million people aged 50 to 64 suffering from comorbidities (out of the 13 million French people aged 50 to 64) can now claim vaccination. They will have to share the 10 million doses which will be available "in the next three months", according to the president of the HAS.

Easier to store and use, the AZD1222 vaccine in a two-dose schedule can be administered by doctors and nurses, but also by pharmacists and midwives. Although well tolerated, monitoring for 15 minutes after injection is recommended.

To justify its opinion, the HAS relied on the results of several studies that did not present uniform protocols. The differences in the dosages and in the intervals between the injections made it "difficult to summarize the results", explained Pr Élisabeth Bouvet, president of the technical commission for vaccinations.

No vaccination for those 65 and over

This non-replicating adenovirus vaccine nevertheless offers “satisfactory performance”, “between 62 and 70%, depending on the studies”, indicated Professor Le Guludec. Despite a lack of data on its effectiveness in the oldest subjects, the European Medicines Agency (EMA) issued a favorable opinion on the wide use of the vaccine.

The HAS wants to be more cautious and excludes its use in people aged 65 and over until additional data is provided. The results of a trial conducted in the United States with a large population of subjects aged 65 and over should provide answers. The data is expected “in a fortnight”, indicated the president of the HAS, specifying that the opinion would then be revised. In the meantime, mRNA vaccines are to be preferred in this age group.

On the interval between the two doses, and while the EMA opinion indicated a deadline of 4 to 12 weeks, the HAS recommends a spacing of 9 to 12 weeks. The data show that "the effectiveness increases from the 9th week (compared to the 4th week, editor's note)", justifies Pr Daniel Floret, vice-president of the technical commission for vaccinations.

Concomitant administration of another vaccine is also not recommended. An interval of 14 days must be respected to "optimize the response" and "avoid possible interactions", underlines Pr Bouvet.

Towards a single dose for subjects already infected?

For the time being, no data is available on the efficacy of the AZD1222 vaccine on the new variants. There is also a lack of data on its efficacy in immunocompromised subjects and pregnant women. For the latter, it is thus recommended only in the event of significant risk factors.

On the advisability of a single-dose vaccination for people already infected with SARS-CoV-2, the HAS will issue an opinion soon. Recalling that these patients will remain non-priority, Pr Bouvet believes that one dose is “probably” sufficient.

"Being vaccinated should not let your guard down," reminded the president of the HAS, insisting on the protection against the severe forms offered by the vaccines but also on the uncertainties as to their ability to block the transmission of the virus.

Article updated on February 5, 2021