Is it safe for countries dealing with COVID-19 vaccine shortages to consider mixing the vaccines to inoculate their citizens from the disease? Countries like Canada, Germany, France, Sweden, Finland, Denmark and Norway are currently mixing vaccines – with either the AstraZeneca-Oxford, Pfizer-BioNTech or Moderna shots being administered interchangeably in certain situations.

Africa is facing a fast-surging third wave of COVID-19 pandemic, and vaccines are increasingly scarce, 47 of Africa’s 54 countries—nearly 90%—are set to miss the September target of vaccinating 10% of their people unless Africa receives 225 million more doses.

In Ghana for instance, only a little over 400,000 people can be described as fully vaccinated while more than 800,000 people await their second dose of the vaccine as the country’s vaccination programme has ground to a halt for the past 8 weeks because of shortages. Meanwhile, the West African nation is in the early stages of experiencing the third wave of COVID-19 infections with the community spread of the Delta variant confirmed.

So, is mixing COVID-19 vaccines an option?


WHO position 

“WHO has not issued a clear recommendation on the use of mixed schedules. We are waiting for additional data to make a firm recommendation,” the WHO told GhanaFact when contacted via the Africa Infodemic Response Alliance (AIRA) secretariat.

Here is an outline of the progress made by the WHO in researching mixing and matching:

  1. On 15th June 2021, WHO’s Strategic Advisory Group of Experts on Immunisation (SAGE) updated its interim recommendations on the Pfizer vaccine to give a permissive recommendation to use the Pfizer vaccine as a second dose following a first dose with the AstraZeneca vaccine if a second dose of AstraZeneca vaccine is not available due to supply constraints or other concerns, the team also told GhanaFact.
  1. A clinical trial led by the University of Oxford, in the UK is currently ongoing to investigate mixing the regimen of the AstraZeneca vaccine and the Pfizer vaccine.
  1. This trial was recently expanded to include the Moderna and Novovax vaccines. CEPI, which leads the R&D aspect of the COVAX facility, announced on May 26 that it will fund an expansion of the clinical trials.


Safety and efficacy of mixing and matching vaccines

The WHO Africa Infodemic Response Alliance told GhanaFact that;

  1. “Preliminary findings from the University of Oxford trial showed that people who received the Astra Zeneca vaccine for their first dose, followed by the Pfizer–BioNTech vaccine as the second dose had a higher likelihood of fever and other typical mild side effects than if they had stayed with 2 doses of the Astra Zeneca vaccine.”

These side effects lasted on average a few days and no hospitalizations occurred. This study was done among people aged 50 and over.

Meanwhile, on July 12, 2021, World Health Organization Chief Scientist -Dr Soumya Swaminathan during an online briefing cautioned individuals who are thinking of mixing and matching vaccines without following guidance from public health authorities.

“Really want to caution folks because there is a tendency now for people in countries with enough availability of vaccine to voluntarily start thinking about an additional dose. There are people who are thinking about mixing and matching. We received a lot queries from people who say they have taken one and they are planning to take another one.  It is a little bit of dangerous trend here, where people are in a data-free evidence-free zone as far as mix and match, there is  limited data on mix and match.”

There are still studies being conducted into mixing and matching and more research and data would be needed to support the safety as yet. However, the tolerability results of some recipients(mix and match) during clinical trials conducted so far show there is no harm in mixing and matching COVID-19 vaccines right now and it helped in boosting the immune response.

“If they are going to do mixing and matching [in Ghana], all those people have to be given oral informed consent about the information we know about mixing and matching. And that decision has to be made with equally serious follow-up.” A Research Fellow in the Department of Health Policy and Management at New York University’s School of Global Public Health, Nana Kofi Quakyi told GhanaFact in an interview.


Researched by Gifty Tracy Aminu