The European Medicines Agency has issued guidelines for coronavirus vaccine manufacturers who plan to adapt vaccines already authorized to new variants.
The EU regulator says the three authorized vaccines, made by Pfizer, Moderna and AstraZeneca, “provide protection against the variants that are prevalent in Europe”.
“However, it appears that with continuous mutations and new variants emerging, authorized vaccines may need to be adapted in time to ensure continued protection.”
The variant of most concern today is the one that first appeared in South Africa because of the evidence that it may decrease the effectiveness of vaccines. The so-called British and Brazilian variants are also spreading rapidly.
The EMA says its experts worked on the assumption that the adjusted vaccine would work the same as the original injection, except for a change in the part that triggers the body’s immune response.
He says “large-scale safety and efficacy studies are not needed”, but at least one clinical trial is recommended in people who have not been vaccinated or infected with the coronavirus.
The agency also suggested a study involving a small group randomly selected to receive the parent or variant vaccine to ensure that both elicit similar immune responses.
He says that studies on the use of adjusted vaccines as a booster dose of protection against variants should be carried out, and hopes that manufacturers will provide data on the quality of production of the adjusted vaccines.
Pfizer studying 3rd vaccine
The new guidance comes as Pfizer begins to study whether a third dose of its COVID-19 vaccine can offer protection against mutant versions of the virus, the company said on Thursday.
The pharmaceutical giant said it would offer a third dose to 144 volunteers among participants in the initial test of the vaccine in the United States last year.
He wants to determine whether an additional booster injection given six to 12 months after the first two doses would speed up the immune system enough to ward off a mutant virus.
“Although we have seen no evidence that circulating variants result in the loss of protection provided by our vaccine, we are taking several steps to act decisively and be ready if a strain becomes resistant to the protection afforded by the vaccine,” said the CEO Pfizer, Albert Bourla, in a press release.
“This reinforcement study is critical to understanding the safety of a third dose and immunity against circulating strains,” he added.
Pharmaceutical giants working on updated recipes
At the same time, Pfizer and its German partner, BioNTech, are also improving their vaccine prescription.
The companies said they were in discussions with US and EU regulators over a “study to evaluate a specific vaccine for variants with a modified mRNA sequence. This study would use a new construction of the Pfizer-BioNTech vaccine based on strain B .1,351, first identified in South Africa. “
Pfizer competitor Moderna has already announced Wednesday that it is ready to test experimental doses of its vaccine that better adapt to the South African variant of the virus.
Coronavirus vaccines from Pfizer and Moderna use a technology called mRNA that is easy to update. Their vaccines use a piece of genetic code for the spike protein that lines the virus, so that the immune system can learn to recognize and fight the real virus.
If a variant with a peak mutant protein emerges that the original vaccine cannot recognize, companies would trade that piece of genetic code for a better match – if and when regulators decide it is necessary.
But adjusting other coronavirus vaccines can be more complex. The AstraZeneca injection, for example, uses a harmless version of a cold virus to transport the spike protein gene to the body. An update would require the growth of cold viruses with the updated spike gene.
The US regulator said that studies of the updated COVID-19 vaccines will not have to be as large or as long as for the first generation of vaccines. Instead, a few hundred volunteers could receive experimental doses of an adjusted vaccine, to see if their immune systems react similarly to the updated and original injection.