With new guidelines based on 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 medicines and healthcare products regulator have both identified a possible link between the vaccine from AstraZeneca-University of Oxford and very rare cases of unusual low platelet blood clots.
Neither European nor UK health regulators have recommended age restrictions when using the vaccine. However, the UK regulator noted that the data suggested a slightly higher incidence was reported in the younger adult age groups and therefore recommends taking this evolving evidence 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 also takes into account the pandemic situation and the availability of vaccines in individual countries.
Subsequently, the UK, several EU countries and other governments around the world have moved to recommend the use of alternative vaccines for young people.
Given the changed guidance, younger people are now asking the question: If I have already received a dose of the vaccine, should I come back for the second?
Governments have different answers to this question. Health experts generally agree that mixing and matching the vaccines should be safe. But clinical trials are underway.
Guidance varies
The UK Joint Committee on Vaccination and Immunization advises: “Anyone 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. 19. “
In contrast, the French health regulator recommends that people under 55 who received their first dose of AstraZeneca should receive Pfizer or Moderna for their second injection. It recommends an interval of 12 weeks between this first and second admission in these cases. The regulator stated that there is no reason to fear specific side effects if you had the first AstraZeneca shot and then switched to an mRNA shot for the second.
Germany has followed a similar path. The German Vaccine Commission recommended that people under 60 who had received an injection of the AstraZeneca shot should choose a different vaccine for their second dose.
The Prime Minister of Baden-Wuerttemberg, Winfried Kretschmann (R), will receive the AstraZeneca vaccine against the novel coronavirus in Stuttgart, southern Germany, on March 19, 2021.
MARIJAN MURAT | AFP | Getty Images
Trials are underway
“The guidelines are the guidelines. But as a basic immunologist, can I see any argument as to why it would be unsafe or bad to combine vaccines? No, I don’t see any. It would still generate great immunity. No problem with that,” Danny Altmann, a professor of immunology at Imperial College London, told CNBC’s “Squawk Box Europe” Friday.
Andrew Freedman, an infectious disease reader at Cardiff University’s School of Medicine, told CNBC: “Studies are underway to look at the concept of mix and match. There is no theoretical reason why that should not be feasible and safe,” but we have to wait for these investigations. “
In terms of a possible booster dose that may be needed in the fall or winter, he added, “I don’t think there is any real concern that you wouldn’t be able to follow two doses of the AstraZeneca vaccine with one of these the other, messenger RNA vaccines. ”
Meanwhile, Franz-Werner Haas, the CEO of vaccine maker CureVac told CNBC this week, “The good news is that all of these vaccines code for the same spike protein … so that’s why there are clinical trials and data you can mix and match with these different vaccine platforms. ”
“So in this regard, I have high hopes that this will work out quite well,” he added.
CureVac’s proprietary candidate is still in clinical trials. The data retrieval is on track for the second quarter of this year.
The Centers for Disease Control and Prevention state that the safety and efficacy of a series of blended products have not been evaluated.
Several trials are underway to look at the effects of mixing vaccines. The UK started a trial in February that looked specifically at mixing the AstraZeneca-Oxford vaccine with the Pfizer-BioNtech injection. The findings are not expected to be available until the summer. Separate trials are being conducted with a combination of the vaccines AstraZeneca-Oxford and the Russian Sputnik V.