On Monday, the Health Council of the Netherlands informed the Dutch government that it saw no objection to administering a dose of the Pfizer / BioNTech vaccine to someone who had already received an AstraZeneca jab.
Recent studies have suggested that it would be safe for people to receive doses of two different coronavirus vaccines. Health Minister Hugo de Jonge had therefore asked the Health Council for their advice on the matter.
A study conducted in the UK - which is yet to be peer-reviewed - found that receiving one dose of AstraZeneca followed by a dose of Pfizer produced the same amount of antibodies than two AstraZeneca doses, or possibly even slightly more. The Health Council have therefore said that the combination of the two vaccines offers “good protection” against serious illness. However, their advice did highlight the fact that those who received a combination of AstraZeneca and Pfizer were more likely to suffer (mild) side effects, such as fatigue, fever, and headaches, but that these symptoms passed within a few days.
Interestingly, research has found that reversing the order of the two jabs and receiving a Pfizer jab followed by an AstraZeneca jab actually resulted in the production of fewer antibodies than two doses of the Pfizer vaccine. The Health Council also emphasised that their latest advice only applied to Pfizer and not Moderna, as according to them there is still “insufficient data” in regards to the efficacy of Moderna when mixed with AstraZeneca.
This research and advice could be relevant to the future of the Dutch vaccination programme, as many experts have suggested it might be necessary to administer a third vaccine dose in order to ensure sufficient protection from COVID-19.
Ernst Kuipers, chairman of the National Acute Care Network (LNAZ), said on Monday that “repeated vaccinations” might be necessary, especially when taking potential future variants into account. “The virus is not going away,” he stated. “You may have to [be vaccinated] again if the effectiveness slowly decreases, or if there are variants against which they protect less well.”
The Health Council’s advice didn’t address the issue of whether it would be logical or sensible to administer a third vaccine dose, but council director Bart-Jan Kullberg told NPO Radio 1 that international research into the matter was already underway. However, taking the results of the UK study into account, it’s likely that if the Netherlands were to administer a third dose, those who have received AstraZeneca would be offered Pfizer.