Trials to check on ‘mixing and matching’ vaccines in the UK

The United Kingdom is conducting a major clinical trial – Com-Cov – to check out the possibility whether different vaccines against COVID- 19 can be mixed and matched for the two doses.

Eight hundred people have been recruited for the study, with efforts to increase the number to 1,050. Those over 50 years of age who have had either a Pfizer or AstraZeneca vaccine first dose are being invited to participate, with the second jab being the same or of Moderna or Novavax.

Combining vaccines might give broader, longer- lasting immunity against the virus and new variants and offer more flexibility to vaccine rollout, the Chief Investigator of the trial, Prof. Matthew Snape, from the Oxford Vaccine Group, has said.

Results of this first stage are expected next month, with reportable finding due from the expanded trial in June or July. The study is scheduled to run for a year.

There is general agreement among health experts that the mixing and matching of the vaccines should be safe. The trial will check for side- effects or unwanted reactions.

Vaccination paused

Denmark has ceased giving the Oxford- AstraZeneca vaccine amid concerns about rare cases of blood clots. This is the first European country to do so fully, while several others had previously briefly suspended the jab.

On Tuesday ( April 13), the United States of America, Canada and the European Union paused the Johnson & Johnson vaccine for similar reasons over “very rare” clotting in patients who received the shot.

South Africa has also paused its use, despite the Johnson & Johnson vaccine being preferred due to its effectiveness against the South African variant.