With new guidelines following reports of rare blood clots, the global medical community is considering whether it is possible and safe to administer two different vaccine candidates to the same person.
This week, the European Medicines Agency and the UK’s Medicines and Healthcare Products Regulatory Agency both determined that there is a possible link between the AstraZeneca University of Oxford vaccine and very rare cases of unusual low blood platelet clots.
Neither European nor British health regulators have recommended age restrictions on the use of the vaccine. However, the UK regulator noted that the data suggested that there is a slightly higher incidence in younger age groups, and therefore recommends that this evolving evidence be taken into account when considering the use of the vaccine.
The EMA also reiterated that the vaccine is safe and effective, but noted that the use of the vaccine at national level will also take into account the pandemic situation and the availability of vaccine in the individual countries.
Subsequently, the United Kingdom, various EU countries and other governments around the world decided to use alternative vaccines for younger people.
Given the change in guidance, younger people are now asking the question: if I have already received one dose of the vaccine, should I come back for the second one?
Governments have different answers to this question. Health experts generally agree that the mixing and adaptation of the vaccines should be safe. But clinical trials continue.
The lead varies
The UK Joint Vaccination and Immunization Committee advises: ‘Everyone who has received a first dose of AstraZeneca COVID-19 vaccine should continue to receive a second dose of AstraZeneca COVID-19 vaccine, regardless of age. The second dose will be important for longer lasting protection against COVID-19. “
In contrast, the health regulator in France recommends that people under the age of 55 who received their first dose of AstraZeneca should get Pfizer or Moderna for their second admission. It recommends a gap of 12 weeks between these first and second shots in these cases. The regulator said there is no reason to fear specific adverse events if you had the first AstraZeneca sting and then switched to an mRNA sting for the second.
Germany followed a similar path. The German Vaccination Committee recommended that people under the age of 60 who received one shot of AstraZeneca jab should opt for another vaccine for their second dose.
Baden-Württemberg Premier Winfried Kretschmann (R) receives the AstraZeneca vaccine against the new coronavirus in Stuttgart, southern Germany, on 19 March 2021.
MARIJAN MURAT | AFP | Getty Images
Trials in progress
“The guidelines are the guidelines. Can I as a basic immunologist see any argument as to why it would be unsafe or poor practice to mix and match vaccines? No, I can not see it at all. It will still be a great immunity No problem with that, Danny Altmann, a professor of immunology at Imperial College London, told CNBC’s “Squawk Box Europe” on Friday.
Andrew Freedman, a reader of Infectious Diseases at Cardiff University’s School of Medicine, told CNBC: “The concept of mixing and matching is constantly being investigated. There is no theoretical reason why it can not be feasible and safe. but we have to wait for these studies. ‘
In terms of a possible booster dose that may be needed in the fall or winter, he added: ‘I do not think there is any real concern that you may not be able to follow two doses of the AstraZeneca vaccine with each other. messenger RNA vaccines. ”
Meanwhile, Franz-Werner Haas, CEO of vaccine manufacturer CureVac, told CNBC this week: ‘The good news is that all of these vaccines encode the same vein protein … so clinical trials and data have been seen that you can mix and match at these different vaccine platforms. ”
“So I very much hope that it will work well,” he added.
CureVac’s own candidate is still in clinical trials. Data reading is on track for the second quarter of this year.
The Centers for Disease Control & Prevention claims that the safety and efficacy of a range of blended products have not been evaluated.
Several trials are underway to look at the effects of vaccination of mixtures. The UK launched a trial in February to specifically mix the AstraZeneca-Oxford vaccine with the Pfizer-BioNtech shot. Findings are expected to be available only in the summer. Trials are being held separately to investigate a combination of the AstraZeneca-Oxford and the Russian Sputnik V vaccinations.